阅读说明：本技术 用于在单面mri系统中进行体积采集的系统和方法 (System and method for volume acquisition in a single-sided MRI system ) 是由 穆勒·戈麦斯 于 2020-03-25 设计创作，主要内容包括：提供了一种用于执行磁共振成像的方法。该方法包括：提供磁共振成像系统,该磁共振成像系统包括：包括射频接收线圈的射频接收系统,以及外壳,其中,外壳包括用于提供非均匀永久梯度场的永磁体、射频发射系统以及单面梯度线圈组。该方法还包括：将接收线圈放置为靠近目标主体；经由发射系统来施加啁啾脉冲的序列；沿着非均匀永久梯度场施加多切片激励；经由与非均匀永久梯度场正交的梯度线圈组来施加多个梯度脉冲；经由接收系统来采集目标主体的信号,其中,信号包括至少两个啁啾脉冲；以及形成目标主体的磁共振图像。(A method for performing magnetic resonance imaging is provided. The method comprises the following steps: providing a magnetic resonance imaging system comprising: a radio frequency receiving system comprising a radio frequency receiving coil, and a housing, wherein the housing comprises a permanent magnet for providing a non-uniform permanent gradient field, a radio frequency transmitting system, and a single-sided gradient coil set. The method further comprises the following steps: placing a receive coil proximate to a target subject; applying a sequence of chirped pulses via a transmission system; applying a multi-slice excitation along the non-uniform permanent gradient field; applying a plurality of gradient pulses via a gradient coil set orthogonal to the non-uniform permanent gradient field; acquiring a signal of a target subject via a receiving system, wherein the signal comprises at least two chirps; and forming a magnetic resonance image of the target subject.)

1. A method for performing magnetic resonance imaging, comprising:

providing a magnetic resonance imaging system, the magnetic resonance imaging system comprising:

a radio frequency receiving system comprising a radio frequency receiving coil, and

a housing, wherein the housing comprises:

a permanent magnet for providing a non-uniform permanent gradient field,

a radio frequency transmission system, and

a single-sided gradient coil set;

placing the receive coil proximate to a target subject;

applying a sequence of chirped pulses via the transmission system;

applying a multi-slice excitation along the non-uniform permanent gradient field;

applying a plurality of gradient pulses via the gradient coil set orthogonal to the non-uniform permanent gradient field;

acquiring a signal of the target subject via the receiving system, wherein the signal comprises at least two chirps; and

forming a magnetic resonance image of the target subject.

2. The method of claim 1, wherein the chirped pulses, multi-slice excitation, and application of gradient pulses are timed such that magnetization refocuses each time a signal is acquired by the receiving system.

3. The method of claim 1, further comprising a power supply, wherein the power supply is configured to flow a current through at least one of the radio frequency transmission system and the set of single-sided gradient coils to generate an electromagnetic field in a region of interest, wherein the region of interest surrounds the target subject.

4. The method of claim 3, wherein the region of interest has a diameter of 4 to 12 inches.

5. The method of claim 1, wherein the multi-slice excitation comprises exciting a plurality of slices along an axis of the non-uniform permanent gradient field, wherein each of the plurality of slices has a bandwidth of a wide bandwidth similar to the chirped pulse.

6. The method of claim 1, wherein the chirps comprise a same bandwidth and different durations.

7. The method of claim 1, wherein the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

8. The method of claim 1, wherein the chirped pulses are configured to produce a 1-dimensional signal along an axis of the non-uniform permanent gradient field.

9. The method of claim 8, wherein the 1-dimensional signal is a first 1-dimensional signal, the gradient pulses being configured to generate a second 1-dimensional signal and a third 1-dimensional signal that are orthogonal to each other and to an axis of the non-uniform permanent gradient field.

10. The method of claim 1, wherein the gradient pulses are configured for encoding spatial information into the signal.

11. The method of claim 1, wherein a combination of the non-uniform permanent gradient field and the chirped pulses is configured for slice selection among the non-uniform permanent gradients and frequency encoding gradients.

12. The method of claim 1, wherein the target subject is an anatomical part of a body.

13. The method of claim 1, wherein the receive coil comprises an array of receive coils, and each receive coil in the array of receive coils is configured for a particular anatomical part of a body.

14. The method of claim 1, wherein the chirped pulses induce a signal in the target body and the signal is received by the receive coil.

15. The method of claim 1, wherein each of the at least two chirps is split into two components that are 90 degrees out of phase.

16. The method of claim 1, wherein each of the at least two chirps is split into two components, the two components being sent to two separate ports of the transmission system.

17. The method of claim 1, wherein the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with a blanking signal.

18. The method of claim 17, wherein the blanking signal is utilized to turn on and off the control system to enable and disable, respectively, a radio frequency amplifier.

19. The method of claim 3, wherein the radio frequency transmission system comprises a transmission coil that is non-planar and positioned to partially surround the region of interest.

20. The method of claim 19, wherein the magnetic resonance imaging system further comprises a tuning block, wherein the tuning block is configured to change a frequency response of the transmit coil.

21. The method of claim 3, wherein the gradient coil set is non-planar and positioned to partially surround the region of interest, and wherein the gradient coil set is configured to project magnetic field gradients to the region of interest.

22. The method of claim 3, wherein the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within the region of interest.

23. The method of claim 3, wherein the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the receive coil is smaller than the region of interest.

24. The method of claim 19, wherein the transmit coil and the gradient coil set are concentric about the region of interest.

25. A method for performing magnetic resonance imaging, comprising:

providing an imaging system, the imaging system comprising:

a radio frequency receiving coil, and

a permanent magnet for providing a permanent gradient field,

placing the receive coil proximate to a target subject;

applying a sequence of chirped pulses having a wide bandwidth;

applying a multi-slice excitation along the permanent gradient field, wherein the multi-slice excitation comprises exciting a plurality of slices along an axis of the permanent gradient field, wherein each of the plurality of slices has a bandwidth of a wide bandwidth similar to a chirped pulse;

applying phase encoding fields along two orthogonal directions perpendicular to the axis of the permanent gradient field;

acquiring a magnetic resonance image of the target subject.

26. The method of claim 25, wherein the chirped pulses, multi-slice excitation, and application of gradient pulses are timed such that magnetization refocuses each time a signal is acquired.

27. The method of claim 26, wherein each magnetization is focused in a region of interest, wherein the region of interest surrounds the target subject.

28. The method of claim 27, wherein the region of interest has a diameter of 4 to 12 inches.

29. The method of claim 25, wherein the chirped pulses comprise a same bandwidth and different durations.

30. The method of claim 29, wherein the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

31. The method of claim 25, wherein the chirped pulses are configured to produce a 1-dimensional signal along an axis of the permanent gradient field.

32. The method of claim 31, further comprising applying a plurality of gradient pulses via a gradient coil set orthogonal to the non-uniform permanent gradient field, wherein the 1-dimensional signal is a first 1-dimensional signal, the gradient pulses configured to produce second and third 1-dimensional signals orthogonal to each other and to an axis of the permanent gradient field.

33. The method of claim 26, further comprising applying a plurality of gradient pulses via a gradient coil set orthogonal to the non-uniform permanent gradient field, wherein the gradient pulses are configured for encoding spatial information into the signals.

34. The method of claim 25, wherein a combination of the permanent gradient fields and the chirped pulses is configured for slice selection in the permanent and frequency encoding gradients.

35. The method of claim 25, wherein the target subject is an anatomical part of a body.

36. The method of claim 25, wherein the receive coil comprises an array of receive coils, and each receive coil in the array of receive coils is configured for a particular anatomical part of a body.

37. The method of claim 25, wherein the chirped pulses induce a signal in the target body and the signal is received by the receive coil.

38. The method of claim 25, wherein the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with a blanking signal.

39. The method of claim 38, wherein the blanking signal is utilized to turn the system on and off to enable and disable, respectively, the radio frequency amplifier.

40. The method of claim 27, the imaging system further comprising a tuning block and a radio frequency transmit coil, wherein the tuning block is configured to change a frequency response of the transmit coil.

41. The method of claim 40, wherein the transmit coil is non-planar and is positioned to partially surround the region of interest.

42. The method of claim 27, wherein the imaging system further comprises a single-sided gradient coil set, wherein the gradient coil set is non-planar and positioned to partially surround the region of interest, and wherein the gradient coil set is configured to project magnetic field gradients to the region of interest.

43. The method of claim 27, wherein the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within the region of interest.

44. The method of claim 27, wherein the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the receive coil is smaller than the region of interest.

45. A method for performing magnetic resonance imaging, comprising:

providing a permanent gradient magnetic field;

placing a receive coil proximate to a target subject;

applying a sequence of chirped pulses having a wide bandwidth;

selecting slice selection gradients having the same wide bandwidth;

applying a multi-slice excitation technique along an axis of the permanent gradient magnetic field;

applying a plurality of gradient pulses orthogonal to the permanent gradient magnetic field;

acquiring a signal of the target subject via the receive coil; and

forming a magnetic resonance image of the target subject.

46. The method of claim 45, wherein the chirped pulses, multi-slice excitation techniques, and application of gradient pulses are timed such that magnetization refocuses each time the signal is acquired.

47. The method of claim 46, wherein each magnetization is focused in the region of interest, wherein the region of interest surrounds the target subject.

48. The method of claim 47, wherein the region of interest has a diameter of 4 to 12 inches.

49. The method of claim 45, wherein the chirped pulses comprise a same bandwidth and different durations.

50. The method of claim 49, wherein the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

51. The method of claim 45, wherein the chirped pulses are configured to produce a 1-dimensional signal along an axis of the permanent gradient field.

52. The method of claim 51, wherein the 1-dimensional signal is a first 1-dimensional signal, the gradient pulses being configured to generate a second 1-dimensional signal and a third 1-dimensional signal that are orthogonal to each other and to an axis of the permanent gradient field.

53. The method of claim 45, wherein the gradient pulses are configured for encoding spatial information into the signal.

54. The method of claim 45, wherein a combination of the permanent gradient fields and the chirped pulses is configured for slice selection in the permanent and frequency encoding gradients.

55. The method of claim 45, wherein the target subject is an anatomical part of a body.

56. The method of claim 45, wherein the receive coil comprises an array of receive coils, and each receive coil in the array of receive coils is configured for a particular anatomical part of a body.

57. The method of claim 45, wherein the chirped pulses induce a signal in the target body and the signal is received by the receive coil.

58. The method of claim 45, wherein the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with a blanking signal.

59. The method of claim 58, wherein the blanking signal is utilized to turn on and off a system to enable and disable, respectively, the radio frequency amplifier.

60. The method of claim 47, wherein the imaging system further comprises a tuning block and a radio frequency transmit coil, wherein the tuning block is configured to change a frequency response of the transmit coil.

61. The method of claim 60, wherein the transmit coil is non-planar and is positioned to partially surround the region of interest.

62. The method of claim 47 wherein the imaging system further comprises a single-sided gradient coil set, wherein the gradient coil set is non-planar and positioned to partially surround the region of interest, and wherein the gradient coil set is configured to project magnetic field gradients into the region of interest.

63. The method of claim 47, wherein the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within the region of interest.

64. The method of claim 47, wherein the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the receive coil is smaller than the region of interest.

65. A magnetic resonance imaging system comprising:

a radio frequency receiving system comprising a radio frequency receiving coil configured to be placed in proximity to a target subject, wherein the receiving system is configured to deliver a signal of the target subject for forming a magnetic resonance image of the target subject, wherein the signal comprises at least two chirped pulses, and

a housing, wherein the housing comprises:

a permanent magnet for providing a non-uniform permanent gradient field, wherein the imaging system is configured to apply multi-slice excitation along the non-uniform permanent gradient field,

a radio frequency transmission system configured to deliver a sequence of chirped pulses, an

A single-sided gradient coil set configured to deliver a plurality of gradient pulses orthogonal to the non-uniform permanent gradient field.

66. The system of claim 65, further comprising a power supply, wherein the power supply is configured to flow a current through at least one of the radio frequency transmission system and the set of single-sided gradient coils to generate an electromagnetic field in a region of interest, wherein the region of interest surrounds the target subject.

67. The system of claim 66, wherein the region of interest has a diameter of 4 to 12 inches.

68. The method of claim 65, wherein the imaging system is configured to apply a multi-slice excitation comprising exciting a plurality of slices along an axis of a non-uniform permanent gradient field, wherein each of the plurality of slices has a bandwidth of a wide bandwidth similar to the chirped pulse.

69. The system of claim 65, wherein the chirps comprise the same bandwidth and different durations.

70. The system of claim 65, wherein the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

71. The system of claim 65, wherein the chirped pulses are configured to produce a 1-dimensional signal along an axis of the non-uniform permanent gradient field.

72. The system of claim 71, wherein the 1-dimensional signal is a first 1-dimensional signal and the gradient pulses are configured to produce a second 1-dimensional signal and a third 1-dimensional signal that are orthogonal to each other and to an axis of the non-uniform permanent gradient field.

73. The system of claim 65, wherein the gradient pulses are configured for encoding spatial information into the signal.

74. The system of claim 65, wherein the combination of the non-uniform permanent gradient fields and the chirped pulses is configured for slice selection among the non-uniform permanent gradients and frequency encoding gradients.

75. The system of claim 65, wherein the target subject is an anatomical part of a body.

76. The system of claim 65, wherein the receive coil comprises an array of receive coils, and each receive coil in the array of receive coils is configured for a particular anatomical part of a body.

77. The system of claim 65, wherein the chirped pulses induce a signal in the target body, and the receive coil is configured to receive the signal.

78. The system of claim 65, wherein each of the at least two chirped pulses is split into two components that are 90 degrees out of phase.

79. The system of claim 65, wherein the transmission system further comprises two separate ports configured to generate the at least two chirped pulses.

80. The system of claim 65, wherein the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with a blanking signal.

81. The system of claim 80, further comprising a radio frequency amplifier that is enabled and disabled when the control system is turned on and off with the blanking signal.

82. The system of claim 66, wherein the radio frequency transmission system comprises a transmission coil that is non-planar and positioned to partially surround a region of interest.

83. The system of claim 82, wherein the magnetic resonance imaging system further comprises a tuning block, wherein the tuning block is configured to change a frequency response of the transmit coil.

84. The system of claim 66, wherein the gradient coil set is non-planar and positioned to partially surround a region of interest, and wherein the gradient coil set is configured to project magnetic field gradients to the region of interest.

85. The system of claim 66, wherein the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within the region of interest.

86. The system of claim 66, wherein the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the receive coil is smaller than the region of interest.

87. The system of claim 82, wherein the transmit coil and the gradient coil set are concentric about the region of interest.

88. A non-transitory computer-readable medium in which a program for causing a computer to execute a method for performing magnetic resonance imaging is stored, the method comprising:

providing a magnetic resonance imaging system, the magnetic resonance imaging system comprising:

a radio frequency receiving system comprising a radio frequency receiving coil, and

a housing, wherein the housing comprises:

a permanent magnet for providing a non-uniform permanent gradient field,

a radio frequency transmission system, and

a single-sided gradient coil set;

placing the receive coil proximate to a target subject;

applying a sequence of chirped pulses via the transmission system;

applying a multi-slice excitation along the non-uniform permanent gradient field;

applying a plurality of gradient pulses via the gradient coil set orthogonal to the non-uniform permanent gradient field;

acquiring a signal of the target subject via the receiving system, wherein the signal comprises at least two chirps; and

forming a magnetic resonance image of the target subject.

89. The method of claim 88 wherein the chirped pulses, multi-slice excitations, and gradient pulse applications are timed such that magnetization refocuses each time a signal is acquired by the receiving system.

90. The method of claim 88, further comprising a power supply, wherein the power supply is configured to flow a current through at least one of the radio frequency transmission system and the set of single-sided gradient coils to generate an electromagnetic field in a region of interest, wherein the region of interest surrounds the target subject.

91. The method of claim 90, wherein the region of interest has a diameter of 4 to 12 inches.

92. The method of claim 88, wherein the multi-slice excitation comprises exciting a plurality of slices along an axis of the non-uniform permanent gradient field, wherein each of the plurality of slices has a bandwidth of a wide bandwidth similar to the chirped pulse.

93. The method of claim 88, wherein the chirped pulses comprise a same bandwidth and different durations.

94. The method of claim 88, wherein the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

95. The method of claim 88, wherein the chirped pulses are configured to produce a 1-dimensional signal along an axis of the non-uniform permanent gradient field.

96. The method of claim 95, wherein the 1-dimensional signal is a first 1-dimensional signal, the gradient pulses being configured to generate a second 1-dimensional signal and a third 1-dimensional signal that are orthogonal to each other and to an axis of the non-uniform permanent gradient field.

97. The method of claim 88, wherein the gradient pulses are configured for encoding spatial information into the signal.

98. The method of claim 88, wherein the combination of the non-uniform permanent gradient fields and the chirped pulses is configured for slice selection among the non-uniform permanent gradients and frequency encoding gradients.

99. The method of claim 88, wherein the target subject is an anatomical part of a body.

100. The method of claim 88, wherein the receive coil comprises an array of receive coils, and each receive coil in the array of receive coils is configured for a particular anatomical part of a body.

101. The method of claim 88, wherein the chirped pulses induce a signal in the target body and the signal is received by the receive coil.

102. The method of claim 88, wherein each of the at least two chirped pulses is split into two components that are 90 degrees out of phase.

103. The method of claim 88, wherein each of the at least two chirps is split into two components, the two components being sent to two separate ports of the transmission system.

104. The method of claim 88, wherein the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with a blanking signal.

105. The method of claim 104, wherein the blanking signal is utilized to turn on and off the control system to enable and disable, respectively, a radio frequency amplifier.

106. The method of claim 90, wherein the radio frequency transmission system comprises a transmission coil that is non-planar and positioned to partially surround the region of interest.

107. The method of claim 106, wherein the magnetic resonance imaging system further comprises a tuning block, wherein the tuning block is configured to change a frequency response of the transmit coil.

108. The method of claim 90 wherein the gradient coil set is non-planar and positioned to partially surround the region of interest, and wherein the gradient coil set is configured to project magnetic field gradients to the region of interest.

109. The method of claim 90, wherein the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within the region of interest.

110. The method of claim 90, wherein the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the receive coil is smaller than the region of interest.

111. The method of claim 106 wherein the transmit coil and the gradient coil set are concentric about the region of interest.

Background

Embodiments disclosed herein relate generally to systems and methods for efficiently collecting nuclear magnetic resonance spectra and magnetic resonance images in non-uniform fields.

There are several methods for collecting Nuclear Magnetic Resonance (NMR) spectra and Magnetic Resonance (MR) images in inhomogeneous fields. Typically, field non-uniformity is a nuisance to avoid. Non-uniform fields are rarely the source of spatial information. Related methods for imaging in non-uniform fields include the use of wide bandwidth pulses and multi-slice excitation. However, both address the challenges of imaging in non-uniform permanent fields. Accordingly, there is a need for improved methods for collecting NMR spectra and MR images in inhomogeneous fields using bandwidth pulses and multi-slice excitation.

Disclosure of Invention

According to various embodiments, a method for performing magnetic resonance imaging is provided. The method comprises the following steps: providing a magnetic resonance imaging system comprising: a radio frequency receiving system comprising a radio frequency receiving coil, and a housing, wherein the housing comprises a permanent magnet for providing a non-uniform permanent gradient field, a radio frequency transmitting system, and a single-sided gradient coil set. The method further comprises the following steps: placing a receive coil proximate to a target subject; applying a sequence of chirped pulses via a transmission system; applying a multi-slice excitation along the non-uniform permanent gradient field; applying a plurality of gradient pulses via a gradient coil set orthogonal to the non-uniform permanent gradient field; acquiring a signal of a target subject via a receiving system, wherein the signal comprises at least two chirps; and forming a magnetic resonance image of the target subject.

According to various embodiments, a method for performing magnetic resonance imaging is provided. The method includes providing an imaging system, the imaging system including: a radio frequency receive coil, and a permanent magnet for providing a permanent gradient field. The method further comprises the following steps: placing a receive coil proximate to a target subject; applying a sequence of chirped pulses having a wide bandwidth; applying a multi-slice excitation along the permanent gradient field, wherein the multi-slice excitation excites a plurality of slices along an axis of the permanent gradient field, wherein each of the plurality of slices has a bandwidth of a wide bandwidth similar to a chirped pulse; applying phase encoding fields along two orthogonal directions perpendicular to the axis of the permanent gradient field; and acquiring a magnetic resonance image of the target subject.

According to various embodiments, a method for performing magnetic resonance imaging is provided. The method comprises the following steps: providing a permanent gradient magnetic field; placing a receive coil proximate to a target subject; applying a sequence of chirped pulses having a wide bandwidth; selecting slice selection gradients having the same wide bandwidth; applying a multi-slice excitation technique along an axis of the permanent gradient magnetic field; applying a plurality of gradient pulses orthogonal to the permanent gradient magnetic field; acquiring signals of a target subject via a receiving coil; and forming a magnetic resonance image of the target subject.

According to various embodiments, a magnetic resonance imaging system is provided. The system includes a radio frequency receive system including a radio frequency receive coil configured to be placed proximate to a target subject. The receiving system is configured to deliver a signal of the target subject for forming a magnetic resonance image of the target subject, wherein the signal comprises at least two chirped pulses. The system comprises a housing, wherein the housing comprises permanent magnets for providing a non-uniform permanent gradient field. The imaging system is configured to apply multi-slice excitation along the non-uniform permanent gradient field, the radio frequency transmit system is configured to deliver a sequence of chirped pulses, and the single-sided gradient coil set is configured to deliver a plurality of gradient pulses orthogonal to the non-uniform permanent gradient field.

According to various embodiments, a non-transitory computer-readable medium is provided, in which a program is stored for causing a computer to execute a method for performing magnetic resonance imaging. The method comprises the following steps: a magnetic resonance imaging system is provided. The system comprises: a radio frequency receiving system including a radio frequency receiving coil, and a housing. The housing includes a permanent magnet for providing a non-uniform permanent gradient field, a radio frequency transmit system, and a single-sided gradient coil assembly. The method additionally includes: placing a receive coil proximate to a target subject; applying a sequence of chirped pulses via a transmission system; applying a multi-slice excitation along the non-uniform permanent gradient field; applying a plurality of gradient pulses via a gradient coil set orthogonal to the non-uniform permanent gradient field; acquiring a signal of a target subject via a receiving system, wherein the signal comprises at least two chirps; and forming a magnetic resonance image of the target subject.

According to various embodiments, a non-transitory computer-readable medium is provided, in which a program is stored for causing a computer to execute a method for performing magnetic resonance imaging. The method includes providing an imaging system, the imaging system including: a radio frequency receive coil, and a permanent magnet for providing a permanent gradient field. The method further comprises the following steps: placing a receive coil proximate to a target subject; applying a sequence of chirped pulses having a wide bandwidth; applying a multi-slice excitation along the permanent gradient field, wherein the multi-slice excitation excites a plurality of slices along an axis of the permanent gradient field, wherein each of the plurality of slices has a bandwidth of a wide bandwidth similar to a chirped pulse; applying phase encoding fields along two orthogonal directions perpendicular to the axis of the permanent gradient field; and acquiring a magnetic resonance image of the target subject.

According to various embodiments, a non-transitory computer-readable medium is provided, in which a program is stored for causing a computer to execute a method for performing magnetic resonance imaging. The method comprises the following steps: providing a permanent gradient magnetic field; placing a receive coil proximate to a target subject; applying a sequence of chirped pulses having a wide bandwidth; selecting slice selection gradients having the same wide bandwidth; applying a multi-slice excitation technique along an axis of the permanent gradient magnetic field; applying a plurality of gradient pulses orthogonal to the permanent gradient magnetic field; acquiring signals of a target subject via a receiving coil; and forming a magnetic resonance image of the target subject.

These and other aspects and embodiments are discussed in detail below. The foregoing information and the following detailed description include illustrative examples of various aspects and embodiments, and provide an overview or framework for understanding the nature and character of the claimed aspects and embodiments. The accompanying drawings are included to provide an illustration and a further understanding of the various aspects and embodiments, and are incorporated in and constitute a part of this specification.

Brief description of the drawings

The figures are not intended to be drawn to scale. Like reference numbers and designations in the various drawings indicate like elements. For purposes of clarity, not every component may be labeled in every drawing. In the drawings:

figure 1 is a schematic illustration of a magnetic resonance imaging system in accordance with various embodiments.

Figure 2A is a schematic illustration of a magnetic resonance imaging system in accordance with various embodiments.

Figure 2B illustrates an exploded view of the magnetic resonance imaging system shown in figure 2A.

Figure 2C is a schematic front view of the magnetic resonance imaging system shown in figure 2A, in accordance with various embodiments.

Figure 2D is a schematic side view of the magnetic resonance imaging system shown in figure 2A, in accordance with various embodiments.

Fig. 3 is a schematic diagram of an implementation of a magnetic imaging apparatus, in accordance with various embodiments.

Fig. 4 is a schematic diagram of an implementation of a magnetic imaging apparatus, in accordance with various embodiments.

Figure 5 is a schematic elevation view of a magnetic resonance imaging system 500 in accordance with various embodiments.

Fig. 6A is an example schematic illustration of a radio frequency receive coil (RF-RX) array including individual coil elements, in accordance with various embodiments.

Fig. 6B is an example illustration of a loop coil and an example calculation for a loop coil magnetic field, in accordance with various embodiments.

Fig. 6C is an example X-Y graph illustrating a magnetic field as a function of a radius of a toroidal coil, in accordance with various embodiments disclosed herein.

Fig. 6D is a cross-sectional illustration of a portion of a human body (i.e., in the region of the prostate).

Fig. 7A is an example schematic pulse sequence diagram of a two-dimensional pulse sequence in accordance with various embodiments.

Fig. 7B is an example schematic pulse sequence diagram of a three-dimensional pulse sequence in accordance with various embodiments.

Fig. 8 is a schematic pulse sequence diagram of a system utilizing chirped pulses and permanent slice selection gradients, in accordance with various embodiments.

Fig. 9 illustrates an example pulse sequence in accordance with various embodiments.

Figure 10 illustrates example positions of a patient for imaging in a magnetic resonance imaging system, in accordance with various embodiments.

Figure 11 is a schematic illustration of an example magnetic resonance imaging system in accordance with various embodiments.

Figure 12 is a schematic illustration of an example magnetic resonance imaging system in accordance with various embodiments.

Figure 13 is a schematic illustration of an example magnetic resonance imaging system in accordance with various embodiments.

Figure 14 is a schematic illustration of an example magnetic resonance imaging system in accordance with various embodiments.

Figure 15 is a flow diagram of a method for performing magnetic resonance imaging in accordance with various embodiments.

Figure 16 is a flow diagram of another method for performing magnetic resonance imaging in accordance with various embodiments.

Figure 17 is a flow diagram of another method for performing magnetic resonance imaging in accordance with various embodiments.

Fig. 18 is a block diagram illustrating a computer system, in accordance with various embodiments.

It will be appreciated that the figures are not necessarily to scale, nor are the objects in the figures necessarily drawn to scale relative to one another. The figures are depictions that are intended to provide clarity and understanding of various embodiments of the devices, systems, and methods disclosed herein. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Moreover, it should be understood that the drawings are not intended to limit the scope of the present teachings in any way.

Detailed Description

The following description of the various embodiments is merely exemplary and explanatory and is not to be construed as limiting or limiting in any way. Other embodiments, features, objects, and advantages of the present teachings will be apparent from the description and drawings, and from the claims.

It should be appreciated that any use of subheadings herein is for organizational purposes and should not be construed as limiting the application of those subheading features to the various embodiments herein. Each feature described herein may be applicable and usable in all of the various embodiments discussed herein, and all features described herein can be used in any desired combination, regardless of the particular example embodiments described herein. It should further be noted that the exemplary description of a particular feature is used primarily for informational purposes and is not intended to limit in any way the design, sub-features, and functionality of the specifically described feature.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

All publications mentioned herein are incorporated herein by reference for the purpose of describing and disclosing apparatus, compositions, formulations and methodologies which are described in the publications and which might be used in connection with the disclosure.

As used herein, the terms "comprises," "comprising," "includes (third person)," "comprises," "comprising (third person)," "comprises," "having," "has," "with (third person)," and "has" and variations thereof are not intended to be limiting, inclusive or open-ended, and do not exclude additional, unrecited additives, components, integers, elements, or method steps. For example, a process, method, system, composition, kit, or apparatus that comprises a list of features is not necessarily limited to only those features but may include other features not expressly listed or inherent to such process, method, system, composition, kit, or apparatus.

As discussed herein, and in accordance with various embodiments, various systems, and various combinations of features making up various system embodiments, can include a magnetic resonance imaging system. According to various embodiments, the magnetic resonance imaging system is a single-sided magnetic resonance imaging system comprising a magnetic resonance imaging scanner or a magnetic resonance imaging spectrometer. According to various embodiments, a magnetic resonance imaging system can include a magnet assembly for providing a magnetic field required to image an anatomical region of a patient. According to various embodiments, the magnetic resonance imaging system can be configured for imaging in a region of interest present outside the magnet assembly.

A typical magnetic resonance assembly used in modern magnetic resonance imaging systems comprises, for example, a birdcage coil configuration. A typical birdcage configuration includes, for example, a radio frequency transmission (transmit) coil, which can include two large loops located on opposite sides of an imaging region (i.e., a region of interest in which a patient is present), each of the two large loops being electrically connected by one or more rungs. Because the more coils surrounding the patient the more image signal improves, birdcage coils are typically configured to enclose the patient so that the signal generated within the imaging region (i.e., the region of interest in which the patient's anatomical target site is present) is sufficiently uniform. To improve patient comfort and reduce the burdensome motion limits of current magnetic resonance imaging systems, the disclosure as described herein generally relates to magnetic resonance imaging systems including single-sided magnetic resonance imaging systems and applications thereof.

As described herein, the disclosed single-sided magnetic resonance imaging system can be configured to image a patient from one side while providing access to the patient from both sides. This is possible due to the single-sided magnetic resonance imaging system comprising an access aperture (also referred to herein as "aperture", "hole" or "bore") configured to project a magnetic field in a region of interest that is entirely present outside of the magnet assembly and the magnetic resonance imaging system. Because it is not completely surrounded by electromagnetic field generating materials and imaging system components in current prior art systems, the novel single-sided configuration as described herein provides less restriction in patient movement while reducing unnecessary burden during patient sitting and/or removal from the magnetic resonance imaging system. According to various embodiments described herein, with the arrangement of the magnet assembly on the patient side during imaging, the patient does not feel trapped in the disclosed magnetic resonance imaging system. Configurations that enable one-sided or imaging from one side are made possible by the disclosed system components as discussed herein.

System embodiment

In accordance with various embodiments, various systems are disclosed herein, as well as various combinations of features of the various system components and embodiments that make up the disclosed magnetic resonance imaging system.

According to various embodiments, a magnetic resonance imaging system is disclosed herein. According to various embodiments, a system comprises: a housing having a front surface, a permanent magnet for providing a static magnetic field, an access aperture (also referred to herein as an "aperture", "hole" or "bore") within the permanent magnet assembly, a radio frequency transmit coil, and a single-sided gradient coil set. According to various embodiments, a radio frequency transmit coil and a single-sided gradient coil set are positioned proximate to the front surface. According to various embodiments, the system includes an electromagnet, a radio frequency receive coil, and a power source. According to various embodiments, the power supply is configured to flow a current through at least one of the radio frequency transmit coil, the single-sided gradient coil set, or the electromagnet to generate an electromagnetic field in the region of interest. According to various embodiments, the region of interest is present outside the front surface.

According to various embodiments, a radio frequency transmit coil and a single-sided gradient coil set are located on the front surface. According to various embodiments, the front surface is concave. According to various embodiments, the permanent magnet has an aperture through the center of the permanent magnet. According to various embodiments, the static magnetic field of the permanent magnet ranges from 1mT to 1T. According to various embodiments, the static magnetic field of the permanent magnet ranges from 10mT to 195 mT.

According to various embodiments, a radio frequency transmit coil includes first and second rings connected via one or more capacitors and/or one or more rungs. According to various embodiments, the radio frequency transmit coil is non-planar and positioned to partially surround the region of interest. According to various embodiments, the single-sided gradient coil set is non-planar and positioned to partially surround the region of interest. According to various embodiments, a single-sided gradient coil set is configured to project magnetic field gradients to a region of interest. According to various embodiments, the single-sided gradient coil set includes one or more first helical coils at a first location and one or more second helical coils at a second location, the first and second locations being positioned relative to each other around a central region of the single-sided gradient coil set. According to various embodiments, the single-sided gradient coil set has a rise time of less than 10 μ s.

According to various embodiments, the electromagnet is configured to alter the static magnetic field of the permanent magnet within the region of interest. According to various embodiments, the electromagnet has a magnetic field strength of from 10mT to 1T. According to various embodiments, the radio frequency receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within a region of interest. According to various embodiments, the radio frequency receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the coil is smaller than the region of interest. According to various embodiments, the radio frequency transmit coil and the set of single-sided gradient coils are concentric about the region of interest. According to various embodiments, the magnetic resonance imaging system is a single-sided magnetic resonance imaging system including an aperture having an opening positioned about a central region of the front surface.

According to various embodiments, a magnetic resonance imaging system is disclosed herein. According to various embodiments, a system comprises: a housing having a concave front surface, a permanent magnet for providing a static magnetic field, a radio frequency transmit coil, and at least one gradient coil assembly. According to various embodiments, a radio frequency transmit coil and at least one gradient coil set are positioned proximate to the concave front surface. According to various embodiments, the radio frequency transmit coil and the at least one gradient coil set are configured to generate an electromagnetic field in a region of interest. According to various embodiments, the region of interest is present outside the concave front surface. According to various embodiments, the system includes a radio frequency receive coil for detecting signals in the region of interest.

According to various embodiments, a radio frequency transmit coil and a single-sided gradient coil set are located on the concave front surface. According to various embodiments, the static magnetic field of the permanent magnet ranges from 1mT to 1T. According to various embodiments, the static magnetic field of the permanent magnet ranges from 10mT to 195 mT. According to various embodiments, a radio frequency transmit coil includes first and second rings connected via one or more capacitors and/or one or more rungs. According to various embodiments, the radio frequency transmit coil is non-planar and positioned to partially surround the region of interest. According to various embodiments, the at least one gradient coil set is non-planar, single sided, and positioned to partially surround the region of interest. According to various embodiments, the at least one gradient coil set is configured to project magnetic field gradients in the region of interest.

According to various embodiments, the at least one gradient coil set comprises one or more first helical coils at a first location and one or more second helical coils at a second location, the first and second locations being positioned relative to each other around a central region of the at least one gradient coil set. According to various embodiments, at least one gradient coil set has a rise time of less than 10 μ s. According to various embodiments, the permanent magnet has an aperture through the center of the permanent magnet. According to various embodiments, the system additionally includes an electromagnet configured to alter a static magnetic field of the permanent magnet within the region of interest. According to various embodiments, the electromagnet has a magnetic field strength of from 10mT to 1T. According to various embodiments, the radio frequency receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within a region of interest. According to various embodiments, the radio frequency receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the coil is smaller than the region of interest.

According to various embodiments, the radio frequency transmit coil and the at least one gradient coil set are concentric with respect to the region of interest. According to various embodiments, the magnetic resonance imaging system is a single-sided magnetic resonance imaging system comprising a magnetic resonance imaging scanner or a magnetic resonance imaging spectrometer.

Figure 1 is a schematic illustration of a magnetic resonance imaging system 100 in accordance with various embodiments. The system 100 includes a housing 120. As shown in fig. 1, the housing 120 includes a permanent magnet 130, a radio frequency transmit coil 140, a gradient coil assembly 150, an optional electromagnet 160, a radio frequency receive coil 170, and a power supply 180. According to various embodiments, the system 100 can include various electronic components such as, but not limited to, varactors, PIN diodes, capacitors or switches (including micro-electro-mechanical system (MEMS) switches), solid state relays, or mechanical relays. According to various embodiments, the various electronic components listed above can be configured with the radio frequency transmit coil 140.

Figure 2A is a schematic illustration of a magnetic resonance imaging system 200 in accordance with various embodiments. Figure 2B illustrates an exploded view of the magnetic resonance imaging system 200. Figure 2C is a schematic elevation view of a magnetic resonance imaging system 200 in accordance with various embodiments. Figure 2D is a schematic side view of a magnetic resonance imaging system 200 in accordance with various embodiments. As shown in fig. 2A and 2B, the magnetic resonance imaging system 200 includes a housing 220. The housing 220 includes a front surface 225. According to various embodiments, the front surface 225 can be a concave front surface. According to various embodiments, the front surface 225 can be a recessed front surface.

As shown in fig. 2A and 2B, the housing 220 includes a permanent magnet 230, a radio frequency transmit coil 240, a gradient coil set 250, an optional electromagnet 260, and a radio frequency receive coil 270. As shown in fig. 2C and 2D, the permanent magnet 230 can include a plurality of magnets arranged in an array configuration. The plurality of magnets of the permanent magnet 230 are illustrated as covering the entire surface (as shown in the front view of fig. 2C) and as strips in the horizontal direction (as shown in the side view of fig. 2D). As shown in fig. 2A, the primary permanent magnet may include access apertures 235 for accessing the patient from multiple faces of the system.

It should be appreciated that any use of subheadings herein is for organizational purposes and should not be construed as limiting the application of those subheading features to the various embodiments herein. Each feature described herein may be applicable and usable in all of the various embodiments discussed herein, and all features described herein can be used in any desired combination, regardless of the particular example embodiments described herein. It should further be noted that the exemplary description of a particular feature is used primarily for informational purposes and is not intended to limit in any way the design, sub-features, and functionality of the specifically described feature.

Permanent magnet

As discussed herein, and in accordance with various embodiments, various systems, and various combinations of features making up various system embodiments, can include permanent magnets.

According to various embodiments, the permanent magnet 230 provides a static magnetic field in a region of interest 290 (also referred to herein as a "given field of view"). According to various embodiments, the permanent magnet 230 can include a plurality of cylindrical permanent magnets in a parallel configuration, as shown in fig. 2C and 2D. According to various embodiments, the permanent magnet 230 can include any suitable magnetic material, including but not limited to rare earth-based magnetic materials, such as, for example, Nd-based magnetic materials, and the like. As shown in fig. 2A, the primary permanent magnet may include access apertures 235 for accessing the patient from multiple faces of the system.

According to various embodiments, the static magnetic field of the permanent magnet 230 may vary from about 50mT to about 60mT, from about 45mT to about 65mT, from about 40mT to about 70mT, from about 35mT to about 75mT, from about 30mT to about 80mT, from about 25mT to about 85mT, from about 20mT to about 90mT, from about 15mT to about 95mT, and from about 10mT to about 100mT for a given field of view. The magnetic field may also vary from about 10mT to about 15mT, from about 15mT to about 20mT, from about 20mT to about 25mT, from about 25mT to about 30mT, from about 30mT to about 35mT, from about 35mT to about 40mT, from about 40mT to about 45mT, from about 45mT to about 50mT, from about 50mT to about 55mT, from about 55mT to about 60mT, from about 60mT to about 65mT, from about 65mT to about 70mT, from about 70mT to about 75mT, from about 75mT to about 80mT, from about 80mT to about 85mT, from about 85mT to about 90mT, from about 90mT to about 95mT, and from about 95mT to about 100 mT. According to various embodiments, the static magnetic field of permanent magnet 230 may also vary from about 1mT to about 1T, from about 10mT to about 195mT, from about 15mT to about 900mT, from about 20mT to about 800mT, from about 25mT to about 700mT, from about 30mT to about 600mT, from about 35mT to about 500mT, from about 40mT to about 400mT, from about 45mT to about 300mT, from about 50mT to about 200mT, from about 50mT to about 100mT, from about 45mT to about 100mT, from about 40mT to about 100mT, from about 35mT to about 100mT, from about 30mT to about 100mT, from about 25mT to about 100mT, from about 20mT to about 100mT, and from about 15mT to about 100 mT.

According to various embodiments, the permanent magnet 230 can include a hole 235 in its center. According to various embodiments, the permanent magnet 230 may not include holes. According to various embodiments, the holes 235 can have a diameter between 1 inch and 20 inches. According to various embodiments, the holes 235 can have a diameter of between 1 inch and 4 inches, between 4 inches and 8 inches, and between 10 inches and 20 inches. According to various embodiments, a given field of view can be a spherical or cylindrical field of view, as shown in fig. 2A and 2B. According to various embodiments, the diameter of the spherical field of view can be between 2 inches and 20 inches. According to various embodiments, the spherical field of view can have a diameter of between 1 inch and 4 inches, between 4 inches and 8 inches, and between 10 inches and 20 inches. According to various embodiments, the cylindrical field of view is approximately between 2 inches and 20 inches in length. According to various embodiments, the cylindrical field of view can have a length of between 1 inch and 4 inches, between 4 inches and 8 inches, and between 10 inches and 20 inches.

It should be appreciated that any use of subheadings herein is for organizational purposes and should not be construed as limiting the application of those subheading features to the various embodiments herein. Each feature described herein may be applicable and usable in all of the various embodiments discussed herein, and all features described herein can be used in any desired combination, regardless of the particular example embodiments described herein. It should further be noted that the exemplary description of a particular feature is used primarily for informational purposes and is not intended to limit in any way the design, sub-features, and functionality of the specifically described feature.

Radio frequency transmitting coil

As discussed herein, and in accordance with various embodiments, various systems, and various combinations of features making up various system embodiments, can also include a radio frequency transmit coil.

Fig. 3 is a schematic diagram of an implementation of a magnetic imaging apparatus 300, in accordance with various embodiments. As shown in fig. 3, the apparatus 300 includes a radio frequency transmit coil 320, the radio frequency transmit coil 320 projecting RF power outward from the coil 320. The coil 320 has two loops 322 and 324 connected by one or more rungs 326. As shown in fig. 3, coil 320 is also connected to a power supply 350a and/or a power supply 350b (collectively referred to herein as "power supply 350"). According to various embodiments, the power supplies 350a and 350b can be configured for power input and/or signal input, and can be generally referred to as coil input. According to various embodiments, the power sources 350a and/or 350b are configured to provide contact via the electrical contacts 352a and/or 352b (collectively referred to herein as "electrical contacts 352") and the electrical contacts 354a and/or 354b (collectively referred to herein as "electrical contacts 354 b") by attaching the electrical contacts 352 and 354 to one or more rungs 326. The coil 320 is configured to project a uniform RF field within the field of view 340. According to various embodiments, the field of view 340 is a region of interest (i.e., an imaging region) for magnetic resonance imaging in which a patient is present. Because the patient is present in the field of view 340 remote from the coil 320, the apparatus 300 is suitable for use in a single-sided magnetic resonance imaging system. According to various embodiments, the coil 320 can be powered by two signals that are 90 degrees out of phase with each other (e.g., via quadrature excitation).

According to various embodiments, coil 320 includes a loop 322 and a loop 324 positioned coaxially along the same axis, but at a distance away from each other, as shown in fig. 3. According to various embodiments, the loops 322 and 324 are separated by a distance ranging from about 0.1m to about 10 m. According to various embodiments, the loops 322 and 324 are separated by a distance ranging from about 0.2m to about 5m, about 0.3m to about 2m, about 0.2m to about 1m, about 0.1m to about 0.8m, or about 0.1m to about 1m, including any separation distance therebetween. According to various embodiments, coil 320 includes loops 322 and 324, loops 322 and 324 being positioned non-coaxially, but in the same direction, and separated by a distance ranging from about 0.2m to about 5 m. According to various embodiments, the loops 322 and 324 can also be tilted with respect to each other. According to various embodiments, the tilt angle can be from 1 to 90 degrees, from 1 to 5 degrees, from 5 to 10 degrees, from 10 to 25 degrees, from 25 to 45 degrees, and from 45 to 90 degrees.

According to various embodiments, the rings 322 and 324 have the same diameter. According to various embodiments, the loops 322 and 324 have different diameters, and the loop 322 has a larger diameter than the loop 324, as shown in fig. 3. According to various embodiments, the loops 322 and 324 have different diameters, and the loop 322 has a smaller diameter than the loop 324. According to various embodiments, loops 322 and 324 of coil 320 are configured to: the imaging region is generated in a field of view 340 that encompasses a uniform RF power distribution within the field of view 340, a field of view that is not centered in the RF-TX coil, but is projected out in space from the coil itself.

According to various embodiments, the loop 322 has a diameter between about 10 μm and about 10 m. According to various embodiments, the rings 322 have a diameter of between about 0.001m and about 9m, between about 0.01m and about 8m, between about 0.03m and about 6m, between about 0.05m and about 5m, between about 0.1m and about 3m, between about 0.2m and about 2m, between about 0.3m and about 1.5m, between about 0.5m and about 1m, or between about 0.01m and about 3m, including any diameter therebetween.

According to various embodiments, the ring 324 has a diameter between about 10 μm and about 10 m. According to various embodiments, the ring 324 has a diameter of between about 0.001m and about 9m, between about 0.01m and about 8m, between about 0.03m and about 6m, between about 0.05m and about 5m, between about 0.1m and about 3m, between about 0.2m and about 2m, between about 0.3m and about 1.5m, between about 0.5m and about 1m, or between about 0.01m and about 3m, including any diameter therebetween.

According to various embodiments, loops 322 and 324 are connected by one or more rungs 326, as shown in FIG. 3. According to various embodiments, one or more rungs 326 are connected to the loops 322 and 324 to form a single electronic circuit loop (or a single current loop). As shown in fig. 3, for example, one end of one or more rungs 326 is connected to an electrical contact 352 of a power supply 350 and the other end of one or more rungs 326 is connected to an electrical contact 354 such that the coil 320 completes an electronic circuit.

According to various embodiments, the loop 322 is a non-continuous loop, and the electrical contact 352 and the electrical contact 354 can be electrically connected to two opposing ends of the loop 322 to form an electronic circuit powered by the power source 350. Similarly, according to various embodiments, the ring 324 is a non-continuous ring, and the electrical contacts 352 and 354 can be electrically connected to two opposing ends of the ring 324 to form an electronic circuit powered by the power source 350.

According to various embodiments, the rings 322 and 324 are not circular, but can have an elliptical, square, rectangular, or trapezoidal cross-section, or any shape or form having a closed loop. According to various embodiments, the rings 322 and 324 may have a cross-section that varies in two different axial planes, where the major axis is a circle and the minor axis has a sinusoidal shape or some other geometry. According to various embodiments, the coil 320 may include more than two loops 322 and 324, each connected by rungs that span and connect all of the loops. According to various embodiments, the coil 320 may include more than two loops 322 and 324, each connected by rungs that alternate connection points between the loops. According to various embodiments, ring 322 may contain a physical aperture for access. According to various embodiments, the ring 322 may be a solid plate without a physical aperture.

According to various embodiments, the coil 320 generates an electromagnetic field (also referred to herein as a "magnetic field") strength of between about 1 μ T and about 10 mT. According to various embodiments, the coil 320 is capable of generating magnetic field strengths of between about 10 μ T and about 5mT, between about 50 μ T and about 1mT, or between about 100 μ T and about 1mT, including any magnetic field strengths therebetween.

According to various embodiments, the coil 320 generates an electromagnetic field that is pulsed at a radio frequency between about 1kHz and about 2 GHz. According to various embodiments, the coil 320 generates a magnetic field pulsed at a radio frequency between about 1kHz and about 1GHz, between about 10kHz and about 800MHz, between about 50kHz and about 300MHz, between about 100kHz and about 100MHz, between about 10kHz and about 10MHz, between about 10kHz and about 5MHz, between about 1kHz and about 2MHz, between about 50kHz and about 150kHz, between about 80kHz and about 120kHz, between about 800kHz and about 1.2MHz, between about 100kHz and about 10MHz, or between about 1MHz and about 5MHz, including any frequency therebetween.

According to various embodiments, the coil 320 is positioned to partially surround the region of interest. According to various embodiments, the loops 322, 324, and one or more rungs 326 are non-planar with respect to one another. That is, the ring 322, the ring 324, and the one or more rungs 326 form a three-dimensional structure surrounding a region of interest in which a patient resides. According to various embodiments, the loop 322 is closer to the region of interest than the loop 324, as shown in fig. 3. According to various embodiments, the region of interest has a size of about 0.1m to about 1 m. According to various embodiments, the region of interest is smaller than the diameter of the ring 322. According to various embodiments, the region of interest is smaller than both the diameter of the loop 324 and the diameter of the loop 322, as shown in fig. 3. According to various embodiments, the region of interest has a size that is smaller than the diameter of the loop 322 and larger than the diameter of the loop 324.

According to various embodiments, the loops 322, 324, or the rungs 326 comprise the same material. According to various embodiments, the loops 322, 324, or the rungs 326 comprise different materials. According to various embodiments, the rings 322, 324, or the crosspieces 326 comprise hollow or solid tubes. According to various embodiments, hollow or solid tubes can be configured for air or fluid cooling. According to various embodiments, each of the loops 322 or 324 or rungs 326 includes one or more conductive windings. According to various embodiments, the winding comprises a litz wire or any electrical conductor. These additional windings can be used to improve performance by reducing the resistance of the windings at the desired frequency. According to various embodiments, the loops 322, 324, or rungs 326 comprise copper, aluminum, silver paste, or any highly conductive material, including metals, alloys, or superconducting metals, alloys, or non-metals. According to various embodiments, the loops 322, 324, or the rungs 326 may comprise a metamaterial.

According to various embodiments, the rings 322, 324, or the rungs 326 may contain individual electrically insulated thermal control channels designed to maintain the temperature of the structure at a specified setting. According to various embodiments, the thermal control channels can be made of electrically conductive material and integrated to carry electrical current.

According to various embodiments, the coil 320 includes one or more electronic components for tuning the magnetic field. The one or more electronic components can include varactors, PIN diodes, capacitors or switches (including micro-electro-mechanical system (MEMS) switches), solid state relays, or mechanical relays. According to various embodiments, the coil can be configured to include any of one or more electronic components along the electronic circuit. According to various embodiments, one or more components can include a mu metal, a dielectric, a magnetic or a metallic component that does not actively conduct electricity, and the coil can be tuned. According to various embodiments, the one or more electronic components for tuning comprise at least one of a dielectric, a conductive metal, a metamaterial, or a magnetic metal. According to various embodiments, tuning the electromagnetic field includes changing a current or by changing a physical location of one or more electronic components. According to various embodiments, the coils are cryogenically cooled to reduce electrical resistance and improve efficiency. According to various embodiments, the first and second loops comprise a plurality of windings or litz wire.

According to various embodiments, the coil 320 is configured for a magnetic resonance imaging system having magnetic field gradients across a field of view. The field gradients allow imaging of slices of the field of view without the use of additional electromagnetic gradients. As disclosed herein, the coils can be configured to generate a large bandwidth by combining multiple center frequencies each having their own bandwidth. By superimposing these multiple center frequencies with their respective bandwidths, the coil 320 is able to effectively generate a large bandwidth in the desired frequency range between about 1kHz and about 2 GHz. According to various embodiments, the coil 320 generates a magnetic field pulsed at a radio frequency between about 10kHz and about 800MHz, between about 50kHz and about 300MHz, between about 100kHz and about 100MHz, between about 10kHz and about 10MHz, between about 10kHz and about 5MHz, between about 1kHz and about 2MHz, between about 50kHz and about 150kHz, between about 80kHz and about 120kHz, between about 800kHz and about 1.2MHz, between about 100kHz and about 10MHz, or between about 1MHz and about 5MHz, including any frequency therebetween.

It should be appreciated that any use of subheadings herein is for organizational purposes and should not be construed as limiting the application of those subheading features to the various embodiments herein. Each feature described herein may be applicable and usable in all of the various embodiments discussed herein, and all features described herein can be used in any desired combination, regardless of the particular example embodiments described herein. It should further be noted that the exemplary description of a particular feature is used primarily for informational purposes and is not intended to limit in any way the design, sub-features, and functionality of the specifically described feature.

Gradient coil assembly

As discussed herein, and in accordance with various embodiments, various systems, and various combinations of features making up various system embodiments, can also include gradient coil sets.

Fig. 4 is a schematic diagram of an implementation of a magnetic imaging apparatus 400, in accordance with various embodiments. As shown in fig. 4, the apparatus 400 includes a gradient coil set 420 (also referred to herein as a single-sided gradient coil set 420), the gradient coil set 420 configured to project gradient magnetic fields outwardly from the coil set 420 and within a field of view 430. According to various embodiments, the field of view 430 is a region of interest for magnetic resonance imaging (i.e., an imaging region) in which the patient resides. Because the patient is present in the field of view 430 remote from the coil assembly 420, the apparatus 400 is suitable for use in a single-sided MRI system.

As shown in this figure, coil set 420 includes different sized ones of the respective sets of spiral coils 440a, 440b, 440c, and 440d (collectively referred to as "spiral coils 440"). Each set of spiral coils 440 includes at least one spiral coil, and fig. 4 is shown to include 3 spiral coils. According to various embodiments, each of the spiral coils 440 has an electrical contact at its center and an electrical contact output at the outer edge of the spiral coil to form a single run loop of conductive material spiraling outward (or vice versa) from the center to the outer edge. According to various embodiments, each of the spiral coils 440 has a first electrical contact at a first location of the spiral coil and a second electrical contact at a second location of the spiral coil to form a single operational loop of conductive material from the first location to the second location (or vice versa).

As shown in fig. 4, the coil assembly 420 also includes an aperture 425 at its center, with the helical coil 440 disposed around the aperture 425. The aperture 425 itself does not contain any coil material therein for generating the magnetic material. The coil assembly 420 also includes an opening 427 on an outer edge of the coil assembly 420 to which the spiral coil 440 can be disposed. That is, aperture 425 and opening 427 define the boundaries of coil assembly 420 within which spiral coil 440 can be disposed. According to various embodiments, the coil assembly 420 forms a bowl shape with a hole in the center.

According to various embodiments, the helical coil 440 is formed across the aperture 425. For example, the spiral coil 440a is disposed opposite the spiral coil 440c with respect to the aperture 425. Similarly, the spiral coil 440b is disposed opposite the spiral coil 440d with respect to the aperture 425. According to various embodiments, the helical coils 440 in the coil set 420 shown in fig. 4 are configured to create a spatial encoding in the magnetic gradient field within the field of view 430.

As shown in fig. 4, the coil assembly 420 is also connected to the power supply 450 via electrical contacts 452 and 454 by attaching the electrical contacts 452 and 454 to the one or more helical coils 440. According to various embodiments, the electrical contact 452 is connected to one of the spiral coils 440, which one of the spiral coils 440 is then connected to the other spiral coils 440 in series and/or in parallel, and one of the other spiral coils 440 is then connected to the electrical contact 454 to form an electronic current loop. According to various embodiments, the spiral coils 440 are all electrically connected in series. According to various embodiments, the spiral coils 440 are all electrically connected in parallel. According to various embodiments, some of the spiral coils 440 are electrically connected in series, while other spiral coils 440 are electrically connected in parallel. According to various embodiments, the spiral coils 440a are electrically connected in series, while the spiral coils 440b are electrically connected in parallel. According to various embodiments, the spiral coils 440c are electrically connected in series, while the spiral coils 440d are electrically connected in parallel. The electrical connections between each of the helical coils 440 or each set of helical coils 440 can be configured as desired to generate a magnetic field in the field of view 430.

According to various embodiments, the coil assembly 420 includes a helical coil 440 that is deployed as shown in fig. 4. According to various embodiments, each set of spiral coils 440a, 440b, 440c, and 440d is configured in a row from aperture 425 to opening 427 such that the spiral coils of each set are separated from one another by an angle of 90 °. According to various embodiments, 440a and 440b are disposed at 45 ° relative to each other, and 440c and 440d are disposed at 45 ° relative to each other, while 440c is disposed at 135 ° on the other side of 440b, and 440d is disposed at 135 ° on the other side of 440 a. Essentially, any set of spiral coils 440 can be configured in any arrangement for any number "n" in the set of spiral coils 440.

According to various embodiments, the helical coils 440 have the same diameter. According to various embodiments, each of the sets of spiral coils 440a, 440b, 440c, and 440d has the same diameter. According to various embodiments, the helical coils 440 have different diameters. According to various embodiments, each of the sets of spiral coils 440a, 440b, 440c, and 440d has a different diameter. According to various embodiments, each helical coil in the set of helical coils 440a, 440b, 440c, and 440d has a different diameter. According to various embodiments, 440a and 440b have the same first diameter, and 440c and 440d have the same second diameter, but the first and second diameters are not the same.

According to various embodiments, each of the spiral coils 440 has a diameter between about 10 μm and about 10 m. According to various embodiments, each of the spiral-shaped coils 440 has a diameter between about 0.001m and about 9m, between about 0.005m and about 8m, between about 0.01m and about 6m, between about 0.05m and about 5m, between about 0.1m and about 3m, between about 0.2m and about 2m, between about 0.3m and about 1.5m, between about 0.5m and about 1m, or between about 0.01m and about 3m, including any diameter therebetween.

According to various embodiments, the spiral coils 440 are connected to form a single electronic circuit loop (or a single current loop). As shown in fig. 4, for example, one of the spiral coils 440 is connected to an electrical contact 452 of the power supply 450 and the other spiral coil is connected to an electrical contact 454 such that the spiral coil 440 completes an electronic circuit.

According to various embodiments, the coil assembly 420 generates an electromagnetic field strength (also referred to herein as an "electromagnetic field gradient" or "gradient magnetic field") of between about 1 μ T and about 10T. According to various embodiments, the coil assembly 420 can generate an electromagnetic field strength of between about 100 μ T and about 1T, between about 1mT and about 500mT, or between about 10mT and about 100mT, including any magnetic field strength therebetween. According to various embodiments, the coil assembly 420 can generate electromagnetic field strengths greater than about 1 μ T, about 10 μ T, about 100 μ T, about 1mT, about 5mT, about 10mT, about 20mT, about 50mT, about 100mT, or about 500 mT.

According to various embodiments, the coil assembly 420 generates an electromagnetic field that is pulsed at a rate having a rise time of less than about 100 μ β. According to various embodiments, the coil assembly 420 generates electromagnetic fields that are pulsed at a rate having a rise time of less than about 1 μ s, about 5 μ s, about 10 μ s, about 20 μ s, about 30 μ s, about 40 μ s, about 50 μ s, about 100 μ s, about 200 μ s, about 500 μ s, about 1ms, about 2ms, about 5ms, or about 10 ms.

According to various embodiments, the set of coils 420 is positioned to partially surround a region of interest in the field of view 430. According to various embodiments, the helical coils 440 are non-planar with respect to each other. According to various embodiments, the sets of spiral coils 440a, 440b, 440c, and 440d are non-planar with respect to each other. That is, the helical coil 440 and each of the set of helical coils 440a, 440b, 440c, and 440d form a three-dimensional structure around a region of interest in the field of view 430 in which the patient resides.

According to various embodiments, the helical coil 440 comprises the same material. According to various embodiments, the helical coil 440 comprises different materials. According to various embodiments, the spiral-shaped coils in set 440a comprise the same first material, the spiral-shaped coils in set 440b comprise the same second material, the spiral-shaped coils in set 440c comprise the same third material, and the spiral-shaped coils in set 440d comprise the same fourth material, but the first, second, third, and fourth materials are different materials. According to various embodiments, the first and second materials are the same material, however, the same material is different from the third and fourth materials (which are the same). Essentially, any of the spiral coils 440 can have the same material or different materials, depending on the configuration of the coil assembly 420.

According to various embodiments, the helical coil 440 comprises a hollow or solid tube. According to various embodiments, the helical coil 440 includes one or more windings. According to various embodiments, the winding comprises a litz wire or any electrical conductor. According to various embodiments, spiral coil 440 comprises copper, aluminum, silver paste, or any highly conductive material (including metals, alloys, or superconducting metals, alloys, or non-metals). According to various embodiments, the helical coil 440 comprises a metamaterial.

According to various embodiments, the coil assembly 420 includes one or more electronic components for tuning the magnetic field. The one or more electronic components can include PIN diodes, mechanical relays, solid state relays, or switches, including micro-electro-mechanical system (MEMS) switches. According to various embodiments, the coil can be configured to include any of one or more electronic components along the electronic circuit. According to various embodiments, the one or more components can include a mu metal, a dielectric, a magnetic or a metallic component that does not actively conduct electricity, and the coil can be tuned. According to various embodiments, the one or more electronic components for tuning comprise at least one of a conductive metal, a metamaterial, or a magnetic metal. According to various embodiments, tuning the electromagnetic field includes changing a current or by changing a physical location of one or more electronic components. In some embodiments, the coils are cryogenically cooled to reduce electrical resistance and improve efficiency.

It should be appreciated that any use of subheadings herein is for organizational purposes and should not be construed as limiting the application of those subheading features to the various embodiments herein. Each feature described herein may be applicable and usable in all of the various embodiments discussed herein, and all features described herein can be used in any desired combination, regardless of the particular example embodiments described herein. It should further be noted that the exemplary description of a particular feature is used primarily for informational purposes and is not intended to limit in any way the design, sub-features, and functionality of the specifically described feature.

Electromagnet

As discussed herein, and in accordance with various embodiments, various systems, and various combinations of features making up various system embodiments, can also include electromagnets.

Figure 5 is a schematic elevation view of a magnetic resonance imaging system 500 in accordance with various embodiments. According to various embodiments, the system 500 can be any magnetic resonance imaging system, including, for example, a single-plane magnetic resonance imaging system including a magnetic resonance imaging scanner or a magnetic resonance imaging spectrometer, as disclosed herein.

As shown in fig. 5, the system 500 includes a housing 520 that can house various components, including, for example, but not limited to, magnets, electromagnets, coils for generating a radio frequency field, such as, but not limited to, various electronic components for control, power supply, and/or monitoring of the system 500. According to various embodiments, the housing 520 can house, for example, the permanent magnet 230, the radio frequency transmit coil 240, and/or the gradient coil assembly 250 within the housing 520. According to various embodiments, system 500 also includes a hole 535 in its center. As shown in fig. 5, the housing 520 also includes a front surface 525 of the system 500. According to various embodiments, the front surface 525 can be curved, flat, concave, convex, or otherwise have a straight or curved surface. According to various embodiments, the magnetic resonance imaging system 500 can be configured to provide a region of interest in the field of view 530.

As shown in fig. 5, the system 500 includes an electromagnet 560 disposed proximate a front surface 525 of the system 500. According to various embodiments, the electromagnet 560 is disposed proximate to the center of the front surface 525 on the front side of the system 500. According to various embodiments, the electromagnet 560 can be a solenoid coil configured to generate a field that is added to or subtracted from the magnetic field of the permanent magnet 230, for example. According to various embodiments, the field is capable of generating a pre-polarizing field for enhancing signal or contrast from nuclear magnetic resonance.

As shown in fig. 5, a given field of view 530 exists at the center of a front surface 525 of the system 500. According to various embodiments, the electromagnets 560 are arranged within a given field of view 530. According to various embodiments, the electromagnets 560 are arranged concentrically with a given field of view 530. According to various embodiments, the electromagnet 560 can be inserted into the hole 535. According to various embodiments, the electromagnet 560 can be placed proximate to the aperture 535. For example, the electromagnet 560 can be placed in front of, behind, or in the middle of the aperture 535. According to various embodiments, the electromagnet 560 can be positioned proximate to or at the entrance of the aperture 535.

It should be appreciated that any use of subheadings herein is for organizational purposes and should not be construed as limiting the application of those subheading features to the various embodiments herein. Each feature described herein may be applicable and usable in all of the various embodiments discussed herein, and all features described herein can be used in any desired combination, regardless of the particular example embodiments described herein. It should further be noted that the exemplary description of a particular feature is used primarily for informational purposes and is not intended to limit in any way the design, sub-features, and functionality of the specifically described feature.

Radio frequency receiving coil

As discussed herein, and in accordance with various embodiments, various systems, and various combinations of features making up various system embodiments, can also include a radio frequency receive coil.

Typical MR systems produce a uniform field within the imaging region. The uniform field then generates a narrow band of magnetic resonance frequencies that can then be captured by the receive coil, amplified, and digitized by the spectrometer. Because the frequencies are within a narrow, well-defined bandwidth, the hardware architecture focuses on producing a statically-tuned RF-RX coil with the best coil quality factor. Many variations in coil architecture have been generated that discuss large single-coil coils, coil arrays, parallel coil arrays, or body-specific coil arrays. However, these structures are all based on imaging a specific frequency close to the region of interest at high field strength and as small as possible within the magnetic bore.

According to various embodiments, an MRI system is provided that can include a unique imaging region that is offset from the surface of the magnetic piece and thus unobstructed as compared to conventional scanners. Furthermore, the form factor can have built-in magnetic field gradients that produce a range of field values over the region of interest. Finally, the system is capable of operating at lower magnetic field strengths compared to typical MRI systems, which allows for the mitigation of RX coil design constraints and allows robotically-like additional mechanisms to be used for MRI.

According to various embodiments, the unique architecture of the main magnetic field of the MRI system can yield a different set of optimization constraints. Because the imaging volume now expands over a wider range of magnetic resonance frequencies, the hardware can be configured to be sensitive to and capture specific frequencies generated over the field of view. This frequency range is typically much larger than the frequency range to which a single receive coil tuned to a single frequency is sensitive. Furthermore, because the field strength can be much lower than in conventional systems, and because the signal strength can be proportional to the field strength, it is advantageous to consider maximizing the signal-to-noise ratio of the receive coil network as a whole. According to various embodiments, a method is therefore provided that acquires the full frequency range generated within the field of view without loss of sensitivity.

According to various embodiments, several methods are provided that enable imaging within an MRI system. These methods can include combining: 1) a variably tuned RF-RX coil; 2) an RF-RX coil array having elements tuned to a frequency dependent on the spatial inhomogeneity of the magnetic field; 3) designing an ultra-low noise preamplifier; and 4) an RF-RX array with multiple receive coils designed to optimize signals from a defined and limited field of view for a particular body part. These methods can be combined in any combination as desired.

According to various embodiments, the variably-tuned RF-RX coil can include one or more electronic components for tuning the electromagnetic receive field. According to various embodiments, the one or more electronic components can include at least one of a varactor, a PIN diode, a capacitor, an inductor, a MEMS switch, a solid state relay, or a mechanical relay. According to various embodiments, the one or more electronic components for tuning can include at least one of a dielectric, a capacitor, an inductor, a conductive metal, a metamaterial, or a magnetic metal. According to various embodiments, tuning the electromagnetic receiving field includes changing the current or by changing the physical location of one or more electronic components. According to various embodiments, the coils are cryogenically cooled to reduce electrical resistance and improve efficiency.

According to various embodiments, the RF-RX array can be composed of independent coil elements, each tuned to various frequencies. A suitable frequency can be selected, for example for matching the frequency of the magnetic field at a particular spatial location at which a particular coil is located. Because the magnetic field can vary with space, as shown in fig. 6A, the field and frequency of the coil can be adjusted to approximately match the spatial location. Here, the coils can be designed to image field locations B1, B2, and B3 that are physically separated along a single axis.

For this low-field system, according to various embodiments, a low-noise preamplifier can be designed and configured to balance the low-signal environment of the MRI system. The low noise amplifier can be configured to utilize components that do not generate significant electronic and voltage noise at the desired frequency (e.g., <3MHz and >2 MH). Typical junction field effect transistor designs (J-FETs) generally do not have suitable noise characteristics at this frequency and can produce high frequency instability in the GHz range that can leak into the measured frequency range, albeit down to tens of decibels. Because the gain of the system can preferably be >80dB overall, any small instabilities or inherent electrical noise can be amplified and signal integrity degraded.

Referring to fig. 6B, the RF-RX coil can be designed to image a particular limited field of view based on the targeted anatomical tissue. The prostate is for example approximately 60mm deep inside the human body (see fig. 6D), so in order to design an RX coil for prostate imaging, the coil should be configured to enable imaging at a depth of 60mm inside the human body. According to the Biot-Savart law, the magnetic field of the toroidal coil can be calculated by the following formula,

where μ 0 ═ 4 pi × 10-7H/m is the vacuum permeability, R is the radius of the toroidal coil, z is the distance from the center of the coil along the centerline of the coil, and I is the current on the coil (see fig. 6B). Assuming that I is 1 ampere, in the case of positioning the target of the map of the magnetic field (Bz) with z being 60mm, the maximum position is when R is 85mm according to the graph shown in fig. 6C.

Based on the geometric constraints of the body, a toroidal coil can be established in the space between the legs of a person on the torso. Thus, it is extremely difficult, although not impossible, to fit 170mm diameter coils there. According to FIG. 6C, when R is less than 85mm, the Bz field value is proportional to the radius of the loop. It is therefore advantageous that the coil is as large as it can. For example, the largest loop coil that can be placed between people is about 10 mm.

The magnetic field of a 10mm diameter coil is generally not able to reach the depth of the prostate due to the size of the coil being limited by the space between the legs. Thus, a single coil may not be sufficient for prostate imaging, so in this case, multiple coils prove advantageous in order to take signals from different directions. In various embodiments of an MRI system, the magnetic field is set in the z-direction and the RF coil is sensitive to the x-and y-directions. In this example case, the loop coil in the x-y plane cannot collect RF signals from a person because it is sensitive to the z-direction, in which case a butterfly coil can be used. Thus, based on position and orientation, the RF coil can be a loop coil or a butterfly coil. In addition, the coil can be placed under the body, and there is no limitation on its size.

As for the case where multiple RX coils are required, in various embodiments, decoupling between them can prove advantageous for various embodiments of the MRI system RX coil array. In those cases, each coil can be decoupled from the other coils, and the decoupling technique can include, for example: 1) geometric decoupling, 2) capacitive/inductive decoupling, and 3) low/high impedance preamplifier coupling.

According to various embodiments, the MRI system can have a varying magnetic field from the magnet, and its strength can vary linearly along the z-direction. The RX coils can be located at different positions in the z-direction and each coil can be tuned to a different frequency, which can depend on the position of the coils in the system.

Based on the simplicity of the individual loop coils, these coils can be made from simple conductive traces that can be pre-tuned to the desired frequency and can be printed, for example, on a disposable substrate. For a given procedure and subsequent coil handling, this inexpensive manufacturing technique can allow a clinician to place an RX coil (or coil array) on the body at a region of interest. For example, and in accordance with various embodiments, the RX coil can be a surface coil that can be attached (e.g., worn or adhered) to the body of a patient. For other body parts, such as the ankle or wrist, the surface coil may be in a single loop configuration, figure-8 configuration, or a butterfly coil configuration around the region of interest. For regions requiring significant penetration depth, such as the torso or knee, the coils may be comprised of Helmholtz (Helmholtz) coil pairs. The main limitations on the receive coil are similar to other MRI systems: the coils must be sensitive to planes orthogonal to the axis of the main magnetic field B0.

According to various embodiments, the coil may be inductively coupled to another loop that is electrically connected to the receive preamplifier. This design will allow easy and unimpeded access to the receiving coil.

According to various embodiments, the size of the coil can be limited by the structure of the human body. For example, the coil should be sized and configured to fit the space between the legs of a person when imaging the prostate.

It should be appreciated that any use of subheadings herein is for organizational purposes and should not be construed as limiting the application of those subheading features to the various embodiments herein. Each feature described herein may be applicable and usable in all of the various embodiments discussed herein, and all features described herein can be used in any desired combination, regardless of the particular example embodiments described herein. It should further be noted that the exemplary description of a particular feature is used primarily for informational purposes and is not intended to limit in any way the design, sub-features, and functionality of the specifically described feature.

Programmable logic controller

As discussed herein, and in accordance with various embodiments, various systems, and various combinations of features making up various system embodiments, can also include a Programmable Logic Controller (PLC). A PLC is an industrial digital computer that can be designed to operate reliably in harsh use environments and conditions. Not only in the enclosure, but also in the internal components and cooling configurations, the PLC can be designed to handle these types of conditions and environments. Thus, the PLC can be adapted to control various manufacturing processes, such as assembly lines, or robotic devices, or any activity requiring high reliability control and ease of programming and handling fault diagnostics.

According to various embodiments, a system can include a PLC capable of controlling the system in pseudo-real time. The controller is capable of managing power cycling and enabling of the gradient amplifier system, the radio frequency transmission (transmission) system, the frequency tuning system, and sending keep alive signals to the system watchdog (e.g., messages sent by one device to another, to check that the link between the two is operational, or to prevent the link from being broken). The system watchdog can continuously look for the strobe signal supplied by the computer system. If the computer thread is stopped, a strobe triggering the watchdog to enter a fault condition may be missed. The watchdog can be operated to power down the system if the watchdog enters a fault condition.

PLCs are typically capable of processing low level logic functions on incoming and outgoing signals into a system. The system is able to monitor subsystem health and control when a subsystem needs to be powered on or enabled. The PLC can be designed in different ways. One design example includes a PLC having one main motherboard with four expansion boards. Due to the speed of the microcontroller on the PLC, the subsystems can be managed in pseudo real-time, while real-time applications can be handled by the computer or spectrometer on the system.

The PLC can provide a number of functional responsibilities, including, for example: powering on/off the gradient amplifiers (discussed in more detail herein) and RF amplifiers (discussed in more detail herein), enabling/disabling the gradient amplifiers and RF amplifiers, setting digital and analog voltages for RF coil tuning, and gating the system watchdog.

As discussed above, it should be understood that any use of subheadings herein is for organizational purposes and should not be construed as limiting the application of those subheading features to the various embodiments herein. Each feature described herein may be applicable and usable in all of the various embodiments discussed herein, and all features described herein can be used in any desired combination, regardless of the particular example embodiments described herein. It should further be noted that the exemplary description of a particular feature is used primarily for informational purposes and is not intended to limit in any way the design, sub-features, and functionality of the specifically described feature.

Robot

As discussed herein, and in accordance with various embodiments, various systems, and various combinations of features making up various system embodiments, can also include robots.

In certain medical procedures, such as prostate biopsies, the patient will typically undergo lengthy procedures in an uncomfortably inclined position, which often includes remaining motionless during a particular body position throughout the procedure. In such long procedures, if a metallic ferromagnetic needle is used for biopsy with guidance from the MRI system, the needle may experience an attractive force from the strong magnet of the MRI system and may therefore be deflected from its path during the entire procedure. Even without the use of a magnetic needle, local field distortions can cause distortions in the magnetic resonance image, and thus the image quality around the needle can result in poor quality. To avoid such distortions, pneumatic robots with complex compressed air mechanisms have been designed to work in conjunction with conventional MRI systems. Even so, access to the target anatomy remains challenging due to the form factor of currently available MRI systems.

Various embodiments presented herein include an improved MRI system configured for guiding a medical procedure, including, for example, a robot-assisted, invasive medical procedure. The techniques, methods, and apparatus disclosed herein relate to guided robotic systems that use magnetic resonance imaging as a guide to automatically guide a robot (generally referred to herein as a "robotic system") in a medical procedure. According to various embodiments, the disclosed techniques combine a robotic system with magnetic resonance imaging as a guide. According to various embodiments, the robotic systems disclosed herein are combined with other suitable imaging techniques, such as ultrasound, X-ray, laser, or any other suitable diagnostic or imaging method.

It should be appreciated that any use of subheadings herein is for organizational purposes and should not be construed as limiting the application of those subheading features to the various embodiments herein. Each feature described herein may be applicable and usable in all of the various embodiments discussed herein, and all features described herein can be used in any desired combination, regardless of the particular example embodiments described herein. It should further be noted that the exemplary description of a particular feature is used primarily for informational purposes and is not intended to limit in any way the design, sub-features, and functionality of the specifically described feature.

Spectrometer

As discussed herein, and in accordance with various embodiments, various systems, and various combinations of features making up various system embodiments, can also include a spectrometer.

The spectrometer is operable to control all real-time signaling for generating the image. Which produces an RF transmit (RF-TX) waveform, a gradient waveform, a frequency tuning trigger pulse waveform, and a blanking bit waveform. These waveforms are then synchronized with the RF receiver (RF-RX) signal. The system is capable of generating frequency swept RF-TX pulses and phase cycled RF-TX pulses. The swept RF-TX pulse allows the non-uniform B1+ field (RF-TX field) to excite the sample volume more efficiently and effectively. It is also capable of digitizing multiple RF-RX channels with the current configuration set to four receiver channels. However, this system architecture allows easy system scaling up to increase the number of transmit and receive channels to a maximum of 32 transmit channels and 16 receive channels without having to change the basic hardware or software architecture.

The spectrometer can provide a number of functional responsibilities including, for example, generating and synchronizing RF-TX (discussed in more detail herein) waveforms, X-gradient waveforms, Y-gradient waveforms, blanked bit waveforms, frequency-tuned trigger pulse waveforms, and RF-RX windows, as well as, for example, using digitization and signal processing of the RF-RX data followed by quadrature demodulation followed by finite impulse response filter decimation such as, for example, decimation by a cascaded integrator-comb (CIC) filter.

The spectrometer can be designed in different ways. One design example includes a spectrometer with three main components: 1) designing a radio device (SDR 1) with first software operating with a basic RF-TX daughter card and a basic RF-RX daughter card; 2) designing a radio device (SDR 2) with a second software operating with the LFRF TX daughter card and the basic RF-RX daughter card; and 3) a clock distribution module (eight channel clock) capable of synchronizing the two devices.

SDR is a real-time communication device between transmitted and received MRI signals. They are capable of transmitting to computers over 10Gbit optical fiber using a small form factor pluggable plus transceiver (SFP +) communication protocol. This communication speed can allow generation of a waveform with high fidelity and reliability.

Each SDR can include a motherboard with an integrated Field Programmable Gate Array (FPGA), a digital-to-analog converter, an analog-to-digital converter, and four module sockets for integrating the different daughter cards. Each of these daughter cards can be used to change the frequency response of the associated TX or RX channel. According to various embodiments, the system can utilize many variant daughter cards, including, for example, a base RF version, as well as a Low Frequency (LF) RF version. The basic RF daughter card can be used to generate and measure RF signals. The LF RF version can be used to generate gradient, trigger and blank bit signals.

An eight channel clock (octaclock) can be used to synchronize a multi-channel SDR system to a common timing source while providing high accuracy time and frequency reference profiles. It can do so, for example, with 8-way time and frequency allocations (1PPS and 10 MHz). An example of an eight channel clock is the etus Octoclock CDA, which is capable of assigning a common clock to up to eight SDRs to ensure phase coherence between two or more SDR sources.

It should be appreciated that any use of subheadings herein is for organizational purposes and should not be construed as limiting the application of those subheading features to the various embodiments herein. Each feature described herein may be applicable and usable in all of the various embodiments discussed herein, and all features described herein can be used in any desired combination, regardless of the particular example embodiments described herein. It should further be noted that the exemplary description of a particular feature is used primarily for informational purposes and is not intended to limit in any way the design, sub-features, and functionality of the specifically described feature.

RF AMP/gradient AMP

As discussed herein, and in accordance with various embodiments, various systems, and various combinations of features making up various system embodiments, can also include a radio frequency amplifier (RF amplifier) and a gradient amplifier.

An RF amplifier is an electronic amplifier that is capable of converting a low power radio frequency signal to a higher power signal. In operation, the RF amplifier is capable of accepting signals at low amplitudes and providing up to 60dB of gain with a flat frequency response, for example. The amplifier is capable of accepting a three-phase AC input voltage and is capable of having a 10% maximum duty cycle. The amplifier can be gated by a 5V digital signal so that no harmful noise is generated when the MRI receives the signal.

In operation, the gradient amplifiers can increase the energy of the signals before they reach the gradient coils so that the field strength can be strong enough to produce a change in the main magnetic field for locating later received signals. The gradient amplifier can have two active amplification channels that can be controlled independently. Each channel is capable of sourcing current to either the X or Y channel, respectively. The third axis of spatial encoding is typically handled by permanent gradients in the main magnetic field (B0). With a varying combination of pulse sequences, the signals can be located in three dimensions and reconstructed to produce the object.

It should be appreciated that any use of subheadings herein is for organizational purposes and should not be construed as limiting the application of those subheading features to the various embodiments herein. Each feature described herein may be applicable and usable in all of the various embodiments discussed herein, and all features described herein can be used in any desired combination, regardless of the particular example embodiments described herein. It should further be noted that the exemplary description of a particular feature is used primarily for informational purposes and is not intended to limit in any way the design, sub-features, and functionality of the specifically described feature.

display/GUI

As discussed herein, and in accordance with various embodiments, various systems, and various combinations of features making up various system embodiments, can also include a display, for example, in the form of a Graphical User Interface (GUI). According to various embodiments, the GUI can take whatever form desired is necessary to convey the information necessary to run the magnetic resonance imaging process.

Moreover, it should be appreciated that the display may be embodied in one of many other forms, such as, for example, a rack-mounted computer, mainframe computer, server, client, desktop computer, laptop computer, tablet computer, handheld computing device (e.g., PDA, cell phone, smart phone, mini-laptop, etc.), clustered grid, netbook, embedded system, or any other type of special or general purpose display device as may be desirable or appropriate for a given application or environment.

A GUI is a system of interactive visual components for computer software. The GUI can display delivery information and represent objects of actions that the user can take. When a user interacts with an object, the object changes color, size, or visibility. The GUI objects include, for example, icons, cursors, and buttons. These graphical elements are sometimes enhanced with sound, or visual effects like transparency and shading.

The user can interact with the GUI using an input device that can include, for example, alphanumeric and other keys, a mouse, a trackball, or cursor direction keys for communicating direction information and command selections to the processor and for controlling cursor movement on the display. The input device may also be a display configured with touch screen input capabilities. The input device typically has two axes-two degrees of freedom in a first axis (i.e., x) and a second axis (i.e., y) -that allow the device to specify positions in a plane. However, it should be understood that input devices that allow 3-dimensional (x, y, and z) cursor movement are also contemplated herein.

According to various embodiments, a touchscreen or touchscreen monitor can serve as the primary human interface device that allows a user to interact with the MRI. The screen can have a projected capacitive touch sensitive display that includes an interactive virtual keyboard. The touch screen can have several functions including, for example, displaying a Graphical User Interface (GUI) to the user, relaying user input to the computer of the system, and starting or stopping scanning.

According to various embodiments, the GUI view can typically be a screen (Qt gadget) displayed to the user with appropriate buttons, edit fields, tabs, images, and so forth. These screens can be constructed using designer tools, such as, for example, Qt designer tools, to control the placement of the gadgets, their alignment, fonts, colors, and so forth. A User Interface (UI) sub-controller can possess modules configured to control the behavior (display and response) of the respective view module.

Several application utility (App utility) modules are capable of performing specific functions. For example, the S3 module enables data communication between an operating system and, for example, Amazon Web Services (AWS). Event filters can be presented to ensure that valid characters are displayed on the screen when user input is required. The dialog messages can be used to show various states, progress messages or to ask for user prompts. Furthermore, the system controller module can be utilized to handle coordination between the sub-controller modules and the main data processing blocks, pulse sequencer, pulse interpreter, spectrometer and reconstruction in the system.

It should be appreciated that any use of subheadings herein is for organizational purposes and should not be construed as limiting the application of those subheading features to the various embodiments herein. Each feature described herein may be applicable and usable in all of the various embodiments discussed herein, and all features described herein can be used in any desired combination, regardless of the particular example embodiments described herein. It should further be noted that the exemplary description of a particular feature is used primarily for informational purposes and is not intended to limit in any way the design, sub-features, and functionality of the specifically described feature.

Processing module

As discussed herein, and in accordance with various embodiments, various workflows or methods, and various combinations of steps making up the various workflow or method embodiments, can also include processing modules.

According to various embodiments, the processing module provides a number of functions. For example, the processing module is generally operable to receive signal data acquired during a scan, process the data, and reconstruct those signals to produce images that can be viewed (e.g., via a touch screen monitor that displays a GUI to a user), analyzed, and annotated by a system user. Typically, in order to generate an image, the NMR signals must be localized in three-dimensional space. Prior to or during RF acquisition, magnetic gradient coils localize the signals and are operated. By defining RF and gradient coil application sequences (called pulse sequences), the acquired signals correspond to a particular magnetic field and RF field arrangement. Arrays of these acquired signals can be reconstructed into images using mathematical operators and image reconstruction techniques. Typically, these images are generated from a simple linear combination of magnetic field gradients. According to various embodiments, the system is operable to reconstruct the acquired signals, for example, from a priori knowledge of the gradient fields, RF fields, and pulse sequences.

According to various embodiments, the processing module is also operable to compensate for patient displacement during the scanning process. Displacements (e.g. beating heart, breathing lungs, subject movements of the patient) are the most common sources of artifacts in MRI, and such artifacts affect image quality by causing misinterpretations in the images and subsequent loss of diagnostic quality. Thus, the displacement compensation protocol can help solve these problems at minimal cost in terms of temporal, spatial resolution, temporal resolution, and signal-to-noise ratio.

According to various embodiments, the processing module may include an artificial intelligence machine learning module designed to eliminate signal interference and improve image signal-to-noise ratio.

According to various embodiments, the processing module is also operable to assist a clinician in planning a path for a subsequent patient intervention procedure, such as a biopsy or the like. According to various embodiments, a robot can be provided as part of a system to perform an interventional procedure. The processing module can transmit instructions to the robot based on the image analysis to properly access the appropriate region of the body, for example, requiring a biopsy.

It should be appreciated that any use of subheadings herein is for organizational purposes and should not be construed as limiting the application of those subheading features to the various embodiments herein. Each feature described herein may be applicable and usable in all of the various embodiments discussed herein, and all features described herein can be used in any desired combination, regardless of the particular example embodiments described herein. It should further be noted that the exemplary description of a particular feature is used primarily for informational purposes and is not intended to limit in any way the design, sub-features, and functionality of the specifically described feature.

Chirp magnetic resonance imaging module

For wide bandwidth pulses, two well-recognized ways to increase the bandwidth of a Radio Frequency (RF) pulse beyond the limits of the fourier relationship between its length and bandwidth are composite pulses and adiabatic pulses. In particular, adiabatic pulses can be used for imaging, with typical goals of compensating for RF field imperfections and compensating for permanent magnetic field gradients. An example of an adiabatic pulse of interest is a chirped pulse. A known use of chirped pulses is to encode spatial information using permanent gradients as well as pulsed electromagnetic gradients.

The disclosed systems and methods according to various embodiments as described herein relate to an improved way of collecting NMR spectra and MR images in inhomogeneous fields via RF chirped pulses using wide bandwidth pulses.

For multi-slice excitation methods for imaging non-uniform fields, there are methods for collecting information from the entire imaging volume if the bandwidth of the RF pulses cannot be increased (e.g., via a wide-band pulse) or should not be increased. A related way is to tune the resonance frequency of the RF coil to different frequencies when a user wants to measure different parts of the space. This allows one to sample the entire imaging field of view even when the bandwidth of the RF pulse is narrower than the frequency range of the entire field of view. As a result of this multi-slice excitation approach, one can image a three-dimensional (3D) volume by exciting multiple slices along one axis, and then phase encoding along the other two axes. Using a readout pulse in a system with a strong permanent gradient is not appropriate because the axis of readout will be tilted by the permanent gradient. The problem with such techniques is that each slice must be measured one at a time and the thinness of each slice results in a neglect of the slice selection axis, thus resulting in a projection of the 3D voxels onto the 2D plane, with the axes of the 2D plane phase encoded. Thus, having to phase encode both axes while also collecting each slice one by one severely slows down the rate of image acquisition.

The disclosed systems and methods according to various embodiments as described herein relate to an improved way of collecting NMR spectra and MR images in inhomogeneous fields using multi-slice excitation methods at faster image acquisition rates than currently present in the prior art.

According to various embodiments, the non-uniformity may be considered as a degree of lack of uniformity, such as a slight deviation of the local magnetic field from the mean value of the field.

According to various embodiments, the pulse sequence diagram illustrates steps of basic hardware activity that are incorporated into the pulse sequence using a plurality of lines, each line representing a different component. For example, the radio frequency transmitter components can be represented on the top line of the pulse sequence diagram, the slice selection gradient can be represented on the second line, the phase encoding gradient can be represented on the third line, and the frequency encoding/readout gradient can be represented on the fourth or bottom line.

Fig. 7A is an example schematic pulse sequence diagram 700a of a two-dimensional (2D) pulse sequence in accordance with various embodiments. For the pulse sequence diagram of the 2D pulse sequence, as shown in fig. 7A, the slice selection and signal detection are repeated in duration, relative timing, and amplitude each time the sequence is repeated. The duration of the slice selection pulse may range from 70 microseconds to 10 milliseconds, while the amplitude of the slice selection pulse may be modified to reach a flip angle of 1 to 180 degrees. The duration of the acquisition window will vary depending on the strength of the readout gradient applied during it. The acquisition duration may range from 10 microseconds to 10 milliseconds, with the number of points acquired at that time ranging from 16 to 512. For each sequence performed, a single phase encoded component is presented. Deviations above or below the horizontal line are generally indicative of gradient pulses. The pulse map can indicate simultaneous component activity, such as RF pulses and slice selection gradients, at the same horizontal position as a non-zero deviation from the two lines. A simple deviation from zero shows a constant amplitude gradient pulse. The gradient amplitudes, which change during the measurement, for example the phase encoding, are represented on the figure.

Fig. 7B is an example schematic pulse sequence diagram 700B of a three-dimensional pulse sequence in accordance with various embodiments. As illustrated in fig. 7B, the illustrated 3D pulse sequence 700B includes volume excitation and signal detection that are repeated in duration, relative timing, and amplitude each time the sequence is repeated. In the case of a 3D pulse sequence, two-phase encoding components are present each time the sequence is executed, one in the phase encoding direction and the other in the slice selection direction (irrespective of the increment of the amplitude).

It is well known that in Magnetic Resonance Imaging (MRI) inhomogeneities of the static magnetic field, e.g. a permanent gradient field (which is also referred to herein as non-uniform permanent gradient field), generated by the scanner and by the subject sensitivity are difficult to avoid. Typically, field inhomogeneity is a nuisance to avoid, and inhomogeneous fields are rarely sources of spatial information. Large values of gyromagnetic coefficients can cause significant frequency shifts in even parts per million field inhomogeneities, which in turn cause distortions in both the geometry and intensity of the Magnetic Resonance (MR) image. Manufacturers will always strive to make the magnetic field uniform, especially at the heart of the scanner. Even with perfect magnets, the non-uniformity is still present to some extent, which may be caused by the sensitivity of the imaging subject. For example, for certain situations, such as stereotactic surgery, geometric distortion (shift in pixel position) is important. A second problem is an undesired change in the intensity or brightness of the pixels, which may cause problems in determining different tissues and reduce the maximum available image resolution.

Related methods for imaging in non-uniform fields include the use of wide bandwidth pulses and multi-slice excitation. However, both address the challenges of imaging in non-uniform permanent fields. A wide bandwidth pulse, for example, affects a wide range of frequencies. The bandwidth of the wide bandwidth pulse may range from about 1kHz to about 1 MHz. According to various embodiments, the bandwidth may range from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, and 400kHz to 1MHz, or any range of bandwidths thereof. Examples of RF pulses that can have such a bandwidth include chirped pulses, adiabatic half-pass pulses, and composite intense pulses. If the field is non-uniform, increasing the bandwidth of the pulse means that the RF pulse can affect more samples. There are many ways to increase the bandwidth of an RF pulse beyond the limit of the fourier relationship between its length and bandwidth. Two notable approaches are composite pulses and adiabatic pulses.

Composite pulses are conventional RF pulses that are added to each other in a sequence, with often a phase shift between the added pulses. By combining the RF pulses in this way, their imperfections can be compensated. This also makes the bandwidth of the composite pulse larger than the bandwidth of the pulse used to generate it. This makes the composite pulse ideal for use in non-uniform magnetic fields.

Adiabatic pulses excite, invert, or refocus the magnetization by different means than conventional RF pulses. Adiabatic pulses gradually change the effective field, dragging the magnetization with the field as it changes, rather than abruptly changing the effective magnetic field experienced by the magnetization. The effective field is changed by changing the frequency of the RF pulses. The duration of these pulses can range from 100 microseconds to 20 milliseconds. The magnetization will tend to align with the direction of the effective field until the RF pulse resonates with the magnetization, wherein adiabatic conditions will be violated, allowing adiabatic excitation. In the case of adiabatic inversion, the magnetization will always be behind the direction of the effective field. This allows, among other advantages, the RF pulses to have a much wider bandwidth than conventional RF pulses. One can implement adiabatic pulsing to excite wide bandwidths in oil logging because oil logging can occur in inhomogeneous fields. One can also implement adiabatic pulsing in imaging, usually to compensate for RF field imperfections, but also for permanent magnetic field gradients.

One example of the use of adiabatic pulses to compensate for permanent gradients is the multi-scan extension of cross term space-time encoding (xspan), using pulse sequences of the type of adiabatic pulses known as chirps. A chirped pulse is one in which different wavelengths or colors are not uniformly distributed over the temporal envelope of the pulse. Thus, the pulse affects different parts of the space at different times, producing signals that are refocused at different points along the acquisition. Exploiting these characteristics of chirped pulses can allow spatial information to be encoded using both permanent and pulse gradients.

For multi-slice excitation methods for imaging non-uniform fields, there are methods for collecting information from the entire imaging volume if the bandwidth of the RF pulse cannot be increased or should not be increased (e.g., via a broadband pulse). A related way is to tune the resonance frequency of the RF coil to different frequencies when a user wants to measure different parts of the space. This allows one to sample the entire imaging field of view even when the bandwidth of the RF pulse is narrower than the frequency range of the entire field of view. As a result of the multi-slice excitation method, one can image a 3D volume by exciting multiple slices along one axis and then phase-encoding along the other two axes, which is necessary for phase-encoding along both axes due to the strong gradients present in the magnetic field that are typically produced by such multi-slice excitation methods. Phase encoding along two axes is performed by applying magnetic field gradients along two orthogonal axes when no signal is acquired. By arranging the gradient strength or duration during this phase encoding step, the image can be encoded along two additional dimensions, while the third axis is encoded during the signal acquisition step. The problem with this technique is that each slice must be measured one at a time and the thinness of each slice results in a neglect of the slice selection axis, thus resulting in a projection of the 3D voxels onto the 2D plane, where the axes of the 2D plane are phase encoded. Thus, having to phase encode both axes while also collecting each slice one by one severely slows down the rate of image acquisition.

According to various embodiments, the techniques described herein relate to collecting NMR spectra and MR images in a non-uniform field using a multi-slice excitation method at faster image acquisition rates than current prior art techniques. Thus, applicants have recognized that implementing wide bandwidth pulses (e.g., adiabatic pulses) with chirped pulses lacks a solution for scanner types that attempt to avoid encoding the necessary spatial information with pulse gradients. Applicants have further recognized that there is a lack of solution for implementing multi-slice excitation methods in scanners that result in faster rates of image acquisition compared to current prior art.

If the permanent gradients in a single-sided MRI can be made linear or at least bijective (e.g., one-to-one correspondence between data sets), then information from the gradients can be used to encode spatial information. In order to use a permanent gradient as an encoding gradient, the spin echo must be acquired in the field generated by this gradient. A fourier transform or non-linear reconstruction of the time domain data of the spin echoes can then be used to generate a 1-dimensional distribution map of the object or patient along the direction of the gradient of the permanent field. For it to be useful, a significant part of the magnetization within the gradient must be accessible for the RF pulse.

According to various embodiments, a scanner is provided that has a permanent gradient, in particular optimized using small magnetic elements arranged in a pattern to produce a gradient that is weak enough to allow wide RF bandwidth excitation up to about 200kHz, but strong enough for spatial encoding in the direction of the permanent magnet. The scanner can also have an RF coil with multiple legs to increase the overall field strength, which allows strong and uniform excitation over a wide bandwidth with adiabatic pulses. This allows for the use of a unique MRI pulse sequence for 3D encoding by promaxxol (Promaxo).

The basis of the pulse sequence used according to the various embodiments herein is that the permanent slice selection gradient also serves as readout gradient. In other words, the information about the slice axis is not projected onto the 2D plane. This is advantageous especially for scanners that use mostly permanent gradients, since the pulsed readout gradient will most likely distort the image. For good image fidelity, axes other than the slice selection axis must be phase encoded.

There are many ways to implement a pulse sequence according to various embodiments herein. These include the use of wide bandwidth pulses via adiabatic pulses such as, for example, chirped pulses, for excitation and refocusing. Chirped pulses can be used, for example, to increase bandwidth. By using chirped pulses, for example, a wide bandwidth can be excited and frequencies within the bandwidth can contain spatial information along one axis.

Fig. 8 is a schematic pulse sequence diagram 800 of a system utilizing chirped pulses and permanent slice selection gradients, in accordance with various embodiments. As illustrated in fig. 8, in accordance with various embodiments, an approach is provided for using a wide-band pulse (e.g., chirped pulse) for collecting magnetic resonance images or spectra using single-sided MRI. For example, if a permanent magnetic gradient field, such as a non-uniform magnetic field, is along the axis in the z-direction, two-stage encoding 810 and 820 can be used in the x and y axes, as shown in pulse diagram 800. In the example illustrated in fig. 8, a single echo can be used. In addition, the pulse pattern 800 includes two chirped pulses 830 and 840, which two chirped pulses 830 and 840 can be used and calibrated such that during acquisition 850 all magnetizations are refocused simultaneously (e.g., at precise time periods). Thus, according to various embodiments, if both pulses have the same or substantially similar bandwidth, the second pulse 840 can be half the length of the first pulse 830 as illustrated in the pulse diagram 800.

The bandwidth of these pulses may range from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, and 400kHz to 1MHz, or any range of bandwidth thereof. The magnetization affected by the chirped pulse can be, for example, phase encoding along two orthogonal axes or only along one axis for a 2D image. In various embodiments, the entire imaging volume is encoded simultaneously. In various embodiments, multiple portions of the imaging volume are encoded one at a time. The resulting signal is encoded along z for readout and x and y for phase encoding. This allows one to image the entire volume more quickly. The slice thickness of the volume can be increased with post-processing to improve the signal-to-noise ratio.

Thus, in view of the above, applicants have discovered a way to collect NMR spectra and MR images in non-uniform fields, without the need for pulse gradients, with faster image acquisition rates, in combination with multi-slice excitation methods in certain MRI scanners (e.g., single-sided MRI), using certain broadband pulses (e.g., chirped pulses). This method allows imaging of an entire volume more quickly than would otherwise be possible with multi-slice acquisition. Furthermore, by using the slice selection gradient as readout, no information along the z-axis is lost. Considering the techniques disclosed in accordance with various embodiments, the disclosed implementation approaches overcome existing challenges when combining two approaches. For example, some of the challenges overcome may include the following difficulties: implementing chirped pulses for imaging while compensating for their anomalous behavior, designing a permanent field that can be used for imaging, interleaving data slices excited by the chirped pulses for efficient signal averaging, and/or efficiently reducing 3-dimensional data to a series of 2-dimensional slices when measuring the third dimension directly.

Acceleration can be best evaluated by calculating how many slices are needed to image the normal field of view. For example, according to various embodiments, the field of view (also referred to herein as the region of interest) in the scanners discussed herein is a 4 to 12 inch diameter sphere. An example scanner is capable of generating conventional slice selection pulses with a thickness ranging from 0.5 to 5mm, which means that, for example, approximately 34 slices will be selected to cover the entire field of view. The same scanner can also produce chirped pulses that excite slices with a thickness of 1 inch, meaning that only four slices are needed to cover the entire field of view, as long as the slice direction is also treated as readout. In the case of possible limitations on acceleration due primarily to the hardware of the scanner, this would be an acceleration of approximately 8.5. With a wide bandwidth receive and transmit coil equal to the bandwidth of the field of view, the entire imaging volume can be selected with one slice.

Fig. 9 illustrates an example pulse sequence in accordance with various embodiments. As illustrated in fig. 9, are some examples of digital waveforms generated by a system computer and transmitted to a software-designed radio (SDR). The signal sequence 910 shown in the top channel is a radio frequency transmit (RF TX) channel having all waveforms sent to the transmit system (TX) segment of the RF system. In this example, all pulses in the rf tx channel are chirped pulses having the same bandwidth but different durations. According to various embodiments, the generated pulses are not mixed with the carrier in this iteration, meaning that their center frequency is 0 Hz. According to various embodiments, once generated, the pulses are mixed with the carrier in the SDR, changing their center frequency to the frequency needed to meet the Larmor (Larmor) frequency of the system.

As illustrated in fig. 9, signal sequence 920 is a radio frequency receive (RFRx) channel. Unlike the rf tx channel, this channel is not converted to an analog signal. Rather, when the SDR is to digitize an analog signal that it receives from the receive system (RX) portion of the RF system, that channel is a series of instructions for the SDR. According to various embodiments, the SDR always receives some signal from the RX part, but the signal collected is only relevant for imaging when the RFRx channel is set to 1.

Further illustrated in fig. 9, the signal sequences 930 and 940 shown in the lower two channels are gradient channels. According to various embodiments, these signal sequences 930 and 940 correspond to waveforms that are sent to the gradient coils after being amplified by the gradient amplifiers. According to various embodiments, the gradient is responsible for encoding spatial information in the collected signal.

Figure 10 illustrates example positions of a patient for imaging in a magnetic resonance imaging system 1000, in accordance with various embodiments. As illustrated in fig. 10, a receive (Rx) coil 1070 can be located on the patient 1100. According to various embodiments, the receive coil 1070 can be one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration. As illustrated in fig. 10, the receive coil 1070 is a 3-loop coil placed over the anatomical portion of the patient 1100. According to various embodiments, the signals acquired by the receive coil 1070 can be transmitted to the RX part of the RF system.

According to various embodiments, a method for performing a chirped MRI scan includes the following steps. In a first step, the patient is positioned such that the relevant part of their body is placed in the field of view. The receive coil or coil array is then placed on the patient. Different parts of the body can require different receive coil arrays. The design of these arrays varies according to various embodiments. According to various embodiments, some designs have all coils have the same tuning, which varies with the tuning frame. Other designs have arrays of coils with each coil having a separate static tuning, according to various embodiments. Regardless of design, the receive coils are placed so that their spatial sensitivity overlaps with the frequencies to which they are sensitive. Once the patient and the receive coils are positioned, signals are acquired to confirm their placement. The signal is acquired by sending two pulses from the SDR to the TX part of the RF system. Both of these pulses are chirped pulses designed to induce a signal in the patient that will be picked up by a receiving coil located on their body. These signals are then transmitted from the receive coils to the RX part of the RF system. If a signal is detected, the scanning continues to its next step. In the next stage, images of the patient are taken to confirm that they have been placed in the correct position. To collect the images, a sequence of chirped pulses is applied to the patient. These pulses are sent out by the TX part of the RF system. Between the application of these chirps, signals are acquired from the receive coils by the RX part of the RF system. Also, gradient pulses are sent to the system to encode spatial information into a signal. Once the position of the patient is confirmed, a complete image is acquired. The full image is collected in a manner similar to the image used to confirm the position of the patient. The only difference is that the complete image will be of higher resolution and will therefore take longer to acquire.

According to various embodiments, a magnetic resonance imaging system is provided. According to various embodiments, a system includes a radio frequency receive system including a radio frequency receive coil configured to be placed in proximity to a target subject. According to various embodiments, the receiving system is configured to deliver a signal of the target subject for forming a magnetic resonance image of the target subject, wherein the signal comprises at least two chirped pulses. According to various embodiments, the system comprises a housing, wherein the housing comprises permanent magnets for providing the non-uniform permanent gradient field. According to various embodiments, the imaging system is configured to apply multi-slice excitation along the non-uniform permanent gradient field, the radio frequency transmit system is configured to deliver a sequence of chirped pulses, and the single-sided gradient coil set is configured to deliver a plurality of gradient pulses orthogonal to the non-uniform permanent gradient field.

According to various embodiments, the system further comprises a power supply, wherein the power supply is configured to flow a current through at least one of the radio frequency transmission system and the single-sided gradient coil set to generate an electromagnetic field in a region of interest, wherein the region of interest surrounds the target body. According to various embodiments, the region of interest has a diameter of 4 to 12 inches.

According to various embodiments, the imaging system is configured to apply a multi-slice excitation comprising exciting a plurality of slices along an axis of the non-uniform permanent gradient field, wherein each of the plurality of slices has a bandwidth of a wide bandwidth similar to a chirped pulse. According to various embodiments, the chirped pulses comprise the same bandwidth and different durations. According to various embodiments, the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

According to various embodiments, the chirped pulses are configured to produce a 1-dimensional signal along an axis of the non-uniform permanent gradient field. According to various embodiments, the 1-dimensional signal is a first 1-dimensional signal, the gradient pulses are configured to generate a second 1-dimensional signal and a third 1-dimensional signal that are orthogonal to each other and to an axis of the non-uniform permanent gradient field.

According to various embodiments, the gradient pulses are configured for encoding spatial information into a signal. According to various embodiments, a combination of non-uniform permanent gradient fields and chirped pulses is configured for slice selection in non-uniform permanent gradients and frequency encoding gradients. According to various embodiments, the target subject is an anatomical part of the body.

According to various embodiments, the receive coil comprises an array of receive coils, and each of the array of receive coils is configured for a particular anatomical part of the body. According to various embodiments, the chirped pulses induce a signal in the target body, and the receive coil is configured to receive the signal. According to various embodiments, each of the at least two chirped pulses is split into two components that are 90 degrees out of phase. According to various embodiments, the transmission system further comprises two separate ports configured to generate the at least two chirped pulses.

According to various embodiments, the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with a blanking signal. According to various embodiments, the magnetic resonance imaging system further comprises a radio frequency amplifier that is enabled and disabled when the control system is turned on and off with the blanking signal.

According to various embodiments, a radio frequency transmission system includes a transmission coil that is non-planar and positioned to partially surround a region of interest.

According to various embodiments, the magnetic resonance imaging system further comprises a tuning block, wherein the tuning block is configured to change the frequency response of the transmit coil.

According to various embodiments, the gradient coil set is non-planar and positioned to partially surround the region of interest, and wherein the gradient coil set is configured to project magnetic field gradients to the region of interest.

According to various embodiments, the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within a region of interest.

According to various embodiments, the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the receive coil is smaller than the region of interest. According to various embodiments, the transmit coil and the gradient coil set are concentric with respect to the region of interest.

Figure 11 is a schematic illustration of an example magnetic resonance imaging system 1100 in accordance with various embodiments. The system 1100 includes an imaging system 1110, a power supply 1180, and a control system 1190. As shown in fig. 11, imaging system 1110 includes a housing 1120 and a radio frequency receive system 1170. As shown in fig. 11, the housing 1120 includes a permanent magnet 1130, a radio frequency transmission system 1140, a gradient coil assembly 1150, and an optional electromagnet 1160. According to various embodiments, the system 1100 can include various electronic components such as, but not limited to, varactors, PIN diodes, capacitors or switches (including micro-electro-mechanical system (MEMS) switches), solid state relays, or mechanical relays. The various electronic components listed above can be configured with the radio frequency transmission system 1140 according to various embodiments.

According to various embodiments, the example system 1100 shown and described as described with reference to fig. 11 is similar to, or includes similar components of the example system 100 shown and described as described with reference to fig. 1, so each component will not be described in greater detail unless specifically noted. For example, the radio frequency transmit system 1140 can comprise a radio frequency transmit coil that can be the same or substantially the same as the radio frequency transmit coil 140, in accordance with various embodiments. Similarly, according to various embodiments, the radio frequency receive system 1170 can include a radio frequency receive coil that can be the same or substantially the same as the radio frequency receive coil 170.

It should be appreciated that any use of subheadings herein is for organizational purposes and should not be construed as limiting the application of those subheading features to the various embodiments herein. Each feature described herein may be applicable and usable in all of the various embodiments discussed herein, and all features described herein can be used in any desired combination, regardless of the particular example embodiments described herein. It should further be noted that the exemplary description of a particular feature is used primarily for informational purposes and is not intended to limit in any way the design, sub-features, and functionality of the specifically described feature.

Figure 12 is a schematic illustration of an example magnetic resonance imaging system 1200 in accordance with various embodiments. As shown in fig. 12, the imaging system 1200 includes an imaging system 1210 and a control system 1290. Imaging system 1210 includes a radio frequency transmit system (RF-TX)1240, a radio frequency receive system (RF-RX)1270, a tuning block 1212, and a signal conditioning block 1214. Control system 1290 includes a Software Designed Radio (SDR)1292 and a control and interface system 1294. According to various embodiments, each of the various components of the system 1200 is communicatively coupled to other components of the system 1200.

The various arrows shown in fig. 12 illustrate the interconnection of the various components in the system 1200 and the workflow thereof, in accordance with various embodiments. For example, the workflow can begin with a computer residing within the control and interface system 1294. An example workflow includes the computation of digital waveforms that are needed and are computed in a particular order in which they need to be applied. The digital waveform is then sent to the SDR 1292, which SDR 1292 generates an analog waveform that is sent to the radio frequency transmission system 1240, which radio frequency transmission system 1240 includes a radio frequency amplifier and a transmit coil. This amplifies the waveform produced by the SDR 1292 and sends it out into the target subject (e.g., body, patient, or phantom). The attributes of the system are adjusted using a signal adjustment block 1214 that turns the imaging system 1210 on and off using a blanking signal and a tuning block 1212 that adjusts the frequency response of the system. According to various embodiments, the tuning block 1212 is an optional component in the imaging system 1210.

Upon receiving the waveform, the radio frequency transmission system 1240 induces spins in the target subject to generate signals that are detected by the radio frequency reception system 1270. The blanking and tuning signals are also utilized to activate and operate the radio frequency receiving system 1270. Like the transmitting system 1240, the receiving system 1270 does not necessarily require a tuning signal. Once activated and after receiving the signal, the receiving system 1270 sends a signal to the imaging system 1210 where the signal is digitized.

As shown in fig. 12, the signal conditioning block is configured to set the control signals sent to the various components of the system 1200 to the values that those components will accept. According to various embodiments, in order to activate the RF amplifier, it requires a higher voltage signal than SDR 1292 can generate. In such instances, the SDR 1292 can be configured to send a signal to the signal conditioning block 1214, which signal conditioning block 1214 then amplifies the signal to a level that the RF amplifier will recognize.

It should be appreciated that any use of subheadings herein is for organizational purposes and should not be construed as limiting the application of those subheading features to the various embodiments herein. Each feature described herein may be applicable and usable in all of the various embodiments discussed herein, and all features described herein can be used in any desired combination, regardless of the particular example embodiments described herein. It should further be noted that the exemplary description of a particular feature is used primarily for informational purposes and is not intended to limit in any way the design, sub-features, and functionality of the specifically described feature.

Figure 13 is a schematic illustration of an example magnetic resonance imaging system 1300 in accordance with various embodiments. As shown in fig. 13, the imaging system 1300 includes an imaging system 1310 and a control system 1390. The imaging system 1310 includes a radio frequency transmit system 1340, a tuning block 1312, and a signal conditioning block 1314. The control system 1390 includes SDR 1392 and control and interface system 1394. As shown in fig. 13, the radio frequency transmit system 1340 includes a radio frequency power amplifier 1342, a radio frequency combiner 1344, a transformer (such as a balun) 1346, and a radio frequency transmit coil 1348. According to various embodiments, each of the various components of system 1300 is communicatively coupled to the other components of system 1300.

The various arrows shown in fig. 13 illustrate the interconnection of the various components in the system 1300 and the workflow thereof, according to various embodiments. For example, the workflow can begin with a computer residing within the control and interface system 1394. An example workflow includes when an analog waveform is generated in the SDR 1392 and sent to the radio frequency power amplifier 1342. According to various embodiments, the generated waveform can be a chirp waveform. A control signal is also sent to the amplifier 1342 to turn on and enable the amplifier 1342 only when the SDR 1392 issues a transmit pulse. According to various embodiments, the waveform is amplified and sent to a radio frequency combiner 1344, which radio frequency combiner 1344 splits the wave into two waves that are 90 degrees out of phase. According to various embodiments, the wave is not split into two waves that are 90 degrees out of phase, but instead can be sent directly to a single port of the transmit coil 1348. These waves are sent to two ports of a transmit coil 1348, which transmit coil 1348 then produces an RF pulse that generates a signal that is detected by a receive system, such as the receive system 1170 or 1270. According to various embodiments, the waves are transmitted to the transmit coil 1348 via a transducer 1346. According to various embodiments, the system is controlled by a tuning block 1312 that changes the frequency response of the transmit coil 1348 and a signal adjustment block 1314 that enables and disables the amplifier 1342. According to various embodiments, in the in-imaging system 1310, the tuning block 1312 and the transformer or balun 1346 are optional components.

It should be appreciated that any use of subheadings herein is for organizational purposes and should not be construed as limiting the application of those subheading features to the various embodiments herein. Each feature described herein may be applicable and usable in all of the various embodiments discussed herein, and all features described herein can be used in any desired combination, regardless of the particular example embodiments described herein. It should further be noted that the exemplary description of a particular feature is used primarily for informational purposes and is not intended to limit in any way the design, sub-features, and functionality of the specifically described feature.

Fig. 14 is a schematic illustration of an example imaging system 1400, in accordance with various embodiments. As shown in fig. 14, the imaging system 1400 includes an imaging system 1410 and a control system 1490. The control system 1490 includes a control and interface system 1494. Imaging system 1410 includes a radio frequency receiving system 1470 and a tuner block 1412. As shown in fig. 14, the rf receive system 1470 includes an rf receive coil 1472, a first stage preamplifier 1474, a transformer (such as a balun) 1476, and a second stage preamplifier 1478. According to various embodiments, each of the various components of the system 1400 is communicatively coupled to the other components of the system 1400.

The various arrows shown in fig. 14 illustrate the interconnection of the various components in the system 1400 and the workflow thereof, in accordance with various embodiments. For example, the workflow can begin with a computer residing within the control and interface system 1494. An example workflow includes when a radio frequency signal generated by a target subject is detected at the receiving system 1470. These signals are induced by a transmission system, such as transmission systems 1140, 1240, or 1340. According to various embodiments, tuning block 1412 is configured to set the frequency to which receive coil 1472 is sensitive. When the frequency to which receive coil 1472 is tuned detects or receives signals at receive coil 1472, their signals are sent to a first stage preamplifier 1474, which first stage preamplifier 1474 amplifies the received signals. According to various embodiments, the system 1400 becomes less susceptible to noise through amplification by the first stage preamplifier 1474. The amplified signal is then sent through transformer 1476 and to another amplification stage at a second stage preamplifier 1478 to further improve the signal's resistance to noise. From the second stage, the now fully amplified signal is sent to the control and interface system 1494, where it is digitized and processed at the control and interface system 1494. The amount of coils may vary depending on the application.

It should be appreciated that any use of subheadings herein is for organizational purposes and should not be construed as limiting the application of those subheading features to the various embodiments herein. Each feature described herein may be applicable and usable in all of the various embodiments discussed herein, and all features described herein can be used in any desired combination, regardless of the particular example embodiments described herein. It should further be noted that the exemplary description of a particular feature is used primarily for informational purposes and is not intended to limit in any way the design, sub-features, and functionality of the specifically described feature.

Workflow embodiment

In accordance with various embodiments, various systems are disclosed herein, as well as various combinations of features of the various system components and embodiments that make up the disclosed magnetic resonance imaging system.

Figure 15 is a flow diagram of a method S100 for performing magnetic resonance imaging, in accordance with various embodiments. The method S100 comprises providing a magnetic resonance imaging system at step S110. The system comprises: the system comprises a radio frequency receiving system and a shell, wherein the shell comprises a permanent magnet for providing a non-uniform permanent gradient field, a radio frequency transmitting system and a single-sided gradient coil set.

As shown in fig. 15, the method S100 includes: in step S120, the receiving coil is placed close to the target subject. The method S100 includes: in step S130, a sequence of chirped pulses is applied via the transmit system.

As shown in fig. 15, the method S100 includes: in step S140, a multi-slice excitation is applied along the non-uniform permanent gradient field. The method S100 includes: in step S150, a plurality of gradient pulses are applied via a gradient coil set orthogonal to the non-uniform permanent gradient field.

As shown in fig. 15, the method S100 includes: in step S160, a signal of the target subject is acquired via the receiving system, wherein the signal includes at least two chirps. The method S100 includes: in step S170, a magnetic resonance image of the target subject is formed.

According to various embodiments, the application of chirped pulses, multi-slice excitation, and gradient pulses are timed such that the magnetization refocuses each time the receiving system acquires a signal. According to various embodiments, the system additionally includes a power supply, wherein the power supply is configured to flow a current through at least one of the radio frequency transmit coil and the set of single-sided gradient coils to generate an electromagnetic field in a region of interest, wherein the region of interest surrounds the target body. According to various embodiments, the region of interest has a diameter of 4 to 12 inches.

According to various embodiments, the multi-slice excitation includes exciting a plurality of slices along an axis of the non-uniform permanent gradient field, wherein each of the plurality of slices has a bandwidth of a wide bandwidth similar to a chirped pulse. According to various embodiments, the chirped pulses comprise the same bandwidth and different durations. According to various embodiments, the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

According to various embodiments, the chirped pulses are configured to produce a 1-dimensional signal along an axis of the non-uniform permanent gradient field. According to various embodiments, the 1-dimensional signal is a first 1-dimensional signal, the gradient pulses are configured to generate a second 1-dimensional signal and a third 1-dimensional signal that are orthogonal to each other and to an axis of the non-uniform permanent gradient field.

According to various embodiments, the gradient pulses are configured for encoding spatial information into a signal. According to various embodiments, a combination of non-uniform permanent gradient fields and chirped pulses is configured for slice selection in non-uniform permanent gradients and frequency encoding gradients.

According to various embodiments, the target subject is an anatomical part of the body. According to various embodiments, the receive coil comprises an array of receive coils, and each of the array of receive coils is configured for a particular anatomical part of the body.

According to various embodiments, the chirped pulses induce a signal in the target body, and the signal is received by the receive coil. According to various embodiments, each of the at least two chirped pulses is split into two components that are 90 degrees out of phase. According to various embodiments, each of the at least two chirps is split into two components, which are sent to two separate ports of the transmission system.

According to various embodiments, the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with a blanking signal. According to various embodiments, a blanking signal is utilized to turn the system on and off to enable and disable, respectively, the radio frequency amplifier.

According to various embodiments, a radio frequency transmission system includes a transmission coil that is non-planar and positioned to partially surround a region of interest. According to various embodiments, the magnetic resonance imaging system further comprises a tuning block, wherein the tuning block is configured to change the frequency response of the transmit coil.

According to various embodiments, the gradient coil set is non-planar and positioned to partially surround the region of interest, and wherein the gradient coil set is configured to project magnetic field gradients to the region of interest. According to various embodiments, the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within a region of interest. According to various embodiments, the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the receive coil is smaller than the region of interest.

According to various embodiments, the transmit coil and the gradient coil set are concentric with respect to the region of interest.

Figure 16 is a flow diagram of a method S200 for performing magnetic resonance imaging, in accordance with various embodiments. The method S200 includes providing an imaging system at step S210. The system includes a radio frequency receive coil and a permanent magnet for providing a permanent gradient field.

As shown in fig. 16, the method S200 includes: in step S220, the receiving coil is placed close to the target subject. The method S200 includes: in step S230, a sequence of chirped pulses having a wide bandwidth is applied.

As shown in fig. 16, the method S200 includes: at step S240, a multi-slice excitation is applied along the permanent gradient field, wherein the multi-slice excitation includes exciting a plurality of slices along an axis of the permanent gradient field, wherein each of the plurality of slices has a bandwidth of a wide bandwidth similar to that of the chirped pulse.

As shown in fig. 16, the method S200 includes: in step S250, the phase encoding field is applied along two orthogonal directions perpendicular to the axis of the permanent gradient field. The method S200 includes: in step S260, a magnetic resonance image of the target subject is acquired.

According to various embodiments, the application of chirped pulses, multi-slice excitation, and gradient pulses are timed such that each magnetization refocuses as the signal is acquired. According to various embodiments, each magnetization is focused in a region of interest, wherein the region of interest surrounds the target subject. According to various embodiments, the region of interest has a diameter of 4 to 12 inches.

According to various embodiments, the chirped pulses comprise the same bandwidth and different durations. According to various embodiments, the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

According to various embodiments, the chirped pulses are configured to produce a 1-dimensional signal along an axis of the permanent gradient field. According to various embodiments, the 1-dimensional signal is a first 1-dimensional signal, the gradient pulses are configured to generate a second 1-dimensional signal and a third 1-dimensional signal orthogonal to each other and to the axis of the permanent gradient field.

According to various embodiments, the gradient pulses are configured for encoding spatial information into a signal. According to various embodiments, a combination of permanent gradient fields and chirped pulses is configured for slice selection in both permanent and frequency encoding gradients.

According to various embodiments, the target subject is an anatomical part of the body.

According to various embodiments, the receive coil comprises an array of receive coils, and each of the array of receive coils is configured for a particular anatomical part of the body. According to various embodiments, the chirped pulses induce a signal in the target body, and the signal is received by the receive coil.

According to various embodiments, the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with a blanking signal. According to various embodiments, a blanking signal is utilized to turn the system on and off to enable and disable, respectively, the radio frequency amplifier.

According to various embodiments, the imaging system additionally includes a tuning frame and a radio frequency transmit coil, wherein the tuning frame is configured to change a frequency response of the transmit coil. According to various embodiments, the transmit coil is non-planar and positioned to partially surround the region of interest.

According to various embodiments, the imaging system further comprises a single-sided gradient coil set, wherein the gradient coil set is non-planar and positioned to partially surround the region of interest, and wherein the gradient coil set is configured to project magnetic field gradients to the region of interest.

According to various embodiments, the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within a region of interest. According to various embodiments, the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the receive coil is smaller than the region of interest.

Figure 17 is a flow diagram of a method S300 for performing magnetic resonance imaging, in accordance with various embodiments. The method S300 includes providing a permanent gradient magnetic field at step S310.

As shown in fig. 17, the method S300 includes: in step S320, the receiving coil is placed close to the target subject. The method S300 includes: in step S330, a sequence of chirped pulses having a wide bandwidth is applied. The method S300 includes: in step S340, slice selection gradients with the same wide bandwidth are selected.

As shown in fig. 17, the method S300 includes: in step S350, a multi-slice excitation technique is applied along the axis of the permanent gradient field. The method S300 includes: in step S360, a plurality of gradient pulses orthogonal to the permanent gradient magnetic field are applied. The method S300 includes: in step S370, a signal of the target subject is acquired through the receiving coil. The method S300 includes: in step S380, a magnetic resonance image of the target subject is formed.

According to various embodiments, the application of chirped pulses, multi-slice excitation techniques, and gradient pulses are timed such that the magnetization refocuses each time a signal is acquired. According to various embodiments, each magnetization is focused in a region of interest, wherein the region of interest surrounds the target subject. According to various embodiments, the region of interest has a diameter of 4 to 12 inches.

According to various embodiments, the chirped pulses comprise the same bandwidth and different durations. According to various embodiments, the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

According to various embodiments, the chirped pulses are configured to produce a 1-dimensional signal along an axis of the permanent gradient field. According to various embodiments, the 1-dimensional signal is a first 1-dimensional signal, the gradient pulses are configured to generate a second 1-dimensional signal and a third 1-dimensional signal orthogonal to each other and to the axis of the permanent gradient field.

According to various embodiments, the gradient pulses are configured for encoding spatial information into a signal. According to various embodiments, a combination of permanent gradient fields and chirped pulses is configured for slice selection in both permanent and frequency encoding gradients.

According to various embodiments, the target subject is an anatomical part of the body.

According to various embodiments, the receive coil comprises an array of receive coils, and each of the array of receive coils is configured for a particular anatomical part of the body. According to various embodiments, the chirped pulses induce a signal in the target body, and the signal is received by the receive coil.

According to various embodiments, the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with a blanking signal. According to various embodiments, a blanking signal is utilized to turn the system on and off to enable and disable, respectively, the radio frequency amplifier.

According to various embodiments, the imaging system further comprises a tuning frame and a radio frequency transmit coil, wherein the tuning frame is configured to change a frequency response of the transmit coil. According to various embodiments, the transmit coil is non-planar and positioned to partially surround the region of interest.

According to various embodiments, the imaging system further comprises a single-sided gradient coil set, wherein the gradient coil set is non-planar and positioned to partially surround the region of interest, and wherein the gradient coil set is configured to project magnetic field gradients to the region of interest.

According to various embodiments, the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within a region of interest. According to various embodiments, the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the receive coil is smaller than the region of interest.

Computer implemented system

Fig. 18 is a block diagram that illustrates a computer system 1800, in accordance with various embodiments. According to various embodiments, the methods S100, S200 and S300 for performing magnetic resonance imaging can be implemented via computer software or hardware. According to various embodiments, control systems, such as control systems 1190, 1290, 1390, and 1490, or control and interface systems, such as systems 1294, 1394, and 1494, can be communicatively connected to computer system 1800 via a network connection, which may be a "hardwired" physical network connection (e.g., the internet, a LAN, a WAN, a VPN, etc.) or a wireless network connection (e.g., Wi-Fi, WLAN, etc.). In various embodiments, computer system 1800 can be a workstation, a mainframe computer, a distributed computing node (a part of a "cloud computing" or distributed network system), a personal computer, a mobile device, and so forth.

According to various embodiments, computer system 1800 can include a bus 1802 or other communication mechanism for communicating information, and a processor 1804 coupled with bus 1802 for processing information. In various embodiments, the computer system 1800 can also include a memory, which can be a Random Access Memory (RAM)1806 or other dynamic storage device, coupled to the bus 1802 for determining instructions to be executed by the processor 1804. Memory can also be used for storing temporary variables or other intermediate information during execution of instructions to be executed by processor 1804. In various embodiments, computer system 1800 can additionally include a Read Only Memory (ROM)1808 or other static storage device coupled to bus 1802 for storing static information and instructions for processor 1804. A storage device 1810, such as a magnetic disk or optical disk, can be provided and coupled to bus 1802 for storing information and instructions 1810.

In various embodiments, the computer system 1800 can be coupled via the bus 1802 to a display 1812, such as a Cathode Ray Tube (CRT) or Liquid Crystal Display (LCD), for displaying information to a computer user. An input device 1814, including alphanumeric and other keys, can be coupled to bus 1802 for communicating information and command selections to processor 1804. Another type of user input device is cursor control 1816, such as a mouse, a trackball, or cursor direction keys for communicating direction information and command selections to processor 1804 and for controlling cursor movement on display 1812. This input device 1814 typically has two degrees of freedom in two axes, a first axis (i.e., x) and a second axis (i.e., y), that allows the device to specify positions in a plane. However, it should be understood that input devices 1814 that allow 3-dimensional (x, y, and z) cursor movement are also contemplated herein.

According to some embodiments of the present teachings, the results can be provided by the computer system 1800 in response to the processor 1804 executing one or more sequences of one or more instructions contained in memory 1806. Such instructions can be read into memory 1806 from another computer-readable medium, such as storage device 1810, or a computer-readable storage medium. Execution of the sequences of instructions contained in memory 1806 enables processor 1804 to perform processes described herein. Alternatively, hardwired circuitry can be used in place of or in combination with software instructions to implement the present teachings. Thus, implementations of the present teachings are not limited to any specific combination of hardware circuitry and software.

The term "computer-readable medium" (e.g., data store, etc.) or "computer-readable storage medium" as used herein refers to any medium that participates in providing instructions to processor 1804 for execution. Such a medium may take many forms, including but not limited to, non-volatile media, and transmission media. Examples of non-volatile media can include, but are not limited to, optical solid-state disks, such as storage device 1810. Examples of volatile media can include, but are not limited to, dynamic memory such as the memory 1806 or the like. Examples of transmission media can include, but are not limited to, coaxial cables, copper wire and fiber optics, including the wires that comprise bus 1802.

Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, or any other magnetic medium, a CD-ROM, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, an EPROM, a flash EEPROM, any other memory chip or cartridge, or any other tangible medium from which a computer can read.

In addition to computer readable media, instructions or data can be provided as signals on transmission media included in a communication device or system to provide a processor 1804 of computer system 1800 with a sequence of one or more instructions for execution. For example, the communication device may include a transceiver having signals indicative of instructions and data. The instructions and data are configured to cause one or more processors to implement the functions outlined in the disclosure herein. Representative examples of data communication transmission connections can include, but are not limited to, telephone modem connections, Wide Area Networks (WANs), Local Area Networks (LANs), infrared data connections, NFC connections, and the like.

It should be understood that the methods, flow charts, diagrams, and accompanying disclosure described herein can be implemented using the computer system 1800 as a standalone device or on a distributed network of shared computer processing resources, such as a cloud computing network or the like.

Depending on the application, the methods described herein may be implemented by various means. For example, the methods may be implemented in hardware, firmware, software, or any combination thereof. For a hardware implementation, the processing units may be implemented within one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof.

In various embodiments, the methods of the present teachings may be implemented as firmware and/or as software programs and applications written in conventional programming languages, such as C, C + +, Python, and the like. If implemented as firmware and/or software, the embodiments described herein can be implemented on a non-transitory computer readable medium having a program stored therein for causing a computer to perform a method as described above. It should be understood that the various engines described herein can be provided on a computer system, such as computer system 1800, etc., whereby processor 1804 will perform the analysis and determinations provided by these engines and comply with instructions provided by any one or combination of memory component 1806/1808/1810 and user input provided via input device 1814.

According to various embodiments, a non-transitory computer-readable medium is provided, in which a program is stored for causing a computer to execute a method for performing magnetic resonance imaging. According to various embodiments, the method includes providing a magnetic resonance imaging system. According to various embodiments, the system comprises: a radio frequency receiving system including a radio frequency receiving coil, and a housing. According to various embodiments, the housing comprises: a permanent magnet for providing a non-uniform permanent gradient field, a radio frequency transmission system and a single-sided gradient coil set. According to various embodiments, the method additionally comprises: placing a receive coil proximate to a target subject; applying a sequence of chirped pulses via a transmission system; applying a multi-slice excitation along the non-uniform permanent gradient field; applying a plurality of gradient pulses via a gradient coil set orthogonal to the non-uniform permanent gradient field; acquiring a signal of a target subject via a receiving system, wherein the signal comprises at least two chirps; and forming a magnetic resonance image of the target subject.

According to various embodiments, the application of chirped pulses, multi-slice excitation, and gradient pulses are timed such that the magnetization refocuses each time the receiving system acquires a signal. According to various embodiments, the system further comprises a power supply, wherein the power supply is configured to flow a current through at least one of the radio frequency transmission system and the single-sided gradient coil set to generate an electromagnetic field in a region of interest, wherein the region of interest surrounds the target body. According to various embodiments, the region of interest has a diameter of 4 to 12 inches.

According to various embodiments, the multi-slice excitation includes exciting a plurality of slices along an axis of the non-uniform permanent gradient field, wherein each of the plurality of slices has a bandwidth of a wide bandwidth similar to a chirped pulse. According to various embodiments, the chirped pulses comprise the same bandwidth and different durations. According to various embodiments, the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

According to various embodiments, the chirped pulses are configured to produce a 1-dimensional signal along an axis of the non-uniform permanent gradient field. According to various embodiments, the 1-dimensional signal is a first 1-dimensional signal, the gradient pulses are configured to generate a second 1-dimensional signal and a third 1-dimensional signal that are orthogonal to each other and to an axis of the non-uniform permanent gradient field.

According to various embodiments, the gradient pulses are configured for encoding spatial information into a signal. According to various embodiments, a combination of non-uniform permanent gradient fields and chirped pulses is configured for slice selection in non-uniform permanent gradients and frequency encoding gradients. According to various embodiments, the target subject is an anatomical part of the body.

According to various embodiments, the receive coil comprises an array of receive coils, and each of the array of receive coils is configured for a particular anatomical part of the body. According to various embodiments, the chirped pulses induce a signal in the target body, and the signal is received by the receive coil. According to various embodiments, each of the at least two chirped pulses is split into two components that are 90 degrees out of phase. According to various embodiments, each of the at least two chirps is split into two components, which are sent to two separate ports of the transmission system.

According to various embodiments, the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with a blanking signal. According to various embodiments, a blanking signal is utilized to turn on and off a control system to enable and disable, respectively, a radio frequency amplifier.

According to various embodiments, a radio frequency transmission system includes a transmission coil that is non-planar and positioned to partially surround a region of interest. According to various embodiments, the magnetic resonance imaging system further comprises a tuning block, wherein the tuning block is configured to change the frequency response of the transmit coil. According to various embodiments, the gradient coil set is non-planar and positioned to partially surround the region of interest, and wherein the gradient coil set is configured to project magnetic field gradients to the region of interest.

According to various embodiments, the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within a region of interest. According to various embodiments, the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the receive coil is smaller than the region of interest. According to various embodiments, the transmit coil and the gradient coil set are concentric with respect to the region of interest.

According to various embodiments, a non-transitory computer-readable medium is provided, in which a program is stored for causing a computer to execute a method for performing magnetic resonance imaging. According to various embodiments, a method includes providing an imaging system including a radio frequency receive coil and a permanent magnet for providing a permanent gradient field. According to various embodiments, the method additionally comprises: placing a receive coil proximate to a target subject; applying a sequence of chirped pulses having a wide bandwidth; applying a multi-slice excitation along the permanent gradient field, wherein the multi-slice excitation comprises exciting a plurality of slices along an axis of the permanent gradient field, wherein each of the plurality of slices has a bandwidth of a wide bandwidth similar to that of a chirped pulse; applying phase encoding fields along two orthogonal directions perpendicular to the axis of the permanent gradient field; and acquiring a magnetic resonance image of the target subject.

According to various embodiments, the application of chirped pulses, multi-slice excitation, and gradient pulses are timed such that the magnetization refocuses each time a signal is acquired. According to various embodiments, each magnetization is focused in a region of interest, wherein the region of interest surrounds the target subject. According to various embodiments, the region of interest has a diameter of 4 to 12 inches.

According to various embodiments, the chirped pulses comprise the same bandwidth and different durations. According to various embodiments, the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

According to various embodiments, the chirped pulses are configured to produce a 1-dimensional signal along an axis of the permanent gradient field. According to various embodiments, the method further comprises applying a plurality of gradient pulses via a gradient coil set orthogonal to the non-uniform permanent gradient field, wherein the 1-dimensional signal is a first 1-dimensional signal, the gradient pulses being configured to generate a second 1-dimensional signal and a third 1-dimensional signal orthogonal to each other and to an axis of the permanent gradient field.

According to various embodiments, the method additionally comprises: applying a plurality of gradient pulses via a gradient coil set orthogonal to the non-uniform permanent gradient field, wherein the gradient pulses are configured for encoding spatial information into a signal. According to various embodiments, a combination of permanent gradient fields and chirped pulses is configured for slice selection in both permanent and frequency encoding gradients. According to various embodiments, the target subject is an anatomical part of the body.

According to various embodiments, the receive coil comprises an array of receive coils, and each of the array of receive coils is configured for a particular anatomical part of the body. According to various embodiments, the chirped pulses induce a signal in the target body, and the signal is received by the receive coil.

According to various embodiments, the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with a blanking signal. According to various embodiments, a blanking signal is utilized to turn the system on and off to enable and disable, respectively, the radio frequency amplifier.

According to various embodiments, the imaging system additionally includes a tuning frame and a radio frequency transmit coil, wherein the tuning frame is configured to change a frequency response of the transmit coil. According to various embodiments, the transmit coil is non-planar and positioned to partially surround the region of interest.

According to various embodiments, the imaging system further comprises a single-sided gradient coil set, wherein the gradient coil set is non-planar and positioned to partially surround the region of interest, and wherein the gradient coil set is configured to project magnetic field gradients to the region of interest.

According to various embodiments, the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within a region of interest. According to various embodiments, the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the receive coil is smaller than the region of interest.

According to various embodiments, a non-transitory computer-readable medium is provided, in which a program is stored for causing a computer to execute a method for performing magnetic resonance imaging. According to various embodiments, the method comprises: providing a permanent gradient magnetic field; placing a receive coil proximate to a target subject; applying a sequence of chirped pulses having a wide bandwidth; selecting slice selection gradients having the same wide bandwidth; applying a multi-slice excitation technique along an axis of the permanent gradient magnetic field; applying a plurality of gradient pulses orthogonal to the permanent gradient magnetic field; acquiring signals of a target subject via a receiving coil; and forming a magnetic resonance image of the target subject.

According to various embodiments, the application of chirped pulses, multi-slice excitation techniques, and gradient pulses are timed such that the magnetization refocuses each time a signal is acquired. According to various embodiments, each magnetization is focused in a region of interest, wherein the region of interest surrounds the target subject. According to various embodiments, the region of interest has a diameter of 4 to 12 inches.

According to various embodiments, the chirped pulses comprise the same bandwidth and different durations. According to various embodiments, the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

According to various embodiments, the chirped pulses are configured to produce a 1-dimensional signal along an axis of the permanent gradient field. According to various embodiments, the 1-dimensional signal is a first 1-dimensional signal, the gradient pulses are configured to generate a second 1-dimensional signal and a third 1-dimensional signal orthogonal to each other and to the axis of the permanent gradient field.

According to various embodiments, the gradient pulses are configured for encoding spatial information into a signal. According to various embodiments, a combination of permanent gradient fields and chirped pulses is configured for slice selection in both permanent and frequency encoding gradients. According to various embodiments, the target subject is an anatomical part of the body.

According to various embodiments, the receive coil comprises an array of receive coils, and each of the array of receive coils is configured for a particular anatomical part of the body. According to various embodiments, the chirped pulses induce a signal in the target body, and the signal is received by the receive coil.

According to various embodiments, the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with a blanking signal. According to various embodiments, a blanking signal is utilized to turn the system on and off to enable and disable, respectively, the radio frequency amplifier.

According to various embodiments, the imaging system additionally includes a tuning frame and a radio frequency transmit coil, wherein the tuning frame is configured to change a frequency response of the transmit coil. According to various embodiments, the transmit coil is non-planar and positioned to partially surround the region of interest.

According to various embodiments, the imaging system further comprises a single-sided gradient coil set, wherein the gradient coil set is non-planar and positioned to partially surround the region of interest, and wherein the gradient coil set is configured to project magnetic field gradients to the region of interest.

According to various embodiments, the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within a region of interest. According to various embodiments, the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the receive coil is smaller than the region of interest.

Detailed description of the embodiments

Example 1. A method for performing magnetic resonance imaging comprising providing a magnetic resonance imaging system comprising: a radio frequency receive system including a radio frequency receive coil, and a housing, wherein the housing includes a permanent magnet for providing a non-uniform permanent gradient field, a radio frequency transmit system, and a single-sided gradient coil set. The method further comprises the following steps: placing a receive coil proximate to a target subject; applying a sequence of chirped pulses via a transmission system; applying a multi-slice excitation along the non-uniform permanent gradient field; applying a plurality of gradient pulses via a gradient coil set orthogonal to the non-uniform permanent gradient field; acquiring a signal of a target subject via a receiving system, wherein the signal comprises at least two chirps; and forming a magnetic resonance image of the target subject.

Example 2. The method of embodiment 1 wherein the application of the chirped pulses, the multi-slice excitation, and the gradient pulses are timed such that the magnetization refocuses each time the signal is acquired by the receiving system.

Example 3. The method according to any of the preceding embodiments, further comprising a power supply, wherein the power supply is configured to flow a current through at least one of the radio frequency transmission system and the set of single-sided gradient coils to generate an electromagnetic field in a region of interest, wherein the region of interest surrounds the target body.

Example 4. The method of embodiment 3, wherein the region of interest has a diameter of 4 to 12 inches.

Example 5. The method of any preceding embodiment, wherein the multi-slice excitation comprises exciting a plurality of slices along an axis of the non-uniform permanent gradient field, wherein each of the plurality of slices has a bandwidth similar to a wide bandwidth of a chirped pulse.

Example 6. The method of any of the preceding embodiments, wherein the chirped pulses comprise the same bandwidth and different durations.

Example 7. The method of any preceding embodiment, wherein the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

Example 8. The method according to any of the preceding embodiments, wherein the chirped pulses are configured to produce a 1-dimensional signal along an axis of the non-uniform permanent gradient field.

Example 9. The method of embodiment 8, wherein the 1-dimensional signal is a first 1-dimensional signal and the gradient pulses are configured to produce a second 1-dimensional signal and a third 1-dimensional signal that are orthogonal to each other and to the axis of the non-uniform permanent gradient field.

Example 10. The method according to any preceding embodiment, wherein the gradient pulses are configured for encoding spatial information into the signal.

Example 11. The method according to any preceding embodiment, wherein the combination of non-uniform permanent gradient fields and chirped pulses is configured for slice selection in non-uniform permanent gradients and frequency encoding gradients.

Example 12. The method according to any of the preceding embodiments, wherein the target subject is an anatomical part of a body.

Example 13. The method according to any of the preceding embodiments, wherein the receive coil comprises an array of receive coils, and each receive coil of the array of receive coils is configured for a particular anatomical part of the body.

Example 14. The method according to any of the preceding embodiments, wherein the chirped pulses induce a signal in the target body, and the signal is received by the receive coil.

Example 15. The method according to any of the preceding embodiments, wherein each of the at least two chirped pulses is split into two components that are 90 degrees out of phase.

Example 16. The method of any of the preceding embodiments, wherein each of the at least two chirps is split into two components, the two components being sent to two separate ports of the transmission system.

Example 17. The method according to any of the preceding embodiments, wherein the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with the blanking signal.

Example 18. The method of embodiment 17 wherein the blanking signal is utilized to turn on and off the control system to enable and disable, respectively, the radio frequency amplifier.

Example 19. The method of embodiment 3 wherein the radio frequency transmission system comprises a transmission coil that is non-planar and positioned to partially surround the region of interest.

Example 20. The method of embodiment 19, the magnetic resonance imaging system further comprising a tuning block, wherein the tuning block is configured to change the frequency response of the transmit coil.

Example 21. The method of embodiment 3 wherein the gradient coil set is non-planar and positioned to partially surround the region of interest, and wherein the gradient coil set is configured to project magnetic field gradients to the region of interest.

Example 22. The method of embodiment 3 wherein the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within the region of interest.

Example 23. The method of embodiment 3, wherein the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the receive coil is smaller than the region of interest.

Example 24. The method of embodiment 19 wherein the transmit coil and the gradient coil set are concentric about the region of interest.

Example 25. A method for performing magnetic resonance imaging, comprising providing an imaging system comprising: a radio frequency receive coil and a permanent magnet for providing a permanent gradient field. The method further comprises the following steps: placing a receive coil proximate to a target subject; applying a sequence of chirped pulses having a wide bandwidth; applying a multi-slice excitation along the permanent gradient field, wherein the multi-slice excitation comprises exciting a plurality of slices along an axis of the permanent gradient field, wherein each of the plurality of slices has a bandwidth of a wide bandwidth similar to that of a chirped pulse; applying phase encoding fields along two orthogonal directions perpendicular to the axis of the permanent gradient field; and acquiring a magnetic resonance image of the target subject.

Example 26. The method of embodiment 25 wherein the chirped pulses, multi-slice excitation, and application of gradient pulses are timed such that the magnetization refocuses each time a signal is acquired.

Example 27. The method of embodiment 26, wherein each magnetization is focused in a region of interest, wherein the region of interest surrounds the target subject.

Example 28. The method of embodiment 27, wherein the region of interest has a diameter of 4 to 12 inches.

Example 29. The method of any one of embodiments 25 through 28 wherein the chirped pulses comprise the same bandwidth and different durations.

Example 30. The method of embodiment 29, wherein the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

Example 31. The method of any of embodiments 25-30 wherein the chirped pulses are configured to produce a 1-dimensional signal along an axis of the permanent gradient field.

Example 32. The method of embodiment 31, further comprising applying a plurality of gradient pulses via a gradient coil set orthogonal to the non-uniform permanent gradient field, wherein the 1-dimensional signal is a first 1-dimensional signal, the gradient pulses configured to produce a second 1-dimensional signal and a third 1-dimensional signal that are orthogonal to each other and to an axis of the permanent gradient field.

Example 33. The method of any of embodiments 25 to 32, further comprising applying a plurality of gradient pulses via a gradient coil set orthogonal to the non-uniform permanent gradient field, wherein the gradient pulses are configured to encode spatial information into the signals.

Example 34. The method according to any of embodiments 25 to 33, wherein the combination of permanent gradient fields and chirped pulses is configured for slice selection in permanent gradients and frequency encoding gradients.

Example 35. The method of any of embodiments 25-34, wherein the target subject is an anatomical part of a body.

Example 36. The method according to any of embodiments 25-35, wherein the receive coil comprises an array of receive coils, and each receive coil in the array of receive coils is configured for a particular anatomical part of the body.

Example 37. The method of any one of embodiments 25 through 36 wherein the chirped pulses induce a signal in the target body and the signal is received by a receive coil.

Example 38. The method according to any of embodiments 25 to 37, wherein the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with a blanking signal.

Example 39. The method of embodiment 38 wherein the blanking signal is utilized to turn the system on and off to enable and disable, respectively, the radio frequency amplifier.

Example 40. The method of embodiment 27, the imaging system further comprising a tuning frame and a radio frequency transmit coil, wherein the tuning frame is configured to change a frequency response of the transmit coil.

Example 41. The method of embodiment 40 wherein the transmit coil is non-planar and is positioned to partially surround the region of interest.

Example 42. The method of embodiment 27 wherein the imaging system further comprises a single-sided gradient coil set, wherein the gradient coil set is non-planar and positioned to partially surround the region of interest, and wherein the gradient coil set is configured to project magnetic field gradients to the region of interest.

Example 43. The method of embodiment 27 wherein the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within a region of interest.

Example 44. The method of embodiment 27, wherein the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the receive coil is smaller than the region of interest.

Example 45. A method for performing magnetic resonance imaging comprising: providing a permanent gradient magnetic field; placing a receive coil proximate to a target subject; applying a sequence of chirped pulses having a wide bandwidth; selecting slice selection gradients having the same wide bandwidth; applying a multi-slice excitation technique along an axis of the permanent gradient magnetic field; applying a plurality of gradient pulses orthogonal to the permanent gradient magnetic field; acquiring signals of a target subject via a receiving coil; and forming a magnetic resonance image of the target subject.

Example 46. The method of embodiment 45 wherein the chirped pulses, the multi-slice excitation technique, and the application of gradient pulses are timed such that the magnetization refocuses each time a signal is acquired.

Example 47. The method of embodiment 46, wherein each magnetization is focused in a region of interest, wherein the region of interest surrounds the target subject.

Example 48. The method of embodiment 47, wherein the region of interest has a diameter of 4 to 12 inches.

Example 49. The method of any one of embodiments 45 through 48 wherein the chirped pulses comprise the same bandwidth and different durations.

Example 50. The method of embodiment 49, wherein the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

Example 51. The method of any of embodiments 45 through 50, wherein the chirped pulses are configured to produce a 1-dimensional signal along an axis of the permanent gradient field.

Example 52. The method of embodiment 51 wherein the 1-dimensional signal is a first 1-dimensional signal and the gradient pulses are configured to produce a second 1-dimensional signal and a third 1-dimensional signal that are orthogonal to each other and to the axis of the permanent gradient field.

Example 53. The method according to any of embodiments 45 to 52, wherein the gradient pulses are configured for encoding spatial information into the signal.

Example 54. The method according to any of embodiments 45 to 53, wherein a combination of permanent gradient fields and chirped pulses is configured for slice selection in permanent and frequency encoding gradients.

Example 55. The method of any of embodiments 45-54, wherein the target subject is an anatomical part of a body.

Example 56. The method according to any of embodiments 45-55, wherein the receive coil comprises an array of receive coils, and each receive coil in the array of receive coils is configured for a particular anatomical part of the body.

Example 57. The method of any of embodiments 45 to 56, wherein the chirped pulses induce a signal in the target body and the signal is received by a receive coil.

Example 58. The method according to any of embodiments 45 to 57, wherein the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with a blanking signal.

Example 59. The method of embodiment 58 wherein the blanking signal is utilized to turn the system on and off to enable and disable, respectively, the radio frequency amplifier.

Example 60. The method of embodiment 47, the imaging system further comprising a tuning block and a radio frequency transmit coil, wherein the tuning block is configured to change a frequency response of the transmit coil.

Example 61. The method of embodiment 60 wherein the transmit coil is non-planar and is positioned to partially surround the region of interest.

Example 62. The method of embodiment 47 wherein the imaging system further comprises a single-sided gradient coil set, wherein the gradient coil set is non-planar and positioned to partially surround the region of interest, and wherein the gradient coil set is configured to project magnetic field gradients to the region of interest.

Example 63. The method of embodiment 47 wherein the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within a region of interest.

Example 64. The method of embodiment 47, wherein the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the receive coil is smaller than the region of interest.

Example 65. A magnetic resonance imaging system includes a radio frequency receive system comprising: a radio frequency receive coil configured to be placed in proximity to a target subject, wherein the receive system is configured to deliver a signal of the target subject for forming a magnetic resonance image of the target subject, wherein the signal comprises at least two chirped pulses, and a housing, wherein the housing comprises a permanent magnet for providing a non-uniform permanent gradient field, wherein the imaging system is configured to apply a multi-slice excitation along the non-uniform permanent gradient field, the radio frequency transmit system is configured to deliver a sequence of chirped pulses, and the set of single-sided gradient coils is configured to deliver a plurality of gradient pulses orthogonal to the non-uniform permanent gradient field.

Example 66. The system of embodiment 65, further comprising a power supply, wherein the power supply is configured to flow a current through at least one of the radio frequency transmission system and the set of single-sided gradient coils to generate an electromagnetic field in a region of interest, wherein the region of interest surrounds the target body.

Example 67. The system of embodiment 66, wherein the region of interest has a diameter of 4 to 12 inches.

Example 68. The method of any of embodiments 65 to 67 wherein the imaging system is configured to apply multi-slice excitation comprising exciting a plurality of slices along an axis of the non-uniform permanent gradient field, wherein each of the plurality of slices has a bandwidth of a wide bandwidth similar to that of the chirped pulse.

Example 69. The system of any of embodiments 65 through 68 wherein the chirped pulses comprise the same bandwidth and different durations.

Example 70. The system of any of embodiments 65 to 69 wherein the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

Example 71. The system of any of embodiments 65 to 70, wherein the chirped pulse is configured to produce a 1-dimensional signal along an axis of the non-uniform permanent gradient field.

Example 72. The system of embodiment 71, wherein the 1-dimensional signal is a first 1-dimensional signal and the gradient pulses are configured to produce a second 1-dimensional signal and a third 1-dimensional signal that are orthogonal to each other and to an axis of the non-uniform permanent gradient field.

Example 73. The system according to any of embodiments 65 to 72, wherein the gradient pulses are configured for encoding spatial information into the signal.

Example 74. The system according to any of embodiments 65 to 73, wherein the combination of non-uniform permanent gradient fields and chirped pulses is configured for slice selection in non-uniform permanent gradients and frequency encoding gradients.

Example 75. The system of any of embodiments 65-74, wherein the target subject is an anatomical part of a body.

Example 76. The system according to any of embodiments 65-75, wherein the receive coil comprises an array of receive coils, and each receive coil in the array of receive coils is configured for a particular anatomical part of the body.

Example 77. The system of any of embodiments 65 to 76 wherein the chirped pulses induce a signal in the target body and the receive coil is configured to receive the signal.

Example 78. The system of any of embodiments 65 to 77 wherein each of the at least two chirped pulses is split into two components that are 90 degrees out of phase.

Example 79. The system of any of embodiments 65 to 78, wherein the transmission system further comprises two separate ports configured to generate at least two chirped pulses.

Example 80. The system according to any of embodiments 65-79, wherein the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with a blanking signal.

Example 81. The system of embodiment 80, further comprising a radio frequency amplifier that is enabled and disabled when the control system is turned on and off using the blanking signal.

Example 82. The system of embodiment 66 wherein the radio frequency transmission system comprises a transmission coil that is non-planar and positioned to partially surround the region of interest.

Example 83. The system of embodiment 82, wherein the magnetic resonance imaging system further comprises a tuning block, wherein the tuning block is configured to change the frequency response of the transmit coil.

Example 84. The system of embodiment 66 wherein the gradient coil set is non-planar and positioned to partially surround the region of interest and wherein the gradient coil set is configured to project magnetic field gradients to the region of interest.

Example 85. The system of embodiment 66, wherein the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within the region of interest.

Example 86. The system of embodiment 66 wherein the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration wherein the receive coil is smaller than the region of interest.

Example 87. The system of embodiment 82 wherein the transmit coil and the gradient coil set are concentric about the region of interest.

Example 88. A non-transitory computer readable medium having stored therein instructions for causing a computer to execute a method for performing magnetic resonance imaging, the method comprising providing a magnetic resonance imaging system comprising: a radio frequency receiving system comprising a radio frequency receiving coil, and a housing, wherein the housing comprises a permanent magnet for providing a non-uniform permanent gradient field, a radio frequency transmitting system, and a single-sided gradient coil set. The method further comprises the following steps: placing a receive coil proximate to a target subject; applying a sequence of chirped pulses via a transmission system; applying a multi-slice excitation along the non-uniform permanent gradient field; applying a plurality of gradient pulses via a gradient coil set orthogonal to the non-uniform permanent gradient field; acquiring a signal of a target subject via a receiving system, wherein the signal comprises at least two chirps; and forming a magnetic resonance image of the target subject.

Example 89. The method of embodiment 88 wherein the chirped pulses, multi-slice excitation, and application of gradient pulses are timed such that magnetization refocuses each time a signal is acquired by the receiving system.

Example 90. The method according to any one of embodiments 88 and 89, further comprising a power supply, wherein the power supply is configured to flow a current through at least one of the radio frequency transmission system and the set of single-sided gradient coils to generate an electromagnetic field in a region of interest, wherein the region of interest surrounds the target body.

Example 91. The method of embodiment 90, wherein the region of interest has a diameter of 4 to 12 inches.

Example 92. The method of any of embodiments 88 to 91, wherein multi-slice excitation comprises exciting a plurality of slices along an axis of the non-uniform permanent gradient field, wherein each of the plurality of slices has a bandwidth of a wide bandwidth similar to a chirped pulse.

Example 93. The method of any one of embodiments 88 through 92 wherein the chirped pulses comprise the same bandwidth and different durations.

Example 94. The method of any one of embodiments 88 to 93, wherein the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

Example 95. The method of any of embodiments 88 to 94 wherein the chirped pulses are configured to produce a 1-dimensional signal along an axis of the non-uniform permanent gradient field.

Example 96. The method of embodiment 95 wherein the 1-dimensional signal is a first 1-dimensional signal and the gradient pulses are configured to produce a second 1-dimensional signal and a third 1-dimensional signal that are orthogonal to each other and to the axis of the non-uniform permanent gradient field.

Example 97. The method of any of embodiments 88 to 96 wherein the gradient pulses are configured for encoding spatial information into the signal.

Example 98. The method of any of embodiments 88 to 97 wherein the combination of non-uniform permanent gradient fields and chirped pulses is configured for slice selection in non-uniform permanent gradients and frequency encoding gradients.

Example 99. The method of any of embodiments 88 to 98, wherein the target subject is an anatomical part of a body.

Example 100. The method of any of embodiments 88 to 98 wherein the receive coil comprises an array of receive coils and each receive coil of the array of receive coils is configured for a particular anatomical part of the body.

Example 101. The method of any of embodiments 88 to 100 wherein the chirped pulses induce a signal in the target body and the signal is received by a receive coil.

Example 102. The method of any of embodiments 88 to 101 wherein each of the at least two chirped pulses is split into two components that are 90 degrees out of phase.

Example 103. The method of any of embodiments 88 to 102 wherein each of the at least two chirps is split into two components, the two components being sent to two separate ports of the transmission system.

Example 104. The method of any of embodiments 88 to 103 wherein the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with a blanking signal.

Example 105. The method of embodiment 104 wherein the blanking signal is utilized to turn on and off the control system to enable and disable, respectively, the radio frequency amplifier.

Example 106. The method of embodiment 90 wherein the radio frequency transmission system comprises a transmission coil that is non-planar and is positioned to partially surround the region of interest.

Example 107. In accordance with the method of embodiment 106, the magnetic resonance imaging system further comprises a tuning block, wherein the tuning block is configured to change the frequency response of the transmit coil.

Example 108. The method of embodiment 90 wherein the gradient coil set is non-planar and positioned to partially surround the region of interest, and wherein the gradient coil set is configured to project magnetic field gradients to the region of interest.

Example 109. The method of embodiment 90 wherein the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within a region of interest.

Example 110. The method of embodiment 90, wherein the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the receive coil is smaller than the region of interest.

Example 111. The method of embodiment 106 wherein the transmit coil and the gradient coil set are concentric about the region of interest.

Example 112. A non-transitory computer readable medium having stored therein instructions for causing a computer to execute a method for performing magnetic resonance imaging, the method comprising providing an imaging system comprising a radio frequency receive coil, and a permanent magnet for providing a permanent gradient field. The method further comprises the following steps: placing a receive coil proximate to a target subject; applying a sequence of chirped pulses having a wide bandwidth; applying a multi-slice excitation along the permanent gradient field, wherein the multi-slice excitation comprises exciting a plurality of slices along an axis of the permanent gradient field, wherein each of the plurality of slices has a bandwidth of a wide bandwidth similar to that of a chirped pulse; applying phase encoding fields along two orthogonal directions perpendicular to the axis of the permanent gradient field; and acquiring a magnetic resonance image of the target subject.

Example 113. The method of embodiment 112 wherein the chirped pulses, the multi-slice excitation, and the application of the gradient pulses are timed such that the magnetization refocuses each time a signal is acquired.

Example 114. The method of embodiment 113, wherein each magnetization is focused in a region of interest, wherein the region of interest surrounds the target subject.

Example 115. The method of embodiment 114, wherein the region of interest has a diameter of 4 to 12 inches.

Example 116. The method of any of embodiments 112-115, wherein the chirped pulses comprise the same bandwidth and different durations.

Example 117. The method of embodiment 116, wherein the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

Example 118. The method of any of embodiments 112 to 117 wherein the chirped pulses are configured to produce a 1-dimensional signal along an axis of the permanent gradient field.

Example 119. The method of embodiment 118, further comprising applying a plurality of gradient pulses via a gradient coil set orthogonal to the non-uniform permanent gradient field, wherein the 1-dimensional signal is a first 1-dimensional signal, the gradient pulses configured to produce a second 1-dimensional signal and a third 1-dimensional signal that are orthogonal to each other and to an axis of the permanent gradient field.

Example 120. The method of any of embodiments 112 to 119, further comprising applying a plurality of gradient pulses via a gradient coil set orthogonal to the non-uniform permanent gradient field, wherein the gradient pulses are configured for encoding spatial information into the signal.

Example 121. The method of any of embodiments 112 to 120 wherein the combination of permanent gradient fields and chirped pulses is configured for slice selection in permanent gradients and frequency encoding gradients.

Example 122. The method of any of embodiments 112-121, wherein the target subject is an anatomical part of a body.

Example 123. The method of any of embodiments 112-122, wherein the receive coil comprises an array of receive coils, and each receive coil of the array of receive coils is configured for a particular anatomical part of the body.

Example 124. The method of any of embodiments 112-123 wherein the chirped pulses induce a signal in the target body and the signal is received by a receive coil.

Example 125. The method according to any of embodiments 112 to 124, wherein the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with a blanking signal.

Example 126. The method of embodiment 125 wherein the blanking signal is utilized to turn the system on and off to enable and disable, respectively, the radio frequency amplifier.

Example 127. In accordance with the method of embodiment 114, the imaging system further comprises a tuning block and a radio frequency transmit coil, wherein the tuning block is configured to change a frequency response of the transmit coil.

Example 128. The method of embodiment 127, wherein the transmit coil is non-planar and is positioned to partially surround the region of interest.

Example 129. The method of embodiment 114 wherein the imaging system further comprises a single-sided gradient coil set, wherein the gradient coil set is non-planar and positioned to partially surround the region of interest, and wherein the gradient coil set is configured to project magnetic field gradients to the region of interest.

Example 130. The method of embodiment 114, wherein the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within the region of interest.

Example 131. The method of embodiment 114, wherein the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the receive coil is smaller than the region of interest.

Example 132. A non-transitory computer-readable medium in which a program for causing a computer to execute a method for performing magnetic resonance imaging is stored, the method comprising: providing a permanent gradient magnetic field; placing a receive coil proximate to a target subject; applying a sequence of chirped pulses having a wide bandwidth; selecting slice selection gradients having the same wide bandwidth; applying a multi-slice excitation technique along an axis of the permanent gradient magnetic field; applying a plurality of gradient pulses orthogonal to the permanent gradient magnetic field; acquiring signals of a target subject via a receiving coil; and forming a magnetic resonance image of the target subject.

Example 133. The method of embodiment 132 wherein the chirped pulses, the multi-slice excitation technique, and the application of gradient pulses are timed such that the magnetization refocuses each time a signal is acquired.

Example 134. The method of embodiment 133 wherein each magnetization is focused in a region of interest, wherein the region of interest surrounds the target subject.

Example 135. The method of embodiment 134, wherein the region of interest has a diameter of 4 to 12 inches.

Example 136. The method of any one of embodiments 132 through 135, wherein the chirped pulses comprise the same bandwidth and different durations.

Example 137. The method of embodiment 136, wherein the chirped pulses have a bandwidth ranging from 1kHz to 10kHz, 10kHz to 40kHz, 40kHz to 100kHz, 100kHz to 400kHz, 400kHz to 1MHz, or any range of bandwidths thereof.

Example 138. The method of any of embodiments 132-137, wherein the chirped pulses are configured to produce a 1-dimensional signal along an axis of the permanent gradient field.

Example 139. The method of embodiment 138, wherein the 1-dimensional signal is a first 1-dimensional signal, the gradient pulses configured to produce a second 1-dimensional signal and a third 1-dimensional signal that are orthogonal to each other and to an axis of the permanent gradient field.

Example 140. The method of any of embodiments 132 through 139, wherein the gradient pulses are configured for encoding spatial information into the signal.

Example 141. The method of any of embodiments 132 to 140, wherein a combination of permanent gradient fields and chirped pulses is configured for slice selection in permanent gradients and frequency encoding gradients.

Example 142. The method according to any one of embodiments 132-141, wherein the target subject is an anatomical part of a body.

Example 143. The method according to any of embodiments 132-142, wherein the receive coil comprises an array of receive coils, and each receive coil in the array of receive coils is configured for a particular anatomical part of the body.

Example 144. The method of any one of embodiments 132 through 143 wherein the chirped pulses induce a signal in the target body and the signal is received by a receive coil.

Example 145. The method of any of embodiments 132 through 144, wherein the magnetic resonance imaging system further comprises a signal conditioning block and a control system, wherein the signal conditioning block is configured to turn the control system on and off with a blanking signal.

Example 146. The method of embodiment 145 wherein turning on and off the system with the blanking signal enables and disables the radio frequency amplifier, respectively.

Example 147. The method of embodiment 134, the imaging system further comprising a tuning block and a radio frequency transmit coil, wherein the tuning block is configured to change a frequency response of the transmit coil.

Example 148. The method of embodiment 147 wherein the transmit coil is non-planar and is positioned to partially surround the region of interest.

Example 149. The method of embodiment 134 wherein the imaging system further comprises a single-sided gradient coil set, wherein the gradient coil set is non-planar and positioned to partially surround the region of interest, and wherein the gradient coil set is configured to project magnetic field gradients to the region of interest.

Example 150. The method of embodiment 134, wherein the receive coil is a flexible coil configured to be attached to an anatomical portion of a patient for imaging within the region of interest.

Example 151. The method of embodiment 134, wherein the receive coil exhibits one of a single loop coil configuration, a figure-8 coil configuration, or a butterfly coil configuration, wherein the receive coil is smaller than the region of interest.

While this specification contains many specifics of particular embodiments, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in combination in a single embodiment or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In some cases, multitasking and parallel processing may be advantageous. Moreover, the separation of various system modules and components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

References to "or" may be interpreted as being inclusive such that any term described using "or" may indicate any single, more than one, or all of the described terms. The terms "first," "second," "third," and the like do not necessarily denote an order, and are generally only used to distinguish between the same or similar items or elements.

Various modifications to the embodiments described in this disclosure may be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the claims are not intended to be limited to the embodiments shown herein but are to be accorded the widest scope consistent with the present disclosure, principles and novel features disclosed herein.