阅读说明：本技术 用于将患者定位在磁共振成像中的方法和设备 (Method and apparatus for positioning a patient in magnetic resonance imaging ) 是由 陈刚 A·M·纳尔逊 C·T·麦克纳尔蒂 J·C·乔丹 迈克尔·斯蒂芬·普尔 于 2019-07-19 设计创作，主要内容包括：根据一些方面,提供了能够对患者成像的磁共振成像系统。磁共振成像系统包括：至少一个B-0磁体,其用于产生对磁共振成像系统的B-0磁场有贡献的磁场；和构件,其被构造成与射频线圈设备的可释放固定机构接合,构件在使得当构件与射频线圈设备的可释放固定机构接合时,射频线圈设备基本上在磁共振成像系统的成像区域内被固定到磁共振成像系统的位置处附接到磁共振成像系统。(According to some aspects, a magnetic resonance imaging system capable of imaging a patient is provided. The magnetic resonance imaging system comprises: at least one B 0 Magnet for generating B for magnetic resonance imaging system 0 The magnetic field to which the magnetic field contributes; and a member configured to engage with the releasable securing mechanism of the radio frequency coil apparatus, the member being attached to the magnetic resonance imaging system at a location such that when the member is engaged with the releasable securing mechanism of the radio frequency coil apparatus, the radio frequency coil apparatus is secured to the magnetic resonance imaging system substantially within an imaging region of the magnetic resonance imaging system.)

1. A patient handling apparatus configured to facilitate positioning of a patient within a magnetic resonance imaging device, the patient handling apparatus comprising:

a patient support having a surface adapted to be positioned between the patient and a bed such that when the surface of the patient support is positioned, the surface of the patient support is below at least a portion of the patient's body; and

a fixed portion, comprising:

at least one first releasable securing mechanism configured to engage with a radio frequency component to secure the radio frequency component to the securing portion; and

at least one second releasable securing mechanism configured to engage with the magnetic resonance imaging device to secure the securing portion to the magnetic resonance imaging device.

2. The patient handling apparatus of claim 1, further comprising a bridge configured to bridge at least some space between the couch and the magnetic resonance imaging device.

3. The patient handling apparatus of claim 2, wherein the bridge provides support to at least a portion of the patient support when the patient is positioned within the magnetic resonance imaging device.

4. The patient handling device of claim 2, wherein the bridge is mountable to the bed.

5. The patient handling apparatus of claim 2, wherein the bridge is mountable to the magnetic resonance imaging device.

6. The patient handling apparatus of claim 2, wherein the bridge comprises a plastic surface to bridge at least some space between the bed and the magnetic resonance imaging device.

7. The patient handling apparatus of claim 1, wherein the patient support is configured to be collapsible.

8. The patient handling device of claim 7, wherein the patient support is configured to be foldable along a living hinge.

9. The patient handling device of claim 7, wherein the patient support is configured to be foldable along a piano hinge.

10. The patient handling device of claim 1, wherein the at least one first releasable securing mechanism comprises:

a slot; and

a retaining mechanism configured to inhibit movement of a portion of the radio frequency component when inserted into the slot.

11. The patient handling device of claim 10, wherein the slot comprises a keyhole slot, the keyhole slot comprising:

a first portion sized to allow a portion of the radio frequency component to be inserted into the keyhole slot in a first direction along a first axis and to allow a portion of the radio frequency component to be removed from the keyhole slot in a second direction opposite the first direction along the first axis; and

a second portion sized to prevent movement of a portion of the radio frequency component in at least a second direction along the first axis.

12. The patient handling device of claim 11, wherein the keyhole slot is configured to allow a portion of the radio frequency component to move from the first portion of the keyhole slot to the second portion of the keyhole slot in a first direction along a second axis.

13. The patient handling device of claim 12, wherein the retaining mechanism is configured to inhibit movement of the portion of the radio frequency component in at least a second direction along the second axis when the portion of the radio frequency component is moved into the second portion of the keyhole slot.

14. The patient handling device of claim 13, wherein the retention mechanism comprises a spring catch that allows a portion of the radio frequency component to move in a first direction along the second axis from a first portion of the keyhole slot into a second portion of the keyhole slot, and prevents movement of the portion of the radio frequency component in a second direction along the second axis when the portion of the radio frequency component has moved into the second portion of the keyhole slot.

15. The patient handling device of claim 14, wherein the spring catch comprises a plastic spring.

16. The patient handling device of claim 14, wherein the height of the spring catch is less than or equal to about 0.5 inches.

17. The patient handling device of claim 1, wherein the height of the spring catch is less than or equal to about 0.25 inches.

18. The patient handling device of claim 1, wherein the at least one second releasable securing mechanism comprises:

a retention mechanism having an introduction portion and a retention portion, the introduction portion allowing the second releasable securing mechanism to engage with a component of the magnetic resonance imaging apparatus in a first direction along a first axis, the retention portion preventing movement of the patient support relative to the magnetic resonance imaging apparatus at least in a second direction along the first axis when the at least one second releasable securing mechanism is engaged with a component of the magnetic resonance imaging system.

19. The patient handling apparatus of claim 18, wherein the member is attached to the magnetic resonance imaging device at a location such that the radio frequency coil apparatus is positioned within an imaging region of the magnetic resonance imaging device when the at least one securing mechanism is engaged with the member.

20. The patient handling device of claim 19, wherein the at least one second releasable securing mechanism comprises a release mechanism that, when actuated, moves the retaining portion to allow the at least one second releasable securing mechanism to disengage from the member of the magnetic resonance imaging system.

21. The patient handling device of claim 20, wherein the release mechanism comprises at least one spring.

22. The patient handling device of claim 21, wherein the release mechanism includes at least one pull to allow a user to pull the release mechanism to compress the at least one spring and move the holding portion.

23. The patient handling device of claim 21, wherein the at least one spring comprises at least one plastic spring.

24. The patient handling device of claim 21, wherein the height of the at least one spring is less than or equal to about 0.5 inches.

25. The patient handling device of claim 21, wherein the height of the at least one spring is less than or equal to about 0.25 inches.

26. The patient handling device of claim 1, wherein the patient support comprises molded plastic.

27. The patient handling device of claim 26, wherein the patient support comprises polyethylene.

28. The patient handling device of claim 26, wherein the patient support comprises polypropylene.

29. The patient handling device of claim 1, wherein the patient support facilitates positioning of a portion of the patient's anatomy within the magnetic resonance imaging system from a standard medical bed.

30. The patient handling device of claim 1, wherein the patient support is sized to support a substantial portion of the patient's body.

31. A headgear configured to receive a head of a patient during magnetic resonance imaging, the headgear comprising:

at least one radio frequency transmit and/or receive coil; and

at least one first releasable securing mechanism configured to engage with a member attached to a magnetic resonance imaging system at a location such that when the at least one securing mechanism is engaged with the member the headgear is positioned within an imaging region of the magnetic resonance imaging system.

32. The helmet of claim 31, wherein the at least one first releasable securing mechanism comprises:

a receiving portion sized to receive the member; and

a retaining portion configured to inhibit movement of the member once the member has been positioned within the receiving portion.

33. The helmet of claim 31, wherein the retaining portion comprises a first arm and a second arm, the first arm and the second arm each forming at least a portion of the receiving portion, the first arm comprising a first protrusion, and the second arm comprising a second protrusion, wherein the first protrusion and the second protrusion are configured to block the member from entering or exiting the receiving portion such that a force on the first protrusion and the second protrusion is required to allow the member to enter or exit the receiving portion.

34. The helmet of claim 33, wherein the first protrusion and the second protrusion are configured such that a first force required to allow the member to enter the receptacle is less than a second force required to allow the member to exit the receptacle.

35. The helmet of claim 33, wherein the member comprises a first portion having a first diameter and a second portion having a second diameter smaller than the first diameter, and the first arm and the second arm are configured to be positioned below the first portion and to clamp the second portion when the retaining portion is engaged with the member.

36. The helmet of claim 31, wherein the releasable securing mechanism allows the helmet to rotate about the member.

37. The helmet of claim 36, further comprising a second securing mechanism configured to prevent the helmet from rotating about the member when the second securing mechanism is engaged with the member.

38. The helmet of claim 37, wherein the member comprises at least one recess, and the second securing mechanism is configured to fit within the at least one recess to prevent the helmet from rotating about the member when the second securing mechanism is engaged with the at least one recess.

39. The helmet of claim 31, wherein at least a portion of the helmet comprises a see-through material such that the patient's head is visible through the helmet when the patient's head is positioned within the helmet.

40. The helmet of claim 39, wherein at least a portion of the helmet comprises a transparent material.

41. The helmet of claim 39, wherein at least a portion of the helmet comprises a translucent material.

42. A headgear configured to receive a head of a patient during magnetic resonance imaging, the headgear comprising:

at least one radio frequency transmit and/or receive coil;

at least one first releasable securing mechanism configured to engage with a member of the magnetic resonance imaging system such that when the at least one securing mechanism is engaged with the member, the at least one securing mechanism prevents translation of the headgear relative to the member but allows rotation of the headgear about the member; and

at least one second securing mechanism configured to prevent rotation of the helmet about the member when engaged with the cooperating portion of the member.

43. The helmet of claim 42, wherein the cooperating portion of the member comprises at least one recess, and the second securing mechanism is configured to fit within the at least one recess to prevent the helmet from rotating about the member when the second securing mechanism is engaged with the at least one recess.

44. The helmet of claim 43, wherein the at least one second securing mechanism comprises a pin, and the at least one recess comprises at least one indentation configured to receive the pin.

45. The helmet of claim 42, wherein the at least one first releasable securing mechanism comprises:

a receiving portion sized to receive the member; and

a retaining portion configured to inhibit movement of the member once the member has been positioned within the receiving portion.

46. The helmet of claim 42, wherein the retaining portion comprises a first arm and a second arm, the first arm and the second arm each forming at least a portion of the receiving portion, the first arm comprising a first protrusion and the second arm comprising a second protrusion, and the first protrusion and the second protrusion configured to block the member from entering and exiting the receiving portion such that a force on the first protrusion and the second protrusion is required to allow the member to enter and exit the receiving portion.

47. The helmet of claim 46, wherein the first protrusion and the second protrusion are configured such that a first force required to allow the member to enter the receptacle is less than a second force required to allow the member to exit the receptacle.

48. The helmet of claim 46, wherein the member comprises a first portion having a first diameter and a second portion having a second diameter smaller than the first diameter, and the first arm and the second arm are configured to be positioned below the first portion and to clamp the second portion when the retaining portion is engaged with the member.

49. The helmet of claim 42, wherein the releasable securing mechanism allows the helmet to rotate about the member.

50. The helmet of claim 42, wherein at least a portion of the helmet comprises a see-through material such that the patient's head is visible through the helmet when the patient's head is positioned within the helmet.

51. The helmet of claim 50, wherein at least a portion of the helmet comprises a transparent material.

52. The helmet of claim 50, wherein at least a portion of the helmet comprises a translucent material.

53. A magnetic resonance imaging system capable of imaging a patient supported at least in part by a support comprising a ferromagnetic material, the magnetic resonance imaging system comprising:

at least one first B₀A magnet for generating B for the magnetic resonance imaging system₀A first magnetic field to which the magnetic field contributes;

at least one second B₀A magnet for generating B for the magnetic resonance imaging system₀A second magnetic field to which the magnetic field contributes, the at least one first B₀Magnet and the at least one second B₀The magnets are arranged relative to each other such that at the at least one first B₀Magnet and the at least one second B₀An imaging area is provided between the magnets; and

a member configured to engage with a releasable securing mechanism of a radio frequency coil device, the member being at the at least one first B₀Magnet and the at least one second B₀The magnet is attached to the magnetic resonance imaging system substantially at a location within the imaging region where the radio frequency coil apparatus is secured to the magnetic resonance imaging system when the member is engaged with the releasable securing mechanism of the radio frequency coil apparatus.

54. The magnetic resonance imaging system of claim 53, wherein the member is attached to the at least one second B₀A magnet.

55. The magnetic resonance imaging system of claim 54, wherein the member includes a first portion having a first diameter and a second portion having a second diameter greater than the first diameter.

56. A magnetic resonance imaging system according to claim 55, wherein the first diameter is selected such that the member can fit within a receptacle of a releasable securing mechanism of the radio frequency coil device.

57. The system of claim 56, wherein a height of the first portion of the member is configured to allow at least a portion of the releasable securing mechanism forming the receptacle to fit under a second portion of the member.

58. The magnetic resonance imaging system of claim 55, wherein the second portion of the member includes at least one recess configured to receive a securing mechanism of the radio frequency coil apparatus to prevent rotation of the radio frequency coil apparatus about the member.

59. The magnetic resonance imaging system of claim 53, wherein B is₀The magnetic field has a magnetic field strength of less than or equal to 0.2 tesla, i.e. 0.2T, and greater than or equal to 20 mT.

60. The magnetic resonance imaging system of claim 59, wherein B is₀The magnetic field has a magnetic field strength of less than or equal to 0.1T and greater than or equal to 50 mT.

61. A magnetic resonance imaging system capable of imaging a patient supported at least in part by a support comprising a ferromagnetic material, the magnetic resonance imaging system comprising:

at least one first B₀A magnet for generating B for the magnetic resonance imaging system₀A first magnetic field to which the magnetic field contributes;

at least one second B₀A magnet for generating B for the magnetic resonance imaging system₀A second magnetic field to which the magnetic field contributes, the at least one first B₀Magnet and the at least one second B₀The magnets are arranged relative to each other such that at the at least one first B₀Magnet and the at least one second B₀An imaging area is provided between the magnets; and

a member configured to releasably secure with a patient handling deviceA member configured for securing a radio frequency coil device, the member being at the at least one first B₀Magnet and the at least one second B₀A magnet is attached to the magnetic resonance imaging system at a location such that the radio frequency coil secured to the patient handling device is positioned substantially within the imaging region when the member is engaged with the releasable securing mechanism of the patient handling device.

62. The magnetic resonance imaging system of claim 61, wherein the member is attached to the at least one second B₀A magnet.

63. The magnetic resonance imaging system of claim 62, wherein the member includes a first portion having a first diameter and a second portion having a second diameter greater than the first diameter.

64. The magnetic resonance imaging system of claim 63, wherein the first diameter is selected such that the member can fit within a receptacle of a releasable securing mechanism of the patient handling device.

65. The magnetic resonance imaging system of claim 63, wherein the height of the first portion of the member is configured to allow at least a portion of the releasable securing mechanism forming the receptacle to fit under the second portion of the member.

66. The magnetic resonance imaging system of claim 61, wherein B is₀The magnetic field has a magnetic field strength of less than or equal to 0.2 tesla, i.e. 0.2T, and greater than or equal to 20 mT.

67. The MRI system of claim 66, wherein B is greater than B₀The magnetic field having a value less than or equal to 0.1T and greater than or equal to 50mTMagnetic field strength.

68. A method, comprising:

a support is releasably secured to the magnetic resonance imaging apparatus to facilitate magnetic resonance imaging of the patient, wherein the support is disposed between the patient and a standard medical bed.

69. The method of claim 68, wherein the standard medical bed includes at least some ferromagnetic material.

70. A method, comprising:

positioning a portion of a patient's anatomy within an imaging region of a magnetic resonance imaging system while the patient is at least partially supported by a standard medical bed; and

acquiring at least one magnetic resonance image of a portion of the patient's anatomy while the patient is at least partially supported by the standard medical bed.

71. The method of claim 70, wherein the standard medical bed includes at least some ferromagnetic material.

72. An apparatus for imaging a foot, the apparatus comprising:

at least one housing configured to receive a patient's foot during magnetic resonance imaging;

at least one radio frequency transmit and/or receive coil; and

at least one first releasable securing mechanism configured to engage with a member attached to a magnetic resonance imaging system at a location such that when the at least one securing mechanism is engaged with the member the apparatus is positioned within an imaging region of the magnetic resonance imaging system.

73. The apparatus according to claim 72 wherein the at least one first releasable securing mechanism comprises:

a receiving portion sized to receive the member; and

a retaining portion configured to inhibit movement of the member once the member has been positioned within the receiving portion.

74. The apparatus of claim 72, wherein the holder comprises a first arm and a second arm, the first arm and the second arm each forming at least a portion of the receptacle, the first arm comprising a first protrusion and the second arm comprising a second protrusion, and the first protrusion and the second protrusion configured to block the member from entering and exiting the receptacle such that a force on the first protrusion and the second protrusion is required to allow the member to enter and exit the receptacle.

75. The apparatus of claim 74, wherein the first protrusion and the second protrusion are configured such that a first force required to allow the member to enter the receptacle is less than a second force required to allow the member to exit the receptacle.

76. The apparatus of claim 74, wherein the member includes a first portion having a first diameter and a second portion having a second diameter smaller than the first diameter, and the first arm and the second arm are configured to be positioned below the first portion and to clamp the second portion when the retaining portion is engaged with the member.

77. The apparatus of claim 72, wherein the releasable securing mechanism allows the apparatus to rotate about the member.

78. The apparatus of claim 77, further comprising a second securing mechanism configured to prevent the apparatus from rotating about the member when the second securing mechanism is engaged with the member.

79. The apparatus of claim 78, wherein the member includes at least one recess, the second securing mechanism configured to fit within the at least one recess when the second securing mechanism is engaged with the at least one recess to prevent rotation of the apparatus about the member.

80. The apparatus of claim 72, wherein the apparatus is tilted at an angle relative to a vertical axis.

81. The apparatus according to claim 80, wherein a foot axis of the apparatus has an angle of more than 15 degrees and less than 75 degrees with respect to the vertical axis towards the longitudinal axis.

82. The apparatus according to claim 81, wherein a foot axis of the apparatus has an angle with respect to the vertical axis towards a longitudinal axis that is greater than 30 degrees and less than 45 degrees.

83. The apparatus according to claim 80, wherein the foot axis of the apparatus has an angle greater than 5 degrees and less than 90 degrees with respect to the vertical axis towards the lateral axis.

84. The apparatus according to claim 83 wherein the foot axis of the apparatus has an angle greater than 15 degrees and less than 75 degrees with respect to the vertical axis toward the lateral axis.

85. The apparatus according to claim 84, wherein a foot axis of the apparatus has an angle of more than 30 degrees and less than 45 degrees with respect to the vertical axis towards a lateral axis.

86. The apparatus of claim 72, wherein the at least one transmit and/or receive coil comprises a plurality of receive coils.

87. The apparatus of claim 86, wherein at least one of the plurality of receive coils at least partially overlaps at least one other of the plurality of receive coils.

88. The apparatus of claim 86, wherein at least one of the plurality of receive coils is disposed vertically above at least another one of the plurality of receive coils.

89. The apparatus of claim 88, wherein at least one of the plurality of receive coils configured above at least another one of the plurality of receive coils is offset from at least another one of the plurality of receive coils in a horizontal direction.

90. An apparatus for imaging a foot, the apparatus comprising:

at least one radio frequency transmit and/or receive coil; and

at least one housing configured to receive a patient's foot during magnetic resonance imaging, the at least one housing being inclined at an angle relative to a vertical axis.

91. The apparatus according to claim 90, wherein a foot axis of the apparatus has an angle of more than 15 degrees and less than 75 degrees with respect to the vertical axis towards a longitudinal axis.

92. The apparatus according to claim 91, wherein a foot axis of the apparatus has an angle with respect to the vertical axis towards the longitudinal axis that is greater than 30 degrees and less than 45 degrees.

93. The apparatus according to claim 90, wherein a foot axis of the apparatus has an angle greater than 5 degrees and less than 90 degrees with respect to the vertical axis toward a lateral axis.

94. The apparatus according to claim 93, wherein a foot axis of the apparatus has an angle with respect to the vertical axis towards the lateral axis that is greater than 15 degrees and less than 75 degrees.

95. The apparatus according to claim 94, wherein a foot axis of the apparatus has an angle with respect to the vertical axis towards the lateral axis that is greater than 30 degrees and less than 45 degrees.

96. The apparatus of claim 90, further comprising at least one first releasable fixation mechanism configured to engage a member attached to a magnetic resonance imaging system at a location such that when the at least one fixation mechanism is engaged with the member, the apparatus is positioned within an imaging region of the magnetic resonance imaging system.

97. The apparatus according to claim 96, wherein the at least one first releasable securing mechanism comprises:

a receiving portion sized to receive the member; and

a retaining portion configured to inhibit movement of the member once the member has been positioned within the receiving portion.

98. The apparatus of claim 90, wherein the holder comprises a first arm and a second arm, the first arm and the second arm each forming at least a portion of the receptacle, the first arm comprising a first protrusion and the second arm comprising a second protrusion, and the first protrusion and the second protrusion configured to block the member from entering and exiting the receptacle such that a force on the first protrusion and the second protrusion is required to allow the member to enter and exit the receptacle.

99. The apparatus of claim 98, wherein the first protrusion and the second protrusion are configured such that a first force required to allow the member to enter the receptacle is less than a second force required to allow the member to exit the receptacle.

100. The apparatus of claim 98, wherein the member includes a first portion having a first diameter and a second portion having a second diameter smaller than the first diameter, and the first arm and the second arm are configured to be positioned below the first portion and to clamp the second portion when the retaining portion is engaged with the member.

101. The apparatus according to claim 90, wherein the releasable securing mechanism allows the apparatus to rotate about the member.

102. The apparatus of claim 101, further comprising a second securing mechanism configured to prevent the apparatus from rotating about the member when the second securing mechanism is engaged with the member.

103. The apparatus of claim 102, wherein the member includes at least one recess, and the second securing mechanism is configured to fit within the at least one recess when the second securing mechanism is engaged with the at least one recess to prevent rotation of the apparatus about the member.

104. The apparatus according to claim 90, wherein said at least one transmitting and/or receiving coil comprises a plurality of receiving coils.

105. The apparatus of claim 104, wherein at least one of the plurality of receive coils at least partially overlaps at least another one of the plurality of receive coils.

106. The apparatus of claim 104, wherein at least one of the plurality of receive coils is configured above at least another one of the plurality of receive coils in a vertical direction.

107. The apparatus of claim 106, wherein at least one of the plurality of receive coils configured above at least another of the plurality of receive coils is offset from at least another of the plurality of receive coils in a horizontal direction.

108. A bridge adapted for attachment to a magnetic resonance imaging system and configured to facilitate positioning of a patient within the magnetic resonance imaging system, the bridge comprising:

a support having a surface configured to support at least a portion of the patient, the support being movable between a cocked position and a lowered position, the surface being substantially vertical in the cocked position and substantially horizontal in the lowered position;

a hinge configured to allow the support to move from the cocked position to the lowered position and to allow the support to move from the lowered position to the cocked position; and

a base configured to attach the bridge to the magnetic resonance imaging system.

109. The bridge of claim 108, wherein the hinge comprises a pivot coupled to the support to allow the support to pivot between the raised position and the lowered position.

110. The bridge of claim 109, wherein the support comprises a groove and the pivot comprises a tongue inserted into the groove to couple the pivot to the support.

111. The bridge according to claim 110 wherein said tenon is comprised of a plastic material.

112. The bridge according to claim 110 wherein said strut members are comprised of a plastic material.

113. The bridge of claim 109, wherein the pivot comprises a first aperture and the base comprises a second aperture, and the hinge further comprises a shaft inserted through the first aperture and the second aperture to couple the pivot to the base and allow the pivot to rotate about the shaft to pivot the support between the erect position and the down position.

114. The bridge according to claim 108 wherein a length of a surface of said support member is between 8 inches and 16 inches.

115. The bridge according to claim 108 wherein a width of a surface of said support member is between 12 inches and 30 inches.

116. The bridge of claim 108, wherein the bridge is rated for a 500 pound patient.

117. The bridge of claim 116, wherein the bridge has a safety factor of at least 2.5.

118. The bridge of claim 116, wherein a safety factor of the bridge is greater than or equal to 2.5 and less than or equal to 4.0.

119. The bridge of claim 116, wherein a safety factor of the bridge is greater than or equal to 2.5 and less than or equal to 4.3.

120. The bridge of claim 108, wherein the base comprises a plurality of holes configured to allow screwing of the bridge to the magnetic resonance imaging system.

121. The bridge according to claim 120 wherein at least the portion of said base including said plurality of holes is made of steel.

122. The bridge of claim 120, wherein the bridge is bolted to B of the magnetic resonance imaging system₀A magnet.

123. The bridge of claim 109, further comprising a counterbalance mechanism that inhibits pivoting of the support member from the cocked position to the lowered position.

124. The bridge according to claim 123 wherein said counterbalance mechanism comprises at least one torsion spring that resists pivoting of said support member from said cocked position to said lowered position.

125. The bridge according to claim 124 wherein said at least one torsion spring is coupled to said pivot such that when said pivot is rotated, said at least one torsion spring slows the rate at which said support is pivoted from said cocked position to said lowered position.

126. The bridge of claim 125, further comprising a lock switch configured to disable motor drive of the magnetic resonance imaging system when the lock switch is activated.

127. The bridge of claim 126, wherein the locking switch is configured to be activated when the support member is moved to the lowered position and additional weight is applied to the support member.

128. The bridge according to claim 126 wherein said locking switch is configured to be activated when said support member is placed in said lowered position.

129. The bridge of claim 126, wherein the locking switch comprises at least one sensor configured to detect when a patient is positioned on the support.

130. A magnetic resonance imaging system, comprising:

B₀a magnet configured to generate a magnetic field suitable for magnetic resonance imaging;

a transport mechanism configured to allow the magnetic resonance imaging system to move to different positions; and

a bridge configured to facilitate positioning of a patient within the magnetic resonance imaging system, the bridge comprising:

a support having a surface configured to support at least a portion of the patient, the support being movable between a cocked position and a lowered position, the surface being substantially vertical in the cocked position and substantially horizontal in the lowered position;

a hinge configured to allow the support to move from the cocked position to the lowered position and to allow the support to move from the lowered position to the cocked position; and

a base attaching the bridge to the magnetic resonance imaging system.

131. The magnetic resonance imaging system of claim 130, wherein the hinge includes a pivot coupled to the support to allow the support to pivot between the cocked position and the lowered position.

132. The magnetic resonance imaging system of claim 130, wherein the support includes a groove and the pivot includes a tongue inserted into the groove to couple the pivot to the support.

133. The system of claim 132, wherein the tenon is constructed of a plastic material to reduce eddy currents generated in the bridge when the system is operated.

134. The magnetic resonance imaging system of claim 132, wherein the support is constructed of a plastic material.

135. The magnetic resonance imaging system of claim 131, wherein the pivot portion includes a first aperture and the base includes a second aperture, the hinge further including a shaft inserted through the first and second apertures to couple the pivot portion to the base and allow the pivot portion to rotate about the shaft to pivot the support between the cocked position and the lowered position.

136. The magnetic resonance imaging system of claim 130, wherein the surface of the support is between 8 inches and 16 inches in length.

137. The magnetic resonance imaging system of claim 130, wherein the surface of the support is between 12 inches and 30 inches wide.

138. The system of claim 130, wherein the bridge is rated for a 500 pound patient.

139. The magnetic resonance imaging system of claim 138, wherein the bridge has a safety factor of at least 2.5.

140. The magnetic resonance imaging system of claim 138, wherein the bridge has a safety factor greater than or equal to 2.5 and less than or equal to 4.0.

141. The magnetic resonance imaging system of claim 138, wherein the bridge has a safety factor greater than or equal to 2.5 and less than or equal to 4.3.

142. The magnetic resonance imaging system of claim 130, wherein the base includes a plurality of holes that receive respective bolts that attach the base to the magnetic resonance imaging system.

143. The magnetic resonance imaging system of claim 142, wherein at least the portion of the base including the plurality of holes is made of steel.

144. The magnetic resonance imaging system of claim 142, wherein the base of the bridge is bolted to B of the magnetic resonance imaging system₀A magnet.

145. The magnetic resonance imaging system of claim 131, wherein the bridge further comprises a counterbalance mechanism that inhibits pivoting of the support from the cocked position to the lowered position.

146. The magnetic resonance imaging system of claim 145, wherein the counterbalance mechanism includes at least one torsion spring that resists pivoting of the support from the cocked position to the lowered position.

147. The magnetic resonance imaging system of claim 146, wherein the at least one torsion spring is coupled to the pivot such that when the pivot is rotated, the at least one torsion spring slows a rate at which the support pivots from the cocked position to the lowered position.

148. A method of imaging a portion of a patient's anatomy with the patient supported at least in part by a standard medical bed, the method comprising:

positioning a magnetic resonance imaging system and the couch in proximity to each other;

moving a bridge attached to the magnetic resonance imaging system from a vertical position to a horizontal position in a manner that the bridge overlaps a portion of the bed;

positioning the patient via the bridge such that a portion of the patient's anatomy is within an imaging region of the magnetic resonance imaging system; and

acquiring at least one magnetic resonance image of a portion of the patient's anatomy while the patient is at least partially supported by the couch and at least partially supported by the bridge.

Background

Magnetic Resonance Imaging (MRI) provides an important imaging modality for many applications and is widely used in clinical and research environments to produce images of the interior of the human body. Generally, MRI is based on detecting Magnetic Resonance (MR) signals, which are electromagnetic waves emitted by atoms in response to state changes caused by an applied electromagnetic field. For example, Nuclear Magnetic Resonance (NMR) techniques involve detecting MR signals emitted from excited atomic nuclei as nuclear spins of atoms in an imaged body (e.g., atoms in human tissue) rearrange or relax. The detected MR signals may be processed to generate images that, in the context of medical applications, allow for the study of internal structures and/or biological processes within the body for diagnostic, therapeutic and/or research purposes.

MRI offers an attractive imaging modality for biological imaging due to the ability to produce non-invasive images with higher resolution and contrast and without the safety concerns of other modalities (e.g., without exposing the subject to ionizing radiation such as X-rays or introducing radioactive materials into the body). Furthermore, MRI is particularly suited to provide soft tissue contrast, which can be used to image subjects that cannot be satisfactorily imaged by other imaging modalities. In addition, MR techniques can capture information about structures and/or biological processes that cannot be acquired by other modalities. However, for a given imaging application, MRI suffers from a number of drawbacks, which may involve higher cost of equipment, limited availability, and/or difficulty in gaining access to the clinical MRI scanner and/or the length of the image acquisition process.

The trend in clinical MRI is to increase the field strength of MRI scanners to improve one or more of scan time, image resolution, and image contrast, which in turn continues to increase costs. Most installed MRI scanners operate at 1.5 or 3 tesla (T), which means the main magnetic field B₀Of the field strength of (a). A rough cost estimate for clinical MRI scanners is on the order of $ one million per tesla, which does not include the substantial operating, service, and maintenance costs involved in operating such MRI scanners.

In addition, conventional high-field MRI systems typically require large superconducting magnets and associated electronics to generate a strong, uniform static magnetic field (B) that images the imaged volume (e.g., a patient)₀). For a typical high-field MRI device that includes multiple chambers for the magnet, electronics, thermal management system, and console regions, the size of such a system is quite large. The size and expense of high-field MRI systems often limits their use to facilities such as hospitals and academic research centers that have sufficient space and resources to purchase and maintain them. The high cost and large space requirements of high-field MRI systems result in limited availability of MRI scanners. As such, there are many such clinical situations: MRI scanning would be beneficial, but is impractical or impossible due to one or more of the limitations discussed above, as discussed in further detail below.

Disclosure of Invention

Some embodiments include a patient handling apparatus configured to facilitate positioning of a patient within a magnetic resonance imaging device, the patient handling apparatus comprising: a patient support having a surface adapted to be positioned between the patient and a bed such that when the surface of the patient support is positioned, the surface of the patient support is below at least a portion of the patient's body; and a fixing portion including: at least one first releasable securing mechanism configured to engage with a radio frequency component to secure the radio frequency component to the securing portion; and at least one second releasable securing mechanism configured to engage with the magnetic resonance imaging device to secure the securing portion to the magnetic resonance imaging device.

Some embodiments include a headgear configured to receive a head of a patient during magnetic resonance imaging, the headgear comprising: at least one radio frequency transmit and/or receive coil; and at least one first releasable securing mechanism configured to engage a member attached to a magnetic resonance imaging system at a location such that when the at least one securing mechanism is engaged with the member the headgear is positioned within an imaging region of the magnetic resonance imaging system.

Some embodiments include a headgear configured to receive a head of a patient during magnetic resonance imaging, the headgear comprising: at least one radio frequency transmit and/or receive coil; at least one first releasable securing mechanism configured to engage with a member of the magnetic resonance imaging system such that when the at least one securing mechanism is engaged with the member, the at least one securing mechanism prevents translation of the headgear relative to the cooperating member; and at least one second securing mechanism configured to prevent rotation of the helmet about the member when engaged with the cooperating portion of the member.

Some embodiments include a magnetic resonance imaging system capable of imaging a patient supported at least in part by a support comprising a ferromagnetic material, the magnetic resonance imaging system comprising: at least one first B₀A magnet for generating B for the magnetic resonance imaging system₀First magnetic field to which magnetic field contributes, B₀The magnetic field has a field strength less than or equal to 0.2T; at least one second B₀A magnet for generating B for the magnetic resonance imaging system₀A second magnetic field to which the magnetic field contributes, the at least one first B₀Magnet and the at least one second B₀The magnets are arranged relative to each other such that at the at least one first B₀Magnet and the at least one second B₀An imaging area is provided between the magnets; and a member configured to engage with a releasable securing mechanism of the radio frequency coil device, the member being at the at least one first B₀Magnet and the at least one second B₀A magnet between the magnets at a location such that when the member is engaged with the releasable securing mechanism of the radio frequency coil apparatus, the radio frequency coil apparatus is attached to the magnetic resonance imaging system substantially within the imaging region at the location secured to the magnetic resonance imaging system.

Some embodiments include a magnetic resonance imaging system capable of imaging a patient supported at least in part by a support comprising a ferromagnetic material, the magnetic resonance imaging system comprising: at least one first B₀A magnet for generating B for the magnetic resonance imaging system₀First magnetic field to which magnetic field contributes, B₀The magnetic field has a field strength less than or equal to 0.2T; at least one second B₀A magnet for generating B for the magnetic resonance imaging system₀A second magnetic field to which the magnetic field contributes, the at least one first B₀Magnet and the at least one second B₀The magnets are arranged relative to each other such that at the at least one first B₀Magnet and the at least one second B₀An imaging area is provided between the magnets; and a member configured to engage with a releasable securing mechanism of a patient treatment apparatus configured to secure a radio frequency coil apparatus, the member being at the at least one first B₀Magnet and the at least one second B₀A magnet is attached to the magnetic resonance imaging at a location such that the radio frequency coil secured to the patient handling device is positioned substantially within the imaging region when the member is engaged with the releasable securing mechanism of the patient handling device.

Some embodiments include a method, comprising: a support is releasably secured to the magnetic resonance imaging apparatus to facilitate magnetic resonance imaging of the patient, wherein the support is disposed between the patient and a standard medical bed.

Some embodiments include a method, comprising: positioning a portion of a patient's anatomy (anatomi) within an imaging region of a magnetic resonance imaging system while the patient is at least partially supported by a standard medical bed; and acquiring at least one magnetic resonance image of a portion of the patient's anatomy while the patient is at least partially supported by the standard medical bed.

Some embodiments include an apparatus for imaging a foot, the apparatus comprising: at least one housing configured to receive a patient's foot during magnetic resonance imaging; at least one radio frequency transmit and/or receive coil; and at least one first releasable securing mechanism configured to engage with a member attached to the magnetic resonance imaging system at a location such that when the at least one securing mechanism is engaged with the member the apparatus is positioned within an imaging region of the magnetic resonance imaging system.

Some embodiments include an apparatus for imaging a foot, the apparatus comprising: at least one radio frequency transmit and/or receive coil; and at least one housing configured to receive a foot of a patient during magnetic resonance imaging, the at least one housing being inclined at an angle relative to a vertical axis.

Some embodiments include a bridge adapted to be attached to a magnetic resonance imaging system and configured to facilitate positioning of a patient within the magnetic resonance imaging system, the bridge comprising: a support having a surface configured to support at least a portion of the patient, the support being movable between a cocked position and a lowered position, the surface being substantially vertical in the cocked position and substantially horizontal in the lowered position; a hinge configured to allow the support to move from the cocked position to the lowered position and to allow the support to move from the lowered position to the cocked position; and a base configured to attach the bridge to the magnetic resonance imaging system.

Some embodiments include a magnetic resonance imaging system comprising: b is₀A magnet configured to generate a magnetic field suitable for magnetic resonance imaging; a transport mechanism configured to allow the magnetic resonance imaging system to move to different positions; and a bridge configured to facilitate positioning of a patient within the magnetic resonance imaging system, the bridge comprising: a support having a surface configured to support at least a portion of the patient, the support being movable between a cocked position and a lowered position, the surface being substantially vertical in the cocked position and substantially horizontal in the lowered position; a hinge configured to allow the support to move from the cocked position to the lowered position and to allow the support to move from the lowered position to the cocked position; and a base attaching the bridge to the magnetic resonance imaging system.

Some embodiments include a method of imaging a portion of a patient's anatomy with the patient supported at least in part by a standard medical bed, the method comprising: positioning a magnetic resonance imaging system and the couch in proximity to each other; moving a bridge attached to the magnetic resonance imaging system from a vertical position to a horizontal position in a manner that the bridge overlaps a portion of the bed; positioning the patient via the bridge such that a portion of the patient's anatomy is within an imaging region of the magnetic resonance imaging system; and acquiring at least one magnetic resonance image of a portion of the patient's anatomy while the patient is at least partially supported by the couch and at least partially supported by the bridge.

Drawings

Various aspects and embodiments of the disclosed technology will be described with reference to the following drawings. It should be understood that the drawings are not necessarily drawn to scale.

Figure 1 shows exemplary components of a magnetic resonance imaging system;

fig. 2A and 2B illustrate a portable low-field MRI system according to some embodiments.

FIG. 3 illustrates a portable MRI system according to some embodiments;

4A-4I illustrate a patient handling device that facilitates MRI of a patient from a standard hospital bed, according to some embodiments;

fig. 5A-5F illustrate aspects of a fixation portion of a patient treatment device according to some embodiments;

6A-6B illustrate a releasable securing mechanism according to some embodiments;

figures 7A-7B illustrate aspects of a releasable securing mechanism of a radio frequency coil device according to some embodiments.

Figures 8A-8B illustrate aspects of a releasable securing mechanism of a radio frequency coil device according to some embodiments;

fig. 9A-9B illustrate a perspective radio frequency helmet according to some embodiments;

10-10D illustrate views of a foot coil according to some embodiments;

FIG. 11 illustrates a foot coil configured to accommodate a wider foot, according to some embodiments; and

12A-12D illustrate a foot coil positioned within a magnetic resonance imaging device, according to some embodiments;

fig. 13A illustrates a folding bridge, according to some embodiments, shown in an upright or erect position;

fig. 13B illustrates the folding bridge shown in fig. 13A in a horizontal or lowered position according to some embodiments.

Fig. 14 illustrates components of a folding bridge according to some embodiments;

fig. 15A illustrates a model of a bridge according to some embodiments;

FIG. 15B illustrates a stress map of a model of the bridge illustrated in FIG. 15A;

fig. 15C shows a deflection diagram of a model of the bridge shown in fig. 15A.

FIG. 15D is a graph A.19 from IEC 60601-1 showing the body mass distribution of a patient support surface;

fig. 16A and 16B illustrate components of a folding bridge with a balancing mechanism (counter-balance mechanism), according to some embodiments;

FIG. 17A shows a portable MRI system with a bridge in an upright position;

FIG. 17B shows a portable MRI system with the bridge in a horizontal position;

figure 17C shows a patient positioned within the portable MRI system and supported by the folding bridge.

Detailed Description

The MRI scanner market is overwhelmingly dominated by high field systems, and particularly in medical or clinical MRI applications. As mentioned above, the general trend in medical imaging is to produce MRI scanners with increasingly higher field strengths, with the vast majority of clinical MRI scanners operating at 1.5T or 3T, while higher field strengths of 7T and 9T are used in research environments. Although clinical systems operating between 0.5T and 1.5T are also commonly referred to as "high-field," as used herein, "high-field" generally refers to MRI systems currently used in clinical settings, and more particularly, to main magnetic fields (i.e., B) above 1.5T (i.e., B;)₀Field) operated MRI system. A field strength between about 0.2T and 0.5T is called "midfield" and as the field strength continues to increase in the high-field state, a field strength in the range between 0.5T and 1T is also called midfield. In contrast, as a result of the high end field strength increase of the high field state, albeit at times, will have a B between 0.2T and about 0.3T₀The system of fields is referred to as low field, but "low field" generally refers to B at less than or equal to about 0.2T₀A field operated MRI system. In the low field state, with B less than.1T₀Low-field MRI systems operating with fields are referred to herein as "very low fields," with B less than 10mT₀A field operated low-field MRI system is referred to herein as an "ultra-low field".

As described above, the conventional MRI system requires a special facility. MRI systems require electromagnetically shielded rooms to operate, and the floor of the room must be structurally reinforced. Additional space must be provided for high power electronics and control areas for the scan technician. It must also provide secure access to the premises. Furthermore, dedicated three-phase electrical connections must be installed to provide power to the electronics, which in turn are cooled by the supply of cooling water. Additional HVAC capacity must also typically be provided. These site requirements are not only costly, but also greatly limit the locations where MRI systems can be deployed. Conventional clinical MRI scanners also require a great deal of expertise to operate and maintain. These trained technicians and maintenance engineers add significant ongoing operating costs to the operation of the MRI system. As a result, conventional MRI is often costly and severely limited in accessibility, which makes MRI an unavailable and widely used diagnostic tool that can provide a wide range of clinical imaging solutions anytime and anywhere. Typically, a patient must visit one of a limited number of facilities at a pre-scheduled time and place, which makes MRI unusable for many medical applications where MRI has unique effectiveness in assisting diagnosis, surgery, patient monitoring, and the like.

As mentioned above, high-field MRI systems require specially adapted facilities to accommodate the size, weight, power consumption, and shielding requirements of these systems. For example, 1.5T MRI systems typically weigh between 4 and 10 tons, while 3T MRI systems typically weigh between 8 and 20 tons. In addition, high-field MRI systems typically require a large amount of heavy and expensive shielding. Many mid-field scanners are even heavier, weighing between 10 and 20 tons, in part because of the use of very large permanent magnets and/or yokes. B generation due to high use of ferromagnetic materials₀Field, increased shield tonnage, so commercially available low field MRI systems (e.g., B at 0.2T)₀Magnetic field operation) is also typically in the range of 10 tons or more. To accommodate such heavy equipment, rooms (typically 30 to 50 square meters in minimum size) must be built using a laminate floor (e.g., a concrete floor) and must be specially shielded to prevent electromagnetic radiation from interfering with the operation of the MRI system. Thus, available clinical MRI systems are not mobile and require large dedicated spaces in a hospital or facility, requiring operation and, in addition to the significant cost of space to prepare for workAdditional ongoing costs for professionals who maintain the system.

Furthermore, currently available MRI systems typically consume a large amount of power. For example, conventional 1.5T and 3T MRI systems typically consume between 20 and 40kW of power during operation, whereas available 0.5T and 0.2T MRI systems typically consume between 5 and 20kW of power, each using a dedicated and dedicated power supply. Unless otherwise stated, power consumption refers to the average power consumption over a time interval of interest. For example, the 20 to 40kW mentioned above represents the average power consumed by a conventional MRI system during image acquisition, which may include relatively short periods of peak power consumption (e.g., when the gradient coils and/or RF coils are pulsed within relatively short pulse sequence periods) that significantly exceed the average power consumption. The separation of peak (or large) power consumption is typically addressed via the power storage element (e.g., capacitor) of the MRI system itself. Thus, the average power consumption is a more relevant figure, as it generally determines the type of power connection required to operate the device. As mentioned above, available clinical MRI systems must have a dedicated power supply, typically requiring a dedicated three-phase connection to the power grid to power the components of the MRI system. Additional electronics are then required to convert the three-phase power to single-phase power for use by the MRI system. The many physical requirements of deploying conventional clinical MRI systems pose significant problems of usability and severely limit the clinical applications in which MRI can be utilized.

Thus, many of the requirements of high-field MRI make it impossible to install in many cases, limiting their deployment to large institutional hospitals or specialized facilities, and often limiting their use to strictly scheduled appointments, which require patients to visit dedicated facilities at pre-scheduled times. Thus, many limitations on high-field MRI have prevented MRI from being used entirely as an imaging modality. Despite the above-mentioned shortcomings of high-field MRI, the significantly increased attractiveness of SNR at higher fields continues to push the industry to use increasingly higher field strengths in clinical and medical MRI applications, which further increases the cost and complexity of MRI scanners and further limits their availability and makes them unusable as general and/or commonly used imaging solutions.

The low SNR of MR signals generated in low-field areas, particularly in very low-field areas, has hindered the development of relatively low-cost, low-power and/or portable MRI systems. Conventional "low-field" MRI systems operate at a high end, often referred to as the low-field region (e.g., the lower limit of clinically available low-field systems is about 0.2T), to acquire useful images. Although somewhat less expensive than high-field MRI systems, conventional low-field MRI systems suffer from many of the same drawbacks. In particular, conventional low-field MRI systems are large, stationary and immobile installations, consume a large amount of power (requiring dedicated three-phase power connections), and require specially shielded rooms and large dedicated spaces. The challenges of low-field MRI prevent the development of relatively low-cost, low-power, and/or portable MRI systems that are capable of producing useful images.

The inventors have developed techniques that enable portable, low-field, low-power, and/or low-cost MRI systems that can improve the large-scale deployments of MRI technology in a variety of environments outside of current MRI facilities at hospitals and research facilities. As a result, MRI can be deployed in emergency rooms, mini-clinics, doctor's offices, mobile devices, the field, and the like, and can be taken to the patient (e.g., bedside) to perform a wide variety of imaging procedures and protocols. Some embodiments include extremely low-field MRI systems (e.g., 0.1T, 50mT, 20mT, etc.) that facilitate portable, low-cost, low-power MRI, thereby significantly increasing MRI availability in a clinical setting.

There are a number of challenges to developing clinical MRI systems in the low-field domain. As used herein, the term "clinical MRI system" refers to an MRI system that produces clinically useful images, which refers to images having sufficient resolution and sufficient acquisition time to be available to a physician or clinician for their intended purpose given a particular imaging application. Thus, the resolution/acquisition time of the clinically useful image will depend on the purpose for which the image is obtained.

One of the many challenges in obtaining clinically useful images in low-field areas is the relatively low SNR. Specifically, SNR and B₀The relation between the field strengths is 0.2T toAt a field strength of about B₀ ^5/4And about B at field strengths below 0.1T₀ ^3/2. Thus, the SNR drops significantly with decreasing field strength, with the magnitude of the SNR drop being even more pronounced at very low field strengths. The significant decrease in SNR due to the reduced field strength is an important factor that hinders the development of clinical MRI systems in extremely low field regions. In particular, the challenge of low SNR at very low field strengths has hindered the development of clinical MRI systems operating in very low field areas. As a result, clinical MRI systems that attempt to operate at lower field strengths have conventionally achieved field strengths in the range above about 0.2T. These MRI systems are still large, heavy and expensive, often requiring a fixed dedicated space (or shielded tent) and a dedicated power supply.

The inventors have developed low-field and very low-field MRI systems capable of producing clinically useful images, allowing the development of portable, low-cost and easy-to-use MRI systems that cannot be achieved using existing techniques. According to some embodiments, generally, an MRI system may be delivered to a patient to provide a wide variety of diagnostic, surgical, monitoring, and/or therapeutic procedures whenever and wherever desired. There are challenges in providing an MRI system that can be transported to a patient and/or operated outside of a specialized facility (e.g., outside of a safe and shielded room), many of which are addressed using the techniques described in U.S. patent No.10222434 entitled "portable magnetic resonance imaging method and apparatus" (hereinafter the "434 patent"), issued 3, 5, 2019, the entire contents of which are incorporated herein by reference.

Another challenge involves positioning the patient within the MRI system for imaging. As mentioned above, conventional MRI is limited to dedicated facilities including rooms for the apparatus itself, which are equipped with extensive shielding, and which must meet strict safety regulations, including the requirement that the room must be safe and free of ferrous materials due to the high field strengths involved with conventional clinical MRI. Standard hospital beds are constructed using ferrous materials (usually steel) which are prohibited from use with conventional clinical MRI systems. As a result, the patient must be taken to a specialized facility dedicated to the MRI system and transferred to a custom bed designed for use with the MRI system.

For ambulatory patients, this may mean that the patient is required to enter a safe room containing the MRI device and position themselves on an MRI safe bed integrated with the MRI device. For bedridden or other immobile patients, it may be desirable to transfer the patient first to a custom-made MRI safe couch to be transported to a safe room, and then to an integrated couch of the MRI system. Such requirements limit the environment in which a patient may perform MRI, and in some cases prohibit MRI altogether. For example, it is difficult to transfer a bedridden and/or immobile patient to an MRI safe bed or wheelchair to transport the patient to a safe room, and possibly again to an integrated bed or patient support of the MRI system, which in some circumstances is not feasible for medical safety reasons. In addition, MRI safety beds are expensive and not widely used.

The inventors have developed techniques that allow MRI to be performed in conjunction with standard patient supports, such as standard hospital beds or standard wheelchairs, thereby eliminating the need for one or more transfers of the patient, as well as eliminating the cost and usability issues associated with dedicated MRI safe transport (e.g., beds, wheelchairs, etc.). Furthermore, techniques that allow MRI to be performed, for example, from a standard hospital bed, facilitate point-of-care MRI (point-of-care MRI). According to some embodiments, MRI is performed at sufficiently low field strengths to allow imaging of a patient positioned on or in a standard patient support (e.g., a patient lying on a standard hospital bed or sitting in a standard wheelchair). As used herein, a standard hospital bed or standard wheelchair refers to a patient support that has not been equipped for conventional high-field MRI. Standard hospital beds or wheelchairs will typically be constructed of ferromagnetic materials (such as steel) that cannot be used for high-field MRI.

To image a patient from, for example, a standard hospital bed, a particular MRI imaging procedure may require positioning a target anatomy of the patient within an MRI system that is moved to a location such as the bed where the patient is currently lying. The inventors have developed techniques for facilitating positioning of a patient within an MRI system to image a desired anatomy of the patient. According to some embodiments, a patient handling system, which may be secured to the MRI system, is used to support the patient and position the desired anatomy of the patient within the MRI system.

Conventional MRI systems typically include an integrated couch or support for the patient that is constructed using non-ferrous materials to meet stringent regulatory requirements (e.g., regulations enacted to ensure safety of the patient and clinician) and that does not interfere with the magnetic field generated by the MRI system. The custom MRI safety bed is typically configured to slide into and out of the bore of the system, and typically has a cradle that allows the appropriate radio frequency coil device to be attached over the portion of the anatomy to be imaged. When the patient is prepared for imaging, the patient is positioned on the bed outside the magnet bore in such a way that the radio frequency coil device can be positioned and attached to a cooperating support on the bed. For example, for brain scanning, a radio frequency head coil device is positioned around the head of a patient and attached to a cooperative support secured to a bed. After the radio frequency coil device is attached and properly positioned, the bed is moved to B₀Inside the magnet such that the portion of the anatomy to be imaged is positioned within an image region of the MRI system.

The inventors have realized that this conventional procedure is not suitable for portable or point-of-care MRI, nor can it be used to image patients from a standard hospital bed or wheelchair. For example, a standard medical bed is not equipped with a bracket to which a radio frequency coil device may be attached, nor is it equipped with a radio frequency coil device configured to be attached to a standard medical bed. Furthermore, a standard hospital bed or wheelchair cannot be positioned within the imaging region of the MRI system. To facilitate imaging from, for example, a standard medical bed, the inventors have developed a radio frequency coil apparatus adapted to receive a target anatomy of a patient and configured to engage with a cooperating member attached to an MRI system such that when the radio frequency coil apparatus is engaged with the member, the target anatomy is positioned within an imaging region of the MRI system. In this way, the radio frequency coil device may be positioned around a patient and then attached to a portable MRI system so that the patient may be imaged from a standard hospital bed or wheelchair so that the MRI system may be brought to the patient or the patient may be pushed to and imaged from an available MRI system. Such point-of-care MRI allows MRI to be used in a wide variety of medical situations where conventional MRI is not available (e.g., in emergency rooms, intensive care units, operating rooms, etc.).

According to some embodiments, a radio frequency helmet comprising one or more radio frequency coils is adapted to receive a head of a patient. The radio frequency helmet includes a releasable securing mechanism configured to secure the helmet to a member attached to the MRI system at a location such that the helmet is substantially within an imaging region of the MRI system whenever the radio frequency helmet is secured to the member. In particular, when the helmet receives the head of the patient and is secured to the member, the head of the patient is located within the imaging region of the MRI system. According to some embodiments, a radio frequency coil device comprising one or more radio frequency coils adapted to receive an extremity such as a leg or arm is provided with such a releasable securing mechanism such that when the radio frequency coil device is secured to the member, the radio frequency coil device is substantially within the imaging region of the MRI system, thereby imaging the located extremity.

FIG. 1 is a block diagram of typical components of an MRI system 100. In the illustrative example of fig. 1, the MRI system 100 includes a computing device 104, a controller 106, a pulse sequence memory 108, a power management system 110, and a magnetic component 120. It should be understood that system 100 is illustrative and that an MRI system may have one or more other components of any suitable type in addition to or instead of the components shown in fig. 1. However, while the implementation of these components may vary greatly for a particular MRI system, the MRI system will typically include these advanced components, as discussed in further detail below.

As shown in FIG. 1, the magnetic member 120 includes B₀A magnet 122, shim coils 124, RF transmit and receive coils 126, and gradient coils 128. The magnet 122 may be used to generate a main magnetic field B₀. The magnet 122 may be capable of generating a desired main magnetic field B₀Any suitable type of magnetic component or combination of magnetic components. As described above, in the high field region, B₀Magnets are commonly used that are generally provided in a solenoid geometrySuperconducting material formation, which requires a cryogenic cooling system to convert B₀The magnet is maintained in a superconducting state. Thus, high field B₀Magnets are expensive, complex, and consume a large amount of power (e.g., cryogenic cooling systems require a large amount of power to sustain B₀The very low temperatures required to maintain the magnets in a superconducting state), large dedicated space, and specialized dedicated electrical connections (e.g., dedicated three-phase power connections to the power grid). Conventional low field B₀Magnet (e.g., B operating at 0.2T)₀Magnets) are also often implemented using superconducting materials, and therefore have these same general requirements. Other conventional low field B₀The magnets are implemented using permanent magnets for generating field strengths limited to conventional low-field systems (e.g., between 0.2T and 0.3T due to the inability to obtain useful images at lower field strengths), which need to be very large magnets weighing 5 to 20 tons. Thus, only B of the conventional MRI system₀The magnet both hinders portability and reduces affordability.

The gradient coil 128 may be configured to provide a gradient field, and may be configured, for example, in three substantially orthogonal directions (X, Y, Z) at B₀A gradient is generated in the field. The gradient coil 128 may be configured to systematically vary B₀The field (B generated by the magnet 122 and/or shim coils 124₀Fields) to encode the transmitted MR signals as a function of frequency or phase. For example, the gradient coils 128 may be configured to vary frequency or phase as a linear function of spatial position along a particular direction, although more complex spatial encoding profiles may be provided by using non-linear gradient coils. For example, a first gradient coil may be configured to selectively vary B in a first (X) direction₀The second gradient coil may be configured to selectively vary B in a second (Y) direction substantially perpendicular to the first direction₀The field is phase encoded, and the third gradient coil can be configured to selectively vary B in a third (Z) direction substantially perpendicular to the first and second directions₀Field to provide slice selection for volumetric imaging applicationsAnd (6) selecting. As mentioned above, conventional gradient coils also consume a significant amount of power, typically operated by large, expensive gradient power supplies, as discussed in further detail below.

MRI is performed by exciting and detecting the transmitted MR signals using transmit and receive coils, commonly referred to as Radio Frequency (RF) coils, respectively. The transmit/receive coil may comprise a single coil for transmitting and receiving, multiple coils for transmitting and/or receiving, or the same coil for transmitting and receiving. Thus, the transmit/receive components may include one or more coils for transmitting, one or more coils for receiving, and/or one or more coils for transmitting and receiving. The transmit/receive coils are also commonly referred to as Tx/Rx or Tx/Rx coils, and generally refer to various configurations of the transmit and receive magnetic components of the MRI system. These terms are used interchangeably herein. In FIG. 1, the RF transmit and receive coil 126 includes coils operable to generate RF pulses to induce an oscillating magnetic field B₁The one or more transmit coils of (a). The one or more transmit coils may be configured to generate any suitable type of RF pulse.

The power management system 110 includes electronics that provide operating power to one or more components of the low-field MRI system 100. For example, as discussed in more detail below, the power management system 110 may include one or more power supplies, gradient power components, transmit coil components, and/or any other suitable power electronics necessary to provide suitable operating power to energize and operate components of the MRI system 100. As shown in fig. 1, power management system 110 includes a power supply 112, one or more power components 114, a transmit/receive switch 116, and a thermal management component 118 (e.g., a cryogenic cooling apparatus for a superconducting magnet). The power supply 112 includes electronics that provide operating power to the magnetic components 120 of the MRI system 100. For example, the power supply 112 may include one or more B' s₀Coil (e.g. B)₀Magnet 122) provides the electronics that operate to generate the main magnetic field for the low-field MRI system. The transmit/receive switch 116 may be used to select whether the RF transmit coil or the RF receive coil is being operated.

The one or more power components 114 may include: one or more RF receive (Rx) preamplifiers that amplify MR signals detected by one or more RF receive coils (e.g., coil 126); one or more RF transmit (Tx) power components configured to provide power to one or more RF transmit coils (e.g., coil 126); one or more gradient power components configured to provide power to one or more gradient coils (e.g., gradient coil 128); and one or more shim power components configured to provide power to one or more shim coils (e.g., shim coil 124).

In conventional MRI systems, the electrical components are large, expensive, and consume a large amount of power. Typically, the power electronics occupy a separate room from the MRI scanner itself. Not only do power electronics require a large amount of space, but they are expensive, complex devices that consume a large amount of power and require a wall-mounted rack for support. Thus, the power electronics of conventional MRI systems also hinder portability and affordability of MRI.

As shown in fig. 1, the MRI system 100 includes a controller 106 (also referred to as a console), the controller 106 having control electronics to send instructions to the power management system 110 and receive information from the power management system 110. The controller 106 may be configured to implement one or more pulse sequences for determining instructions to send to the power management system 110 to operate the magnetic component 120 in a desired sequence (e.g., parameters for operating the RF transmit and receive coils 126, parameters for operating the gradient coils 128, etc.). As shown in fig. 1, the controller 106 also interacts with the computing device 104 programmed to process the received MR data. For example, the computing device 104 may process the received MR data to generate one or more MR images using any suitable image reconstruction process or processes. The controller 106 may provide information regarding the one or more pulse sequences to the computing device 104 for processing of data by the computing device. For example, the controller 106 may provide information regarding one or more pulse sequences to the computing device 104, and the computing device may perform image reconstruction processing based at least in part on the provided information. In conventional MRI systems, the computing device 104 typically includes one or more high-performance workstations configured to relatively quickly perform computationally expensive processing of the MR data. Such computing devices are themselves relatively expensive devices.

From the foregoing, it should be appreciated that currently available clinical MRI systems (including high-field, mid-field, and low-field systems) are large, expensive, stationary devices requiring a large amount of dedicated and specially designed space and dedicated power connections. As noted above, the inventors have developed a low-power, portable low-field MRI system that can be deployed in almost any environment and can be brought to a patient about to undergo an imaging procedure. In this way, patients in emergency rooms, intensive care units, operating rooms, and many other locations may benefit from MRI where MRI is not conventionally available. The exemplary portable MRI system described below in connection with fig. 2A, 2B, and 3A can be moved to a location where MRI is needed (e.g., emergency and operating rooms, primary care rooms, newborn rooms, intensive care rooms, specialty departments, patient rooms, recovery rooms, etc.) to facilitate point-of-care MRI operations in proximity to standard hospital equipment such as hospital beds, wheelchairs, other medical devices, computing equipment, life support systems, etc. In addition, the exemplary portable MRI system described herein, including the system illustrated in the' 434 patent, allows deployment of the MRI system in almost any location, such that a patient may be easily taken to the MRI system (e.g., transported using a standard hospital bed or wheelchair) to achieve point-of-care MRI.

Fig. 2A and 2B illustrate a low power portable low-field MRI system according to some embodiments. The portable MRI system 200 includes B₀Magnet 205, B₀The magnet 205 includes at least one first permanent magnet 210a and at least one second permanent magnet 210b magnetically coupled to each other by a ferromagnetic yoke 220, the ferromagnetic yoke 220 being configured to capture and direct magnetic flux to increase magnetic flux density within an imaging region (field of view) of the MRI system. The permanent magnets 210a and 210b may be constructed using any suitable technique (e.g., using any of the techniques, designs, and/or materials described in the' 434 patent). The yoke 220 may also be constructed using any of the techniques described herein (e.g., using any of the techniques, designs, and/or materials described in the' 434 patent)Material). It should be understood that in some embodiments, an electromagnet may be used to form B₀A magnet 205 using any of the electromagnetic techniques described herein (e.g., using any of the techniques, designs, and/or materials described in the' 434 patent). B is₀The magnet 205 may be coupled with one or more other magnetic components, such as the gradient coils (e.g., x-, y-, and z-gradient coils) and/or any shim components (e.g., shim coils or permanent magnet shims), B, of the system₀The calibration coils, etc. are wrapped or encapsulated together in a housing 212.

B₀The magnet 205 may be coupled or attached or mounted to the base 250 by a positioning mechanism 290, such as a goniometric platform (an example of which is illustrated in the' 434 patent), such that B₀The magnet may be tilted (e.g., rotated about its center of mass) to provide tilt to accommodate the patient's anatomy as desired. In FIG. 2A, B₀The magnet is shown as horizontal without tilting, in FIG. 2B, B is shown₀The magnet is rotated to tilt the surface of the anatomy supporting the patient being scanned. The positioning mechanism 290 may be fixed to a support configured as a support B₀One or more load bearing structures of the base 250 of the weight of the magnet 205.

Except that for providing for support B₀In addition to the load bearing structure of the magnet, the base 250 also includes an interior space configured to house the electronics 270 needed to operate the portable MRI system 200. For example, the base 250 may house power components to operate the gradient coils (e.g., X, Y and Z) and the RF transmit/receive coils. The inventors have developed a low power, low noise and low cost gradient amplifier generally configured to properly power gradient coils in low field applications, designed to be relatively low cost, and configured for installation within the base of a portable MRI system (i.e., rather than having a static ground in a separate room of a fixed facility as is conventional). Examples of suitable power components for operating the gradient coils (e.g., the power components described in connection with fig. 20-34) are described in further detail below. According to some embodiments, power electronics for powering gradient coils of an MRI system when the system is idleThe device consumes less than 50W of power, whereas when the MRI system is operating (i.e. during image acquisition) the consumed power is between 100 and 300W. The base 250 may also house RF coil amplifiers (i.e., power amplifiers for operating the transmit/receive coils of the system), power supplies, consoles, power distribution units, and other electronics necessary to operate the MRI system, as described in further detail below.

According to some embodiments, the electronics 270 required to operate the portable MRI system 200 consume less than 1kW of power, in some embodiments less than 750W of power, and in some embodiments less than 500W of power (e.g., with permanent B)₀MRI system of magnet solution). Techniques for facilitating low power operation of an MRI device are discussed in further detail below. However, systems that consume more power may also be utilized, as aspects are not limited in this respect. The exemplary portable MRI system 200 shown in fig. 2A-2B may be powered via a single power connection 275, the single power connection 275 being configured to connect to a mains power supply, such as an outlet (e.g., a standard or large appliance outlet) that provides single-phase power. Thus, the portable MRI system may be plugged into and operated from a single available power outlet, eliminating the need for a dedicated power source (e.g., eliminating the need for a dedicated three-phase power source and eliminating the need for further power conversion electronics that convert the three-phase power to single-phase power for distribution to the respective components of the MRI system), and increasing the availability of the MRI system and the environment and location in which the portable MRI system may be used.

The portable MRI system 200 shown in fig. 2A and 2B also includes a transport mechanism 280, the transport mechanism 280 allowing the portable MRI system to be transported to different locations. The transport mechanism may include one or more components configured to facilitate movement of the portable MRI system to a location where MRI is desired, for example. According to some embodiments, the transport mechanism includes a motor 286 coupled to the drive wheel 284. In this manner, the transport mechanism 280 provides motorized assistance in transporting the MRI system 200 to a desired location. The transport mechanism 280 may also include a plurality of casters 282 to aid in support and stability and to facilitate transport.

According to some embodiments, the transport mechanism 280 includes a motorized assist device controlled using a controller (e.g., a joystick or other human manipulable controller) to guide the portable MRI system during transport to a desired location. According to some embodiments, the delivery mechanism includes a power assist component configured to detect when a force is applied to the MRI system and, in response, engage with the delivery mechanism to provide motorized assistance in the direction of the detected force. For example, the track 255 of the base 250 shown in fig. 2A and 2B may be configured to detect when a force is applied to the track (e.g., by a person pushing on the track) and engage with a transport mechanism to provide motorized assistance to drive the wheel in the direction of the applied force. As a result, the user may guide the portable MRI system with the assistance of the transport mechanism in response to the direction of the force applied by the user. The power assist mechanism may also be provided with a safety mechanism for collisions. In particular, contact forces with other objects (e.g. walls, beds or other structures) may also be detected, and the transport mechanism will react accordingly in response to motorized movement away from the object. According to some embodiments, the motorized assistance may be eliminated and the portable MRI system may be transported by a person using manual force to move the system to a desired location.

The portable MRI system 200 includes a slider 260, the slider 260 providing electromagnetic shielding to the imaging area of the system. The slider 260 may be transparent or translucent to maintain the patency of the MRI system, thereby aiding patients who may experience claustrophobia during conventional MRI in a closed bore. The slide 260 may also be perforated to allow airflow to increase openness and/or dissipate noise generated by the MRI system during operation. The slider may have a shield 265 incorporated therein to block electromagnetic noise from reaching the imaging area. According to some embodiments, the slider 260 may also be formed from a conductive mesh that provides shielding 265 to the imaging area and promotes the openness of the system. Thus, the slider 260 may provide a movable electromagnetic shield that allows the patient to be positioned within the system, allows personnel to make adjustments once the patient is positioned or during the acquisition, and/or allows the surgeon to access the patient, etc. Thus, the movable shield facilitates flexibility that allows the portable MRI system to be used not only in unshielded rooms, but also to perform procedures that would otherwise be unavailable. Exemplary sliders that provide different levels of electromagnetic shielding are discussed in further detail below.

According to some embodiments, the portable MRI system does not include a slider, provides a substantially open imaging region, facilitates easier patient placement within the system, reduces the feeling of claustrophobia, and/or improves access to a patient located within the MRI system (e.g., allows a physician or surgeon to access the patient before, during, or after an imaging procedure without having to remove the patient from the system). As an example, fig. 3 shows an exemplary portable low-field magnetic resonance imaging system that can be moved and operated with point-of-care. MRI system 300 may include B similarly to one or more portable MRI systems described in the' 434 patent₀Magnet 322, B₀The magnets 322 include at least one first magnet 322a and at least one second magnet 322b, the first and second magnets 322a and 322b being magnetically coupled to each other by a ferromagnetic yoke 320, the ferromagnetic yoke 320 being configured to capture and direct magnetic flux to increase magnetic flux density within an imaging region (field of view) of the MRI system. The magnets 322a and 322b may be constructed using any suitable technique, including any of the techniques described in the' 434 patent. For example, B₀The magnet 322 may include one or more permanent magnets, one or more electromagnets, printed magnets, or any of the above. MRI system 300 also includes gradient coils 328a and 328b to provide coils for the X, Y, and Z gradients of spatial encoding of MR signals.

B₀Magnet 322 may be coupled to base 350 or attached or mounted to base 350 to support B₀A magnet. Base 350 includes a housing 302, housing 302 being configured to house the electronics necessary to operate portable MRI system 300 (e.g., as detailed in the' 434 patent). To facilitate transport of the system to a point of care, MRI system 300 may include a delivery mechanism. In fig. 3, wheels or casters 382 allow the MRI system to be pushed to a desired position.According to some embodiments, MRI system 300 includes motorized assist devices for facilitating motorized manipulation of the system, some examples of which are illustrated in the' 434 patent. For example, the transport mechanism may include motors that drive wheels/casters 382 to provide motorized assistance in transporting MRI system 300 to a desired location. According to some embodiments, the transport mechanism may include a motorized assist device controlled using a controller (e.g., a joystick or other controller that may be manipulated by a person) to guide the portable MRI system during transport to a desired location. According to some embodiments, the transport mechanism includes a power assist component configured to detect when a force is applied to the MRI system by an operator, and in response, the power assist component engages with the transport mechanism to provide motorized assistance in the direction of the detected force, examples of which are described in greater detail in the' 434 patent.

As shown, MRI system 300 may have a maximum horizontal width W that facilitates maneuverability of the system within a facility in which the MRI system is used. According to some embodiments, the maximum horizontal dimension of the portable MRI system is in the range between 40 and 60 inches, and more preferably in the range between 35 and 45 inches. For example, exemplary MRI system 300 has a maximum horizontal width of approximately 40 inches. As a result, MRI system 300 may be brought to a location where MRI is desired, including to the bedside of the patient to be imaged. MRI system 300 also includes a bridge 373 that mounts to the MRI system to facilitate positioning of the patient within an imaging region of the MRI system. The bridge 373 may be configured to attach to different locations around the base to allow the patient to be positioned within the imaging region from different directions and/or orientations. According to some embodiments, bridge 373 may be around B₀The periphery of the magnet is attached to MRI system 300 in a manner that moves. According to some embodiments, the bridge 373 is configured to be removed and reattached around B₀At different positions of the periphery of the magnet. According to some embodiments, the bridge may be configured to attach to yoke 320, base 350, or any other suitable portion of MRI system 300, as the aspects are not limited in this respect.

The exemplary low-field MRI systems discussed above and discussed in the' 434 patent may be used to provide point-of-care MRI by directly bringing the MRI system to the patient or bringing the patient to a relatively close MRI system (e.g., by pushing the patient to the MRI system in a standard hospital bed, wheelchair, etc.). To facilitate imaging of a patient using the exemplary systems discussed herein, the inventors have developed techniques that allow a patient to be positioned such that the target anatomy is properly located within the imaging region of the MRI system, including techniques that allow the patient to be in position from a standard hospital bed, wheelchair, or other patient support even when the patient has limited or no mobility (e.g., the patient is unconscious, sedated, or anesthetized, or has limited autonomous activity).

The following is a more detailed description of various concepts and embodiments thereof related to point-of-care MRI that allows the use of portable low-field MRI. It should be understood that the embodiments described herein may be implemented in any of a variety of ways. The following provides examples of specific embodiments for illustrative purposes only. It should be understood that the provided embodiments and features/functions may be used alone, together, or in any combination of two or more, as the aspects of the techniques described herein are not limited in this respect.

Figure 4A illustrates a patient handling device that facilitates MRI of a patient from a standard hospital bed. Figure 4A illustrates a first step in positioning the target anatomy of patient 499 within the imaging zone 415 of MRI system 400 (subsequent steps are shown in figures 4B-4I discussed in further detail below). In particular, patient 499 desiring MRI may be confined to bed 490 for convenience, comfort or stability and/or because the patient is unconscious, immobile or unable to move or move safely. Bed 490 may be a standard medical or hospital bed of the type commonly used in emergency rooms, operating rooms, intensive care units, and the like. Such standard hospital beds are typically constructed using ferromagnetic (typically steel) which makes them unusable with conventional clinical MRI systems. In addition, hospital beds often have motorized components for raising and lowering various portions of the bed, which often also contain materials that are not allowed to be placed in the vicinity of a conventional clinical MRI system.

As used herein, the term standard hospital bed or hospital bed generally refers to a bed that is not manufactured to be MRI safe according to existing high-field MRI regulations and/or is not custom used (e.g., manufactured to not contain any ferromagnetic materials) for conventional high-field clinical MRI systems. Thus, standard medical or hospital beds include not only general purpose hospital beds, but beds configured for specific medical purposes, rather than custom beds manufactured to comply with current regulatory requirements for use with conventional high-field MRI. Thus, even if customized for a particular purpose, beds constructed of ferrous or ferrite materials (e.g., ferromagnetic materials such as iron, steel, etc.) or other materials that are prohibited from use in confined areas of conventional clinical MRI are considered standard hospital beds.

For conventional clinical MRI, an exemplary couch 490 may include a steel frame 495, such that, in addition to requiring transport to a dedicated MRI facility, the patient may need to be transferred to an integrated couch of the MRI system and/or to an MRI safe couch (e.g., a couch specially made using aluminum or other non-magnetic material), or both. Such requirements limit the situations in which a patient may undergo MRI, and in some cases prohibit the use of MRI altogether. In fig. 4, the low-field MRI system 400 has been transported to the bedside of the patient for point-of-care MRI. Alternatively, low-field MRI system 400 may be a local facility deployed in an emergency room, operating room, intensive care unit, doctor's office, etc., and bed 490 may be pushed to the MRI system (i.e., MRI system 400 need not be portable). Due to the low field strength of the MRI system 400, the couch 490 may be safely brought close to the B of the MRI system 400₀A magnet 422. Furthermore, the low-field MRI technique is more robust to perturbations that may be caused by ferromagnetic materials in the environment of the couch or the MRI system, allowing the MRI system 400 to operate proximate to the couch 490 and to other devices that may contain ferromagnetic materials in the vicinity.

In the embodiment shown in FIG. 4A, a patient handling device 440 is provided to assist in moving a patient 499 to a position within the imaging region 435 of the MRI system 400. The imaging area or field of view being defined by B₀Magnet (e.g., shown in FIG. 4A as including an upper portionB₀Magnet 422a, lower part B₀Magnet 422B and B of yoke 420₀Magnet 422) produced B₀The magnetic field is suitable for the volume being imaged. More particularly, the imaging area or field of view corresponds to B₀The magnetic field is a region of sufficient homogeneity at a desired field strength that enables detection of MR signals emitted by an object located in the region in response to application of radio frequency excitation (e.g., a suitable radio frequency pulse sequence). In the exemplary MRI system 400, B₀The magnet 422 includes an upper portion B₀Magnet 422a and lower part B₀Magnet 422B, Upper B₀Magnet 422a and lower part B₀The magnets 422B respectively generate pairs B₀B produced by magnet 422₀The magnetic field is the contributing magnetic field. Upper part B₀Magnet 422a and lower part B₀The magnet 422b is configured in a bi-planar configuration to form an imaging region 435 between the two planes. B is₀The magnet 422 further includes a yoke 420 to receive the magnetic flux from the upper part B₀Magnet 422a and lower part B₀The magnetic flux of the magnet 422b is guided to the imaging region 415, thereby increasing the magnetic flux density in the imaging region.

The patient handling device 440 includes a support portion 442 configured to support at least a portion of a patient when the patient is positioned for imaging and a fixation portion 445 configured to releasably secure the patient handling device to a radio frequency coil device (e.g., a radio frequency helmet) and to releasably secure the patient handling device to the MRI system 400, some embodiments of which will be described in further detail below. The securing portion 445 includes at least one releasable securing mechanism configured to secure the patient handling device to a member 429 attached to the MRI system. In the embodiment shown in FIG. 4A, the member 429 is such that the patient handling device is located B when the patient handling device 440 is secured to the member 429₀Upper part B of the magnet₀Magnet 422a and lower part B₀Attached to B at a position between magnets 422B₀Lower part B of magnet 422₀A magnet 422 b. When the member with which the securing mechanism is configured to engage is described as attached to B₀Magnet 422B, meaning that the member is attached to B₀Cover or housing of magnet, any of which is contained in B₀Covers or housings for magnetsInner structure and/or attachment to B₀The magnet itself.

As discussed in further detail below, the securing portion 445 may also include at least one releasable securing mechanism to secure the patient treatment device 440 to the radio frequency coil device such that when the patient treatment device 440 is secured to the radio frequency coil device and member 429, the radio frequency coil device is at least partially located within the imaging region of the MRI system 400, and more preferably substantially located within the imaging region of the MRI system 400. As a result, when the target anatomy of the patient is located within the radio frequency coil secured to the patient handling device 400 and the patient handling device 400 is secured to the member 429, the target anatomy is located within the imaging region 415 of the MRI system 400 for image acquisition.

As described above, the patient handling device includes a support 442, the support 442 configured to support at least a portion of a patient's body to facilitate positioning the patient within an imaging region of the MRI system. The support 442 may include a fold or hinge 442a that allows the patient handling device to be folded to make it more compact (e.g., during storage and/or transport) and unfolded, e.g., during use. The support 442 may be constructed of a molded plastic such as polyethylene or polypropylene. The folding portion 442a may be a living hinge, a piano hinge (piano hinge), or any other suitable hinge that facilitates folding the support portion 442. It should be appreciated that the support 442 may include multiple folds to increase compactness, or may not include folds at all, as various aspects are not limited in this respect.

As shown in fig. 4A, a bridge 473 can be mounted to the MRI system 400 to facilitate positioning of the patient handling device 400 within the MRI system 400 to secure the fixation portion 445 to the member 429 via at least one releasable fixation mechanism. According to some embodiments, bridge 473 is configured to mount to bed 490 instead of MRI system 400. According to some embodiments, the bridge 472 may be configured to be mountable to either or both of a bed and an MRI system, as aspects are not limited in this respect. The bridge 473 can be made of a material that reduces friction between the patient treatment device 400 and the bridge, such as a smooth plastic, to help slide the patient support 440 over the bridge so that the fixation portion 445 can be fixed to the member 429 via at least one releasable fixation mechanism. Examples of releasable securing mechanisms for securing and releasing the patient treatment device to and from the radio frequency coil device and securing the patient treatment device to the MRI system are described in further detail below, according to some embodiments.

Figure 5A illustrates a fixation portion of a patient treatment device according to some embodiments. The securing portion 545 may be similar or identical to the securing portion 445 of the patient treatment device 440 shown in fig. 4. In fig. 5A, a bottom surface (bottom side) of the fixing portion 545 is shown (i.e., a surface opposite to a surface supporting the patient). That is, when the patient treatment device to which the fixation portion 545 is coupled is positioned for use, the surface 545a will face downward toward the bed floor in a direction toward the floor. In figure 5A, the securing portion 545 engages with a member 429 of the magnetic resonance imaging system and a member 531 of the radio frequency coil apparatus to illustrate a technique for securing the patient handling apparatus to the radio frequency coil apparatus and the magnetic resonance imaging system to facilitate positioning of the patient within the magnetic resonance imaging system, according to some embodiments.

The securing portion 545 includes a first releasable securing mechanism 543, the first releasable securing mechanism 543 configured to engage with the radio frequency coil device to secure the securing portion 545 (and thus the patient handling device) to the radio frequency coil device. In the exemplary embodiment shown in fig. 5A, the first releasable securing mechanism 543 comprises a retaining member 543a and a keyhole slot 543b to be engaged with a member 531 of a radio frequency coil apparatus (e.g., a radio frequency helmet) to secure the patient handling apparatus to the radio frequency coil apparatus. The lock hole slot 543b includes a larger diameter portion 543b ' and a smaller diameter portion 543b ", the larger diameter portion 543b ' and the smaller diameter portion 543 b" being dimensioned such that the member 531 can be inserted into the larger diameter portion 543b ' and slid into the smaller diameter portion 543b "in a first direction along the axis 505c (i.e., in an outward direction of the drawing plane), at the smaller diameter portion 543 b", the small diameter preventing member 531 is separated from the lock hole slot 543b in a second direction along the axis 505c (i.e., in a direction opposite to the direction of inserting the member 531 into the lock hole slot 543 b). The securing portion 545 may include additional keyhole slots 549a and 549b having respective larger and smaller diameter portions (e.g., respective larger diameter portions 549a 'and 549b' and smaller diameter portions 549a "and 549 b"), respectively. Additional keyhole slots may be included to assist in securing the radio frequency coil apparatus to a stationary portion, examples of which are shown in fig. 5B and 5C.

The retaining member 543a is configured to allow the member 531 to move into the smaller diameter portion 543b "(i.e., in a first direction along the axis 505 a) and snap into place to retain the member 531 in the smaller diameter portion 543 b" (i.e., the retaining member 543a prevents the member 531 from moving out of the smaller diameter portion into the larger diameter portion in a second direction along the axis 505 a). Thus, once the member 531 is moved from the larger diameter portion 543b' to the smaller diameter portion 543b ", the smaller diameter portion 543 b" and the holding member 543a fix the radio frequency coil device to the fixing portion 545. To disengage the radio frequency coil device from the fixed portion 545 of the patient handling device, a force may be applied to the holding mechanism 543a such that the holding mechanism 543a moves aside to allow the member 531 to move into the larger diameter portion 543b of the keyhole slot 543b, so that the radio frequency coil device may be lifted from the fixed portion 545. For example, a force applied to the radio frequency coil device in a second direction along the axis 505a slides the holding mechanism 543b, thereby allowing the member 531 to slide into the larger diameter portion of the locking hole.

The process of securing and releasing the patient treatment device to and from the radio frequency helmet is described in further detail below in conjunction with fig. 5B and 5C. In particular, fig. 5B and 5C show the underside of the patient handling device 540 including a support portion 542 and a securing portion 545 when engaged with the radio frequency helmet 530. The radio frequency helmet 530 is configured to receive the head of a patient and includes one or more radio frequency coils configured to transmit magnetic resonance pulse sequences and/or detect MR signals emanating from the patient in response to the transmitted pulse sequences. The radio frequency coil may be any of the radio frequency coils and their geometries described in U.S. application serial No.15/152951 entitled radio frequency coil method and apparatus, filed on 31/5/2016, for example. The radio frequency helmet 530 includes a member 53 configured to engage with the securing mechanism 543 of the securing portion 545 of the patient handling device 540, as well as a member 533a configured to engage with the keyhole slot 549a and a member 533b configured to engage with the keyhole slot 549 b.

In fig. 5B, the members 531, 533a, and 533B have been inserted into the respective keyhole slots 543B, 549a, and 549B, and more particularly, the members 531, 533a, and 533B have been inserted through the respective keyhole slots are sized to allow the respective members to be inserted into the respective larger diameter portions of the respective keyhole slots. By moving the radio frequency coil device 530 in the direction indicated by arrow 505 (or moving the patient handling device in the opposite direction), the members 531, 533a and 533b can be moved from the larger diameter portion to the smaller diameter portion of the respective keyhole slot. For example, the member 531 can move from the larger diameter portion 543B' (see fig. 5C) to the smaller diameter portion 543B "(see fig. 5B) of the lock hole slot 543B. The result of this movement is shown in fig. 5C.

As shown in fig. 5C, the radio frequency helmet 530 has been secured to the patient handling device 540. Since the smaller diameter portion of the keyhole slot is sized smaller than the diameter of the portion of the member inserted through the larger diameter portion of the keyhole slot, the radio frequency helmet 530 cannot be lifted from the fixed portion 545 of the patient handling device 540 without first returning to the larger diameter portion. As also shown in fig. 5c, the holding member 543 snaps into place to prevent movement of the member 531 back into the larger diameter portion 543b' of the locking hole slot 543 b. That is, the retaining member prevents movement of the radio frequency coil device 530 in the direction indicated by arrow 505'. However, the resistance of the holding member 543a may be overcome by providing a sufficiently strong force in the direction of arrow 505' to return the radio frequency coil device 530 to the position shown in fig. 5B so that the radio frequency helmet 530 may be moved or lifted away from the fixture 545, thereby disengaging the radio frequency helmet 530 from the patient treatment device 540. In this manner, the securing mechanism 543 releasably secures the radio frequency helmet 530 to the patient treatment device 540 (e.g., the secured helmet can be released from the releasable securing mechanism 543 by providing sufficient force to overcome the resistance of the retaining member).

Fig. 6A and 6B show cross-sectional views of the radio frequency coil device 630 secured within a keyhole slot of a releasable securing mechanism of a securing portion 645 of a patient treatment device. The radio frequency coil device 630 includes a member 631 configured to engage the keyhole slots of the fixation portion 645. The member 631 includes differently sized portions 631a, 631b, and 631c so that the member 631 can be inserted into the keyhole slot and slid into a fixed position. The foot 631a is sized small enough that it can be inserted into the larger diameter portion of the keyhole slot (not visible in fig. 6A and 6B, but with reference to the larger diameter portion 543B' shown in fig. 5A and 5C, for example), and the foot 631a is sized large enough that the foot 631a cannot be inserted into or removed from the smaller diameter portion 643B "of the keyhole slot (also with reference to the smaller diameter portion 543B" shown in fig. 5A and 5B).

The neck 631b is sized small enough that it can be received by the smaller diameter 643b "of the keyhole slot so that the member 631 can be moved into the smaller diameter 643 b" after the foot 631a is inserted into the larger diameter of the keyhole slot. Body portion 631c is sized large enough such that body portion 631c can neither be received by the smaller diameter portion of the keyhole slot nor the larger diameter portion. The height of the neck 631B (e.g., its dimension in the direction of arrow 605 c) is such that when the body 631c prevents further insertion of the member 631 into the keyhole slot (i.e., further movement in the direction of arrow 605c is prevented by the body 631 c), the foot 631a has been positioned through the larger diameter portion of the keyhole slot so that the member 631 can slide into the smaller diameter portion 643B "to the fixed position shown in fig. 6A and 6B. Because the foot 631a is larger than the smaller diameter 643b ", the member 631 cannot be lifted from the fixed portion 645 in the direction of arrow 605c' without first being converted back into the larger diameter portion of the keyhole slot.

Referring again to fig. 5A, according to some embodiments, the retention member 543a is made of plastic and formed into a flat serpentine geometry. For example, the retaining member 543a may be a flat plastic spring having a fixed end 543a 'and a free end 543a "that is movable to allow the member 531 to slide into the smaller diameter portion 543 b" and return to a position to prevent movement of the member 531 back into the larger diameter portion 543 b'. The free end 543a "may be located in the window 503. The depth of window 503 (i.e., generally corresponding to the thickness of retainer 545 in a direction along axis 505 c) may be relatively small. As a result, the retaining member 543a may also have a relatively small thickness in a direction along axis 505c (i.e., the thickness of the material forming the retaining member, e.g., the thickness of the plastic, may need to be relatively thin). That is, the retaining member 543a may be configured to be flat such that the member does not extend beyond the surface 545a (or the top surface of the securing portion 545 on which the radio frequency device sits when engaged). According to some embodiments, the retaining member comprises a flat plastic spring having a thickness of less than or equal to about 0.5 inches. According to some embodiments, the retaining member comprises a flat plastic spring having a thickness of less than or equal to about 0.25 inches. As such, the retention mechanism may be contained within the thickness of the fixation portion 545.

The fixation portion 545 may further comprise a second releasable fixation mechanism 547 configured to engage with the magnetic resonance imaging system to fix the fixation portion 545 (and thus the patient handling device) to the magnetic resonance imaging system. According to some embodiments, the second releasable securing mechanism 547 comprises a tapered lead-in 547a that allows a member 429 attached to the magnetic resonance imaging system to enter the receiving portion 547e, and comprises a retaining portion 547b that prevents the member 429 from exiting the receiving portion 547 d. The handle 547d allows a user to pull the holding portion 547b to allow the member 549 to leave the receiving portion 547 d. The spring 547c allows the releasable securing mechanism to be actuated by use of the handle 547d or under force of the member 429 pushing against the tapered lead-in 547 a. It should be understood that the underside of the member 429 is shown in fig. 5A to illustrate how the releasable securing mechanism 547 engages the member 429, but that the surface 429' of the member 429 is attached to the magnetic resonance imaging system (e.g., to the lower portion B as shown in fig. 4A)₀Surface of magnet 422 b).

Fig. 5D-5F illustrate operation of the example releasable securing mechanism 547. Fig. 5D shows the releasable securing mechanism 547 in a closed position, in which the spring 547c is in a resting position, and the tapered portion 547a and retaining portion 547b extend into the receiving portion 547 e. The releasable securing mechanism 547 can be opened by applying a force on the handle 547d in the direction shown by arrows 505b and 505b' or by applying a force on the tapered portion 547a in the direction shown by arrow 505a to move the securing mechanism 547 to the open position shown in FIG. 5E. When the releasable securing mechanism 547 is opened, the spring 547c is compressed and the tapered portion 547a and the retaining portion 547b separate to allow the member 439 to enter and/or exit the receiving portion 547 e. When the force applied to open the securing mechanism 547 is removed, the spring 547c returns to its resting position, forcing the tapered portion 547a and the retaining portion 547b toward one another to close the path of the aperture 439 into and out of the receiving portion 547e, thereby returning the releasable securing mechanism 547 to the position shown in FIG. 5D.

A force in the direction shown by arrow 505a may be applied by pushing the tapered portion 547a against the member 429, compressing the spring 547c and opening the securing mechanism to allow the member 429 to enter the receiving portion 547 e. After the member 429 enters the receiving portion 547e, the spring 547c returns to its rest position and the retaining portion 547b closes behind the member 429 to secure the fixed portion 545 of the patient handling device 540 to the magnetic resonance imaging system, as shown in fig. 5F. As shown in fig. 5F, the member 429 may include a smaller diameter portion 429a sized to fit within the receiving portion 547e and a larger diameter portion 429b sized to be larger than the receiving portion 547 e. The securing portion 545 is dimensioned such that at least the portion forming the receiving portion 547e fits under the larger diameter portion 429b such that when the securing portion 545 is engaged with the member 429 as shown in fig. 5F, the larger diameter portion 429b prevents the patient handling device 540 from being lifted from the magnetic resonance imaging system in a state in which the retaining portion 547b retains the member 429 within the receiving portion 547e of the releasable securing mechanism 547. In particular, for the example member 429 shown in fig. 5F, the height of the smaller diameter portion 429a allows those portions of the fixation portion 545 that form the receiving portion 547e to fit under the larger diameter portion 429b to retain the fixation portion 545 to the surface to which the member 429 is attached.

To release the patient handling device from the magnetic resonance imaging system, a user can apply a force to the handle 547d in the direction indicated by arrows 505b and 505b' to open the releasable securing mechanism 547 (e.g., to place the releasable securing mechanism 547 in the open position shown in fig. 5E). With the member 429 with the path out of the receiving portion 547e open, the patient handling device 540 may be disengaged from the magnetic resonance imaging system. According to some embodiments, the handles 547d are configured to operate independently of each other such that both sides need to be pulled to open the securing mechanism 547 d. According to some embodiments, pulling on either handle 547d engages on both sides, so only one handle need be used in order to open the securing mechanism 547.

Referring again to fig. 4A, the member 429 may be attached to the MRI system 400 at a location such that a radio frequency coil device that has been secured to the patient handling device is substantially located within the imaging region of the MRI system when the releasable securing mechanism 547 engages the member 429 (e.g., as shown in fig. 5A and 5F). For example, when the radio frequency helmet 530 is secured to the securing portion 545 of the patient handling device 540 via the releasable securing mechanism 543 and the second releasable securing mechanism 547 is engaged with the member 429, the radio frequency helmet 530 is substantially located within the imaging region of the MRI system (e.g., as shown in fig. 4I). As a result, the target anatomy is within the imaging region 415 of the MRI system 400 when the target anatomy is located within the radio frequency coil device.

Fig. 4A-4I illustrate exemplary steps that allow a patient to be imaged from a standard hospital bed, according to some embodiments. In FIG. 4A, a patient handling device 440 may be positioned on a couch 490 adjacent a patient 499 to begin a process of positioning the patient within the MRI system 400. As shown in fig. 4B, patient 499 may be rolled to the side or partially lifted so that the patient handling equipment may be moved toward the center of bed 490 and/or generally aligned with MRI system 400. The patient 499 may then be rolled back or released such that the patient handling device 440 is positioned between the bed 490 and the patient 499 with at least a portion of the patient 499 supported by the support 442 of the patient handling device 440, as shown in figure 4C. The head of the patient 499 may be positioned generally above the fixation portion 445 of the patient handling device 440, which itself may be positioned adjacent the bridge 473 to aid in positioning the patient 499 within the MRI system 400.

As shown in fig. 4D, the radio frequency helmet 430 can be positioned over the bridge 473 or otherwise positioned to engage with the fixation portion 445 of the patient treatment device 440. Then, as shown in fig. 4E, the radio frequency helmet 430 can be secured to the fixed portion 435 of the patient handling device 440 with the patient's head positioned within the radio frequency helmet 430. For example, the radio frequency helmet 430 may be secured by engaging a releasable securing mechanism of the securing portion 435 with one or more cooperating members of the radio frequency helmet 430, as discussed with reference to fig. 5A-5C and 6A-6B. The patient handling device 440 with the radio frequency helmet 430 secured thereto is ready to be moved over the bridge 473 to engage with the member 429 to secure the patient handling device to the MRI system 400 as shown in fig. 4F.

Fig. 4G shows the patient treatment device 440 when the portal access member 429 of the releasable securing mechanism of the securing portion 445 (e.g., access to the portal of the receiving portion of the releasable securing mechanism). As shown, a radio frequency helmet 430 that receives or holds the head of the patient has entered the imaging region 415 of the MRI system 400. In the stage shown in fig. 4H, the member 429 engages with a tapered lead-in of a releasable securing mechanism (e.g., tapered lead-in 547a of releasable securing mechanism 547 shown in fig. 5A and 5D-5F) such that the releasable securing mechanism opens to allow the member 429 to enter a receptacle of the releasable securing mechanism (e.g., receptacle 547e shown in fig. 5A-5F). Once the member 429 has passed beyond the tapered lead-in into the receptacle, the releasable securing mechanism closes and the retaining portion of the releasable securing mechanism prevents the member 439 from exiting the receptacle, as shown in fig. 4I. In this position, the patient handling device 440 is secured to the MRI system 400 and the radio frequency helmet 430 and the patient's head are properly positioned with respect to the imaging region 415 so that one or more image acquisition processes may be performed.

As shown in fig. 4A-4I, point-of-care MRI can be performed by bringing a portable low-field MRI system (e.g., MRI system 400) to the patient (or an MRI system that pushes the patient onto the patient's bed), so that the patient can be MRI from the patient's bed even in cases where the patient is or is not mobile (e.g., the patient is injured, unconscious, or otherwise mobile). As a result, MRI can be made available in many situations not previously available. As described above, because low-field MRI involves relatively low field strengths, it is possible to MRI patients without the need to transport the patient to an MRI safe bed, allowing the patient to be imaged from any bed in which the patient is located, set up the MRI in emergency rooms, operating rooms, intensive care units, doctor's offices and clinics, and the like.

According to some embodiments, the radio frequency coil device may be configured to be directly secured to the MRI system without first being secured to a patient handling device. Figure 7A illustrates a radio frequency helmet configured to directly engage with an MRI system to secure the radio frequency helmet within an imaging region of the MRI system to position a patient to be imaged, according to some embodiments. In particular, fig. 7A shows the bottom side of the radio frequency helmet 730 equipped with a releasable securing mechanism 735, the releasable securing mechanism 735 configured to engage and clamp a member 729 attached to an MRI system. Because the member 729 is attached to the MRI system at a location such that the radio frequency helmet 730 is positioned within the imaging region of the MRI system when the radio frequency helmet 730 is secured to the member 729, the member 729 can be similar or identical to the member 429. As discussed in further detail below, the member 729 can also include a smaller diameter 729a and a larger diameter 729b configured to cooperate with the releasable securing mechanism 735 to secure the rf helmet 730.

The releasable securing mechanism 735 includes a receptacle sized to receive the member 729 and a retainer 737 configured to prevent movement of the cooperating member 729 once the member has been positioned within the receptacle, as shown in fig. 7A. The exemplary retaining portion 737 includes two arm portions 737a and 737b, which arm portions 737a and 737b form a portion of the receiving portion and are configured to clamp the member 729 when the member 729 is positioned within the receiving portion. According to some embodiments, arms 737a and 737b include protrusions 733a and 733b, respectively, the protrusions 733a and 733b configured to inhibit movement of member 729 after member 729 is inserted into a receptacle of releasable securing mechanism 735. The protrusions 733a and 733b include respective outwardly facing sides 733a 'and 733b' and respective inwardly facing sides 733a "and 733 b" sized to facilitate engagement with the member 729 to secure the radio-frequency helmet 730 to the MRI system. According to some embodiments, the angle of the outward facing sides of the protrusions 733a and 733b and the angle of the inward facing sides of the protrusions are configured such that the force required to allow the member 729 to enter the receiving portion of the securing mechanism 735 is less than the force required to allow the member 729 to exit the receiving portion. For example, the relative angles of the outwardly facing side and the inwardly facing side may be selected such that a relatively small force is required on the outwardly facing side to separate arms 737a and 737b to allow member 729 to enter the receiving portion of releasable securing mechanism 735, and a greater force is required on the inwardly facing side to separate arms 737a and 737b to allow member 729 to be released from the receiving portion of securing mechanism 735. It should be appreciated that the protrusions 733a and 733b may be sized in any manner to achieve the desired force required to engage the member 729 with the securing mechanism 735 and disengage the securing mechanism 735, as the aspects are not limited in this respect. Thus, the radio frequency helmet 730 can be secured to and released from the member 729 by applying a force in the appropriate direction. That is, securing mechanism 735 is releasable because after arms 737a and 737b clamp member 729, the clamping may be released by providing sufficient force to helmet 730 such that member 729 separates arms 737a and 737b and releases the member.

As described above, the view in fig. 7A is of the underside of the radio frequency helmet 730 and the member 729 such that the surface 729' is visible. However, this surface is attached to the MRI system at a location such that when the radio frequency helmet 730 is engaged with the member, the helmet and the patient's target anatomy are located within the imaging region of the MRI system (e.g., as shown in fig. 4A-4I). Fig. 7B shows a top view of the releasable securing mechanism 735 engaged with a member 729 of an MRI system. As shown, arm portions 737a and 737b are fitted under larger diameter portion 729b, and protrusions 733a and 733b clamp smaller diameter portion 729 a. In this manner, the larger diameter portion 729b prevents the rf helmet 730 from lifting from the member 729. That is, the larger diameter portion 729b limits the movement of the rf helmet 730 in the direction indicated by arrow 705 a. In addition, arms 737a and 737b limit the movement of the rf helmet 730 in the directions indicated by arrows 705b and 705c (the securing mechanism 735 limits the movement of the member 727 in the plane of the top surface 729 "of the member 729). As described above, although the resistance to movement of the rf helmet 730 away from the securing mechanism 735 can be overcome by applying sufficient force to the helmet, translational movement of the rf helmet 730 can generally be prevented in all directions without such force. However, the releasable securing mechanism 735 can be configured to allow the radio frequency helmet to rotate about the member 729 (e.g., about an axis along arrow 705 a). By allowing the radio frequency helmet 730 this degree of freedom, the radio frequency coil can be oriented as desired about the center of the MRI system, providing flexibility in the direction in which a patient can be inserted into the MRI system. According to some embodiments, an additional securing mechanism is provided to prevent rotation after a desired orientation is reached, as discussed in more detail in connection with fig. 8A and 8B.

Fig. 8A and 8B illustrate examples of releasable fixation mechanisms that allow the radio frequency coil apparatus to rotate about a fixation member of an MRI system to provide the flexibility described above, and include additional fixation mechanisms that hold the radio frequency coil apparatus in place once a desired orientation is achieved, according to some embodiments. Fig. 8A illustrates a cross-sectional view of a radio frequency helmet 830, the radio frequency helmet 830 comprising a releasable securing mechanism 835, the releasable securing mechanism 835 being configured to engage the member 829 to secure the radio frequency helmet 830 to an MRI system. The releasable securing mechanism 835 may be similar to the releasable securing mechanism 735 shown in fig. 7A and 7B. In particular, the releasable securing mechanism 835 can include arms 837a and 837B (shown in fig. 8B), which arms 837a and 837B are configured to grip the member 829 to prevent translational movement of the radio frequency helmet 830, but allow rotation about the member 829. In addition, a second securing mechanism 831 is provided to hold the rf helmet 830 in a particular orientation about the member 829. For example, the securing mechanism 831 can be a peg, pin, or post configured to cooperate with at least one recess 829c (e.g., slot, notch, or other recess) of the larger diameter portion 829b provided in the member 829. When the rf helmet 830 is engaged with the member 829, the helmet may be rotated until the securing mechanism 831 finds the recess 829c to hold the helmet in a fixed orientation of the recess. In this way, the helmet 830 can be secured to the member 829, rotated quickly and held in place in the respective desired orientation. It will be appreciated that the member 829 may be provided with as many recesses around its circumference as desired to allow the radio frequency helmet to be secured to the MRI system in different respective orientations.

Fig. 9A and 9B illustrate a see-through radio frequency helmet (see-through helmet)930 to assist medical personnel in properly positioning a patient within the helmet 930. According to some embodiments, the helmet 930 comprises an outer shell 930a and a coil support 930b for the transmission and/or reception coil, both made of see-through material. The term see-through refers to a structure or material that is transparent or translucent (e.g., semi-transparent) such that the position of the patient's head can be viewed through the helmet. That is, a see-through material refers to a material that is sufficiently transparent to allow medical personnel to visually assess whether the patient is properly positioned by looking through the helmet. The coil support 930b may be adapted to receive the head of the patient and provide a surface on which to arrange the transmit and/or receive coils. The example coil support 930b provides a surface for one or more transmit coils 990a and receive coils 990 b. It should be understood that any configuration or geometry of transmit and/or receive coils may be used, as is not limited in this respect in various respects.

Although electronics used in the operation of transmit/receive coils 930a and 930b may be located external to the housing, exemplary housing 930a may contain such electronics 970, as is not limited in this respect in various respects. The housing 930a can be attached to a base 950 that includes a releasable securing mechanism 935 according to any one or more of the techniques described herein to releasably secure the helmet 930 to the magnetic resonance imaging system within an imaging region of the system. Fig. 9B shows a radio frequency helmet 930 with a patient 999 within a coil support 930B. Because the outer shell 930a and the coil support 930b are see-through (e.g., made of a transparent or semi-transparent plastic material), the patient's head can be viewed through the helmet 930, thus helping to properly position the patient 999 within the helmet 930. It should be understood that while the exemplary helmet 930 includes an outer shell and a coil support, this is not required. For example, according to some embodiments, a radio frequency helmet may be comprised of a single surface on which the transmit/receive coils are disposed, and this surface may be made of a see-through material to assist medical personnel in properly positioning the patient within the helmet.

As mentioned above, the technique for providing a releasable securing mechanism may also be applied to a radio frequency coil device comprising one or more of the following radio frequency coils: the radio frequency coil is adapted to receive a limb such as a leg or arm or a portion of a limb such as an ankle, foot, wrist, hand. Fig. 10A-10D illustrate aspects of a foot coil adapted to receive a foot and configured to secure the foot coil to an MRI system such that the foot is positioned within an imaging region of the MRI system (e.g., within the imaging region of the aforementioned exemplary low-field MRI system). According to some embodiments, the radio frequency device is adapted to receive a foot and is configured to be secured in a plane having biplanar B₀In the imaging region of the magnet-constructed MRI system, in the biplane B₀In the magnet structure, upper and lower portions B₀The space between the magnets may be limited, and some examples of radio frequency devices are described in further detail below.

Fig. 10A shows a view of a radio frequency device 1030 (generally referred to herein as a "foot coil"), the radio frequency device 1030 being adapted to receive a foot for one or more MRI procedures. The foot coil 1030 includes a transmit/receive housing or support 1030t/r on which or within which transmit and/or receive coils for radio frequency equipment are disposed. According to some embodiments, the foot coil 1030 includes a transmit housing for a transmit coil and a receive housing for a receive coil, examples of which are shown in fig. 10B and 10C, respectively, discussed in further detail below. According to some embodiments, the transmit coil and the receive coil may be disposed on or within the same housing (e.g., the transmit coil and the receive coil may be disposed on the same side of a common housing, the outside and inside of the same housing and/or one or more coils may be used for both transmitting and receiving), as not limited in this respect in various respects.

The exemplary foot coil 1030 further includes an outer housing 1030a to at least partially cover one or more transmit/receive housings 1030t/r and form a volume 1030c adapted to receive a foot. As shown in FIG. 10A, volume 1030c has a coil that allows insertion of a foot into the foot coil1030, and height h and w of the interior. In the embodiment shown in fig. 10A, foot coil 1030 is configured at an angle θ relative to a vertical axis. The inventors have recognized that angling the foot coils relative to the vertical axis (e.g., generally pointing away from the vertical axis towards the toes) may provide a number of advantages over vertical orientations. For example, a foot coil set at an angle relative to vertical (i.e., a foot axis greater than zero degrees) helps accommodate a larger foot within the imaging region of the MRI system. In particular, the upper and lower portions B of the aforementioned biplanar configuration₀The distance between the magnets limits the height h of the foot coil (e.g., distance D, labeled in fig. 4G, limits the height of the foot coil that the MRI system can accommodate). As shown in fig. 10A, the axis 1039 is inclined at an angle θ from the vertical. Axis 1039, referred to herein as the foot axis, is the major axis of the foot coil aligned with the foot when the foot is inserted into volume 1030c and angle θ defines the angle at which the foot axis deviates from vertical axis 1025 in the direction of longitudinal axis 1041. That is, the foot axis refers to an axis aligned in a direction from the bottom of the foot coil, where the heel is located, toward the toes when the foot is positioned within the foot coil. In this regard, a foot axis that is at zero degrees (i.e., θ ═ 0 °) to vertical axis 1025 in the direction of longitudinal axis 1041 is aligned with the vertical axis, and in this regard, a foot axis that is at 90 degrees (i.e., θ ═ 90 °) to vertical axis 1025 in the direction of longitudinal axis 1041 is aligned with the longitudinal axis. Exemplary foot coil 1030 has a foot axis 1039 that is approximately 45 degrees from the vertical axis in the direction of the longitudinal axis.

By angling the foot coils (i.e., tilting the foot axis away from the vertical axis), a longer foot may be accommodated within an imaging region of an exemplary MRI system such as described herein (e.g., an MRI system having a biplane configuration as shown in fig. 2-4). That is, the foot coil can accommodate a foot length that is greater than the height of the foot coil in the vertical direction (i.e., L > h as shown in fig. 10A). The greater the angle foot coil 1030 is with respect to the vertical axis, the longer the foot can be accommodated within the same vertical height (i.e., the greater the length L with respect to the height h). Since a person's foot tends to rest with the toes pointing away from the vertical axis (i.e., not with the toes directly above the heel), a foot coil that generally mimics the natural rest of the foot may improve patient comfort during the imaging process. In particular, the angled or inclined foot coil may eliminate the need for the patient to orient the foot to remain straight up and down, which may cause discomfort or pain, particularly in the event that the foot is injured due to disease, infection, or trauma. While large angles (e.g., angles between 60 and 75 degrees) may affect patient comfort in some cases, such angles may be used to construct foot coils that can accommodate a longer foot.

To accommodate larger feet, the foot coils may additionally be tilted away from the vertical axis in a direction toward the lateral axis. That is, in the direction of the lateral axis 1043 shown in FIG. 10A, the foot axis may be inclined at an angle away from the vertical axis 1025Different tilt angles (i.e., tilt angles θ and) May be used alone or in combination to accommodate a variety of foot sizes. In this regard, a foot axis that is zero degrees from the vertical axis 1025 in the direction of the lateral axis 1043 (i.e.,) Aligned with the vertical axis, and, in this regard, at 90 degrees to the vertical axis 1025 in the direction of the lateral axis 1043 (i.e.,) Is aligned with the lateral axis.

It should be appreciated that the foot axis may be selected as desired to suit the imaging application and/or patient requirements, and that multiple foot coils may be manufactured with different foot axes and sizes to facilitate MRI of multiple feet under different conditions and conditions. According to some embodiments, the foot coil is inclined towards the longitudinal axis by an angle between 5 and 60 degrees (i.e. the angle of the foot axis) with respect to the verticalThe degree θ is between 5 and 60 degrees), more preferably at an angle between 15 and 50 degrees, and more preferably at an angle between 30 and 45 degrees (e.g., as shown by foot axis 1039 of exemplary foot coil 1030 shown in fig. 10A). According to some embodiments, the foot coil is inclined towards the lateral axis by an angle between 5 and 60 degrees with respect to the vertical (i.e. the angle of the foot axis)Between 5 and 60 degrees), more preferably at an angle of between 15 and 50 degrees, and more preferably at an angle of between 30 and 45 degrees, or at an angle of about zero degrees as shown in fig. 10A. It should be understood that the leg coils may be canted to have a theta component,A component, or both. As noted above, it should be understood that different foot coils may be configured at different angles to accommodate a variety of feet under a variety of different conditions and circumstances, and that the exemplary foot axes and dimensions described herein are not limiting.

The foot coil 1030 also includes a rear portion 1030b, and when coupled to the bottom portion 1030 b', the rear portion 1030b houses electronics for the foot coil. For example, electronics (e.g., transmit/receive circuitry) forming part of a radio frequency signal chain for operating the transmit and receive coils may be housed in the rear portions 1030b, 1030 b', as discussed in further detail below. The bottom portion 1030 b' also includes terminal connections for a cable harness 1076 that carries power, control, and/or data (e.g., MR signal data) from the MRI system to transmit/receive circuitry housed in the rear portion. In the embodiment shown in fig. 10A, the interface to the MRI system includes a plate 1072 for providing power, control and/or data between the radio frequency device and the MRI system and an adapter 1074 configured to prevent the plate 1072 from connecting to the MRI system in an incorrect orientation. In this manner, the foot coil 1030 may be easily and simply connected to, operated by, and disconnected from the MRI system. The foot coil 1030 also includes a base 1050 coupled to a releasable mechanism that allows the foot coil to be engaged and disengaged with the MRI system. For example, as explained in more detail in connection with fig. 10C and 10D, the base 1050 may be affixed or otherwise coupled to a releasable mechanism that engages a cooperating member located within an imaging region of the MRI system.

Fig. 10B illustrates another view of the foot coil 1030, showing an exemplary nested structure of the foot coil. In particular, fig. 10B shows the receiving housing 1030r and the transmitting housing 1030t prior to insertion into the outer housing 1030 a. In the exemplary foot coil shown in fig. 10B, receive coil housing 1030r (which supports receive coils 1090B, 1090B' described below) is configured to provide an innermost housing adapted to accommodate a volume 1030c of the foot. The transmitting housing 1030t is adapted to fit over the receiving housing 1030r, and the nested transmitting/receiving housing 1030t/r is configured to be inserted into the outer housing 1030 a. However, it should be understood that the order of nesting may be varied and/or a single housing may be provided to support or carry both the transmit and receive coils, as discussed in further detail below.

As can be seen in the view shown in fig. 10B, one or more transmit coils 1090a are disposed on the transmit enclosure 1030t and, more particularly, on an exterior surface of the transmit enclosure. Alternatively or additionally, one or more transmit coils 1090a may be disposed on an interior surface of transmit enclosure 1030t, disposed in a recess or contour fabricated into the enclosure, or integrated into transmit enclosure 1030 t. The one or more transmit coils 1090a can include one or more conductors configured in a three-dimensional geometry about the volume 1030c to generate radio frequency pulses configured to cause MR signals to be transmitted from a patient's foot positioned within the volume 1030c when the foot coil 1030 is engaged with and operated by the MRI system. According to some embodiments, transmit coil 1090a comprises a single conductor disposed in a plurality of turns around the transmit housing 1030t on one or more surfaces thereof. Alternatively, transmit coil 1090a may include a plurality of separate conductors disposed on one or more surfaces of transmit housing 1030 t.

In the embodiment shown in fig. 10A-10D, the one or more transmit coils 1090A operate only as transmit coils, and the receive coils are provided as a separate array of receive coils, as discussed in further detail in connection with fig. 10C. However, according to some embodiments, the one or more radio frequency coils 1090a can also operate as one or more receive coils configured to detect MR signals emanating from the imaged foot in response to a selected pulse sequence generated at least in part by the same coil operating in a transmit mode. In such embodiments, the one or more radio frequency coils 1090a operate as a transmit coil and a receive coil. The geometry (e.g., relative spacing of turns, geometry of contours, etc.) of the one or more transmit coils 1090a may be determined to substantially optimize the characteristics of the transmitted radio frequency pulses based on the geometry of the volume 1030c using any of the techniques described in, for example, U.S. patent publication No.2016/0334479 entitled "radio frequency coil method and apparatus" published on day 17/11/2016. For example, the magnetic model may be used to determine the geometry of the one or more transmit coils 1090a that generally optimizes the magnetic pulses delivered to the volume 1030 c.

As described above, the receiving housing 1030r may be configured to fit within the transmitting housing 1030 t. As can be seen in the view shown in fig. 10B, a plurality of receive coils 1090B and 1090B 'configured to detect magnetic resonance signals emitted from the patient's feet in response to radio frequency pulses emitted by a transmit coil (e.g., one or more transmit coils 1090a) are disposed on the receive housing 1030 r. As with the transmit coils, the receive coils may alternatively or additionally be disposed on an inner surface of the receive housing 1030r, or otherwise integrated within the housing. In the embodiment shown in fig. 10B and 10C, the receive coils include eight separate receive coils: six receive coils 1090b (e.g., three overlapping receive coils on each side of the receive enclosure 1030 r) and two receive coils 1090 b' (e.g., receive coils disposed at least partially on the top and bottom of the receive enclosure).

In the exemplary configuration shown in fig. 10B and 10C, the receive coil 1090B is positioned in an overlapping configuration to reduce inductive coupling between the coils. Spatially, the reception coil 1090b is inclined with the same characteristic as the leg coilIn the vertical direction (e.g., B indicated by arrow 1025 as a whole)₀In the direction of the magnetic field). That is, the receive coils may be aligned with the foot axis of the foot coil such that each successive receive coil is offset from an adjacent receive coil in a horizontal direction (e.g., in a longitudinal direction). With this configuration, the receive coil is structured to detect MR signals emitted from the patient's foot along with B generated, for example, by the exemplary MRI system previously described and illustrated₀The magnetic field is emitted in the direction of the orthogonal axis. Receive coil 1090B' is positioned on the top and bottom surfaces of receive housing 1030r for detection along and B generally₀Magnetic resonance imaging signals emitted in the direction of the other axis orthogonal to the magnetic field. In this way, the receive coils may be generally configured as quadrature coils to substantially optimize the detection of the MR signals. It should be appreciated that receive coils 1090b and 1090 b' are merely exemplary, and that any number of coils in any suitable configuration may be used, as is not limited in this respect in numerous respects.

As shown in fig. 10C, the receive enclosure 1030r includes a rear side 1032r, the rear side 1032r having an electronics connection to electronics 1070 on the bottom portion 1030b 'that, when connected, allows power, control and/or data (e.g., MR signal data) to be exchanged between the MRI system and the foot coils (e.g., between the MRI system and the transmit and receive coils 1090a, 1090 b'). In particular, when the adapter 1074 is connected to the MRI system in the manner discussed above in connection with fig. 10A, power, control, and/or data may be exchanged via the connection cable 1076 and the board 1072.

The view in fig. 10C shows a base 1050 supporting the radio frequency coil housing and a releasable securing mechanism 1035, which when assembled, is coupled to the bottom of the base 1050. According to some embodiments, the releasable securing mechanism 1035 includes a retainer 1037 configured to grip a cooperating member that is attached to the MRI system within the imaging region in a manner similar or identical to the securing mechanisms discussed above for the radio frequency helmets described in connection with fig. 7A-7B and 8A-8B. An example of one embodiment of the securing mechanism 1035 is described in further detail in connection with the bottom view of the foot coil 1030 shown in figure 10D.

Fig. 10D illustrates a bottom view of the foot coil 1030 according to some embodiments, showing a securing mechanism 1035 configured to directly engage with an MRI system equipped with cooperating members to secure the foot coil 1030 within an imaging area of the MRI system. In particular, in the embodiment shown in fig. 10D, the outer housing 1030a may be coupled to a base 1050, which in turn may be coupled to a releasable securing mechanism 1035, which releasable securing mechanism 1035 is configured to engage and clamp a cooperating member (e.g., member 729 shown in fig. 7A and 7B) that is attached to the MRI system at a location such that the foot coil 1030 is positioned within an imaging region of the MRI system when the foot coil 1030 is engaged with the cooperating member. In this way, the patient's foot positioned within the foot coil 1030 is properly positioned for imaging when attached to the MRI system.

The exemplary releasable securing mechanism 1035 includes: a circular receiving portion sized to receive a cooperating member attached to the MRI system; and a retaining portion 1037 configured to prevent movement of the cooperating member once it has been positioned within the receiving portion. The exemplary retention portion 1037 includes two arm portions 1037a and 1037b that each form a portion of the receiving portion and are configured to grip the cooperating member when positioned within the receiving portion. According to some embodiments, the arms 1037a and 1037b include protrusions 1033a and 1033b, respectively, configured to resist movement of the cooperating members upon insertion into the receiving portions of the releasable securing mechanism 1035. The protrusions 1033a and 1033b include respective outwardly facing sides 1033a 'and 1033 b' and respective inwardly facing sides 1033a "and 1033 b" sized to facilitate securing of cooperating members of the MRI system to the foot coil 1030.

According to some embodiments, the angle of the outward facing sides of the protrusions 1033a and 1033b and the angle of the inward facing sides of the protrusions are configured such that the force required to allow the cooperating members to enter the receiving portion of the securing mechanism 1035 is less than the force required to allow the cooperating members to exit the receiving portion (e.g., the force required to engage the cooperating members is less than the force required to disengage the cooperating members). For example, as discussed above in connection with the radio frequency helmet 735, the relative angles of the outward-facing and inward-facing sides may be selected such that a relatively small force is required on the outward-facing side to separate the arms 1037a and 1037b to allow the cooperating members to enter the receiving portion of the releasable securing mechanism 1035, and a greater force is required on the inward-facing side to separate the arms 1037a and 1037b to allow the foot coils 1030 to be released from the cooperating members (e.g., to allow the cooperating members to be released from the receiving portion of the securing mechanism 1035).

It should be appreciated that the protrusions 1033a and 1033b may be sized in any manner such that a desired force effects engagement and disengagement of the securing mechanism 1035 with the cooperating member, as the aspects are not limited in this respect. Thus, the foot coil 1030 may be secured to and released from the MRI system by applying a force in the appropriate direction. That is, the securing mechanism 1035 is releasable because, after the arms 1037a and 1037b are engaged with the cooperating members, the foot coil 1030 can be released by applying sufficient force on the foot coil such that the cooperating members force the arms 1037a and 1037b outward and release the foot coil from the cooperating members. According to some embodiments, the cooperating member is similar or identical to the member 829 shown in fig. 8A and 8B, the member 829 includes a recess (e.g., recess 829c) and the securing mechanism 1035 includes a pin or post (e.g., similar or identical to pin 831 shown in fig. 8A and 8B), such that the foot coil may be rotated about the cooperating member until the pin finds the recess and prevents further rotation.

Fig. 11 shows a foot coil suitable for use with a larger foot, such as a swollen foot caused by swelling due to disease (such as diabetes or complications causing edema (e.g., congestive heart failure, renal or liver disease, etc.)), infection, or trauma, or a larger person's foot. The foot coil 1130 may be similar in many respects to the foot coil 1030 shown in FIG. 10A. However, the foot coil 1130 is configured with a width W that is greater than the width W of the coil 1030 shown in fig. 10A to accommodate a larger foot (and more particularly, to accommodate a larger width foot characteristic of disease or edema), thus providing the foot coil 1130 with a larger volume 1130 c. As described above, the angle at which the foot coil is tilted relative to vertical may be selected based on patient comfort to accommodate a larger foot, to accommodate other conditions or imaging conditions, and the like. Similarly, the foot axis of foot coil 1130 shown in FIG. 11 may also be altered for comfort and/or to accommodate a longer foot. Similarly, different foot coils can be manufactured at different angles so that various patient and imaging conditions can be accommodated.

Fig. 12A shows the foot coil 1230 engaged with the cooperating members of the MRI system 1200 in a manner such that the foot coil 1230 and the right foot located therein are within the imaging region of the MRI system 1200 and are properly positioned for imaging. Fig. 12B and 12C show different views of a foot coil 1230 positioned with the MRI system 1200. Fig. 12D shows a foot coil 1230 for receiving the left foot. Additionally, fig. 12D shows a support 1231 (also visible in fig. 12A-12C) inserted within the foot coil 1230 to support the foot and provide comfort to the foot during imaging.

As mentioned above, imaging a patient using MRI from, for example, a standard hospital bed typically requires positioning the patient's target anatomy within an MRI system located near the hospital bed on which the patient is lying. As discussed in connection with fig. 4A-4I, the inventors have developed techniques that facilitate positioning a patient within an MRI system for imaging a desired anatomy of the patient from a patient's bed. For example, fig. 4A illustrates a portable low-field MRI system 400 that has been moved to a position near a standard hospital bed 490 for MRI of a patient 499 who may be confined to the bed for convenience, comfort, or stability and/or because the patient is unconscious, immobile, or otherwise immobile or not safely mobile. The portable MRI system 400 may be a local facility deployed in an emergency room, operating room, intensive care unit, doctor's office, etc., and the portable MRI system may be moved to the bed 490, or in some cases, the bed 490 may be pushed to the MRI system. As discussed in detail above, bed 490 may be safely located near MRI system 400 due to the low field strength of MRI system 400.

To bridge the gap between the couch 490 and the MRI system 100, the MRI system may be equipped with a bridge 473 mounted to the MRI system 100 to facilitate positioning the patient 199 within the imaging region of the MRI system 100. In particular, the bridge 473 provides a surface 474 over which the patient 499 can move so that the anatomy of the patient being imaged (e.g., the patient's head) can be positioned within the imaging region of the MRI system. However, the inventors have recognized that the exemplary bridge 473 shown in fig. 4A can be improved in a variety of ways. For example, the bridge 473 can be designed to work in conjunction with the patient support 440 such that the size of the bridge 473 is sufficient so long as the bridge is of a size that is suitable to allow the patient support to transition over the surface of the bridge. However, in some embodiments, the patient may be positioned within the MRI system 400 without assistance from a patient support. In such embodiments, a larger sized bridge may be preferred to facilitate both easy and comfortable positioning of the patient, as well as accommodate larger and heavier patients. The inventors have developed a bridge adapted to facilitate patient positioning that is generally optimized for use with or without a patient support.

As shown in fig. 4A, the fixed bridge 473 extends from the MRI system, thereby increasing the footprint of the system. As a result, navigating the MRI system through corridors and doorways is more difficult. Furthermore, the available surfaces of the bridge 473 are limited and the configuration of the bridge may not be suitable for heavier patients, particularly if the patient is positioned without the aid of a patient support. As a result, the bridge 473 may be difficult to use with larger and/or heavier patients and may not be rated to support the heaviest patient. However, increasing the size of the bridge to help the patient position and/or support a larger or heavier patient without patient support results in the bridge protruding further from the MRI system and requiring a more robust configuration.

The inventors have recognized the benefits of a patient support bridge that can support larger and heavier patients, and have appreciated the benefits of such a bridge that can accommodate a range of gaps between the MRI system and the patient bed and/or provide more overlap between the bridge and the bed. In particular, it is desirable to equip portable MRI systems with relatively large size bridges that can safely support a variety of patients for the comfort, safety, and/or to facilitate more convenient positioning of the patient, particularly for larger and/or heavier patients. However, there are a number of problems associated with the design and development of relatively large size bridges that can support the weight of larger patients.

For example, as described above, the larger bridge further increases the footprint of the MRI system, making it more difficult (or impossible) to transport the MRI system down a hallway and through the doorway of the health facility in which the system is deployed. To address the problem of increased footprint of the MRI system, the inventors have developed a folding bridge that can fold down to help position the patient within the imaging area of the MRI system and support the patient during imaging, and that can fold up during transport of the MRI system so that the MRI system can more easily move along the hallway and through the doorway to the patient.

Furthermore, providing a bridge that can safely support a large, heavy patient requires a robust construction. Typically, such patient supports will be constructed using a large amount of metallic material capable of withstanding the significant stresses caused by the weight of the supporting heavy patient. However, a large amount of metal may negatively affect the operation of the magnetic resonance imaging system to which the bridge is attached by distorting the main magnetic field and/or generating a large amount of eddy currents during operation of the magnetic resonance imaging system that negatively affects the image quality. To alleviate this problem, some embodiments include upwardly folding the bridge, wherein the metal composition of the bridge is minimized to the extent that a bridge capable of supporting a heavy patient while minimizing the impact on the operation of the magnetic resonance imaging system can be provided. Thus, the exemplary upwardly folding bridges described herein may be able to safely and reliably support large and/or heavy patients, thereby taking full advantage of the larger size bridges without significantly affecting the ability of the MRI system to move along hallways and through doorways.

Following is a more detailed description of various concepts and embodiments thereof related to a folding bridge that can be moved from a vertical position for stowage during transport of a portable low-field MRI system or when the MRI system is not in use to a horizontal position to facilitate positioning of a patient while in point-of-care MRI. It should be appreciated that the embodiments described herein may be implemented in any of a variety of ways. The following provides examples of specific embodiments for illustrative purposes only. It should be understood that the embodiments and features/functions provided may be used alone, together, or in any combination of two or more, as the aspects of the techniques described herein are not limited in this respect or to the specific combinations described.

Fig. 13A and 13B illustrate an exemplary folding bridge for supporting a patient during positioning and imaging according to some embodiments. Bridge 1300 is configured to be placed in a stowed or "collapsed" position (also referred to simply as a "cocked" or "upright" position) or in an operative or "collapsed" position (also referred to simply as a "lowered" or "horizontal" position), respectively. The bridge 1300 includes a support 1310 configured to bridge a gap between an MRI system to which the bridge is attached and, for example, a hospital bed to which the MRI system is proximate. Support 1310 includes a surface 1310a that is designed to support the patient during positioning and imaging when the bridge is placed in the down position shown in fig. 13B.

When bridge 1300 is in the lowered position, surface 1310a of support member 1310 is substantially horizontal to provide support for the patient. Support 1310 (and particularly surface 1310a) may be made of a material that reduces friction between the patient and the bridge, such as a smooth plastic, to help position the patient within the imaging region of the MRI system without creating eddy currents during operation of the system. As shown in fig. 13A, when bridge 1300 is in the erect position, surface 1310a (visible in fig. 13B) of support 1310 is substantially vertical such that the support does not substantially increase, if possible, the size of the magnetic resonance imaging system (e.g., the bridge does not increase the outer perimeter or footprint of the system when the bridge is in the erect position).

Bridge 1300 includes hinges 1350 that allow support 1310 to pivot from the erected position to the lowered position and vice versa (e.g., hinges 1350 allow bridge 1300 to move between the positions shown in fig. 13A and 13B). According to some embodiments, hinge 1350 includes a shaft 1355, which shaft 1355 allows support 1310 to pivot or rotate from the vertical position shown in fig. 13A to the horizontal position shown in fig. 13B, and vice versa. Specifically, the exemplary bridge 1300 includes a base portion 1352 and a pivot portion 1358, with a shaft 1355 passing through the base portion 1352 and the pivot portion 1358 to allow the pivot portion 1358 to pivot when the bridge is folded up and down. The base 1352 is configured to attach to the MRI system and includes a stop 1353 (see fig. 13A) and a stop 1354 (see fig. 13B), the stops 1353 and 1354 providing end stops to prevent the bridge from pivoting further when reaching the horizontal and vertical positions, respectively.

The base 1352 also includes counterbores 1345 (e.g., holes 1345a, 1345b, and 1345c) to accommodate bolts that allow the bridge 1300 to be securely attached to the MRI system. For example, according to some embodiments, the base 1352 is configured with three counterbores to accommodate corresponding M8 bolts, the M8 bolts securely attach the base of the bridge directly to the B of the MRI system₀A magnet (e.g., as shown in fig. 17A-17C discussed below). Bolting the bridge to the MRI system in this manner helps the bridge to withstand the torque due to the weight of the patient.

As described above, the inventors have recognized the benefit of providing a bridge that can accommodate larger (e.g., wider) and heavier patients and can bridge a larger gap between the patient bed and the MRI system and/or provide additional overlap with the patient bed when placed in the lowered position. According to some embodiments, the folding bridge is configured to have a width of between 12 and 36 inches and a length of between 8 and 24 inches. For example, exemplary bridge 1300 has a width W of at least 24 inches and a length L of at least 12 inches to provide a relatively large surface to accommodate a variety of patients and to bridge various gaps. The length of the bridge refers to the dimension generally in the direction outward from the MRI system. By increasing the length of the bridge, a larger gap may be bridged and/or a larger overlap with the patient bed may be achieved.

The width of the bridge means the dimension generally in a direction tangential to the MRI system. By increasing the width of the bridge, wider patients can be more comfortably accommodated and supported. Hospital equipment for emergency care may typically be rated to accommodate a patient weighing 500 pounds (e.g., hospital beds are typically rated to support 500 pounds of patients). According to some embodiments, bridge 1300 is also rated for a 500 pound patient and can be constructed with a safety factor of at least 2.5 (i.e., its yield strength is at least 2.5 times rated). According to some embodiments, bridge 1300 is rated for a 500 pound patient and is constructed with a safety factor of 4.0 or greater, examples of which are described in further detail below.

Fig. 14 illustrates components of a folding bridge 1400 according to some embodiments to illustrate exemplary construction details. Similar to bridge 1300 described above, bridge 1400 includes a support member 1310 having a surface 1310a configured to support a patient during positioning and imaging. The bridge 1400 also includes a hinge 1350, the hinge 1350 including a base portion 1352 and a pivot portion 1358 that allow the support 1310 to pivot from an upright position to a horizontal position (and vice versa) when coupled via a shaft 1355. For the example bridge 1400, a tongue and groove interface may be used to couple the support 1310 to the pivot portion 1358. Specifically, support 1310 includes a groove 1317 configured to receive a tongue 1357 extending from pivot 1358. To couple the support to the pivot, the tongue 1357 may be inserted into the groove 1317 and screwed or bolted into place to secure the support 1310 to the pivot 1358.

To construct the hinge 1350, the pivot portion 1358 includes shoulders 1359a and 1359b with a gap 1363 positioned between the shoulders 1359a and 1359b that is sized to receive the base portion 1352. The shoulders 1359a, 1359b and the stop 1354 of the base 1352 include mating holes 1365 through which the shaft 1355 is inserted to allow the support 1310 to pivot between the raised and lowered positions. In construction, the shaft 1355 is secured within the base and pivot portion holes 1365 with nuts 1366a and bolts 1366b at the ends of the shaft. Pivot portion 1358 is therefore allowed to pivot such that support 1310 can move from an upright position when not in use (i.e., a position in which plane 1310a is substantially vertical) to a horizontal position (i.e.,a substantially horizontal position of the plane 1310a) to facilitate positioning the patient within the imaging region of the MRI system and supporting the patient during imaging. As described above, the bridge 1400 can be bolted to the MRI system via bolt holes 1345a-c (e.g., to the lower portion B of the MRI system)₀A magnet such that the bridge 1400 is flush with the patient surface within the imaging region of the MRI system, as shown in fig. 6A-6C discussed below).

The bridge 1400 may also include ball plungers 1380a and 1380b that help to maintain the bridge in a vertical position when the bridge is not in use. For example, ball or spring plungers 1380a and 1380b may be positioned on either side of the base portion 1352 to interact with the shoulders 1359a and 1359b of the pivot portion 1358. Specifically, to move the bridge 1400 from the vertical position to the horizontal position, the shoulders of the pivot must first overcome the resistance provided by the spring-loaded ball plunger (i.e., to pivot the bridge 1400 out of the vertical position, the shoulders 1359a and 1359b must first move over the ball plunger providing a reaction force for the initial rotation of the pivot). Thus, safety measures are provided by reducing the chance that the bridge 1400 will accidentally fall from the vertical position to the horizontal position, since an initial force exceeding the resistance of the ball plunger is required to move the bridge out of the vertical position. The bridge 1400 may also include a rubber stopper 1393, the rubber stopper 1393 configured to fit within a corresponding hole provided in the stop 1353 of the base portion 1352 to reduce noise generated when the shoulders 1359a, 1359b contact the stop 1353 as the bridge moves to the down position and/or to absorb some impact of the bridge, which should be a fall of the bridge or a rough handling of the bridge during transition to the horizontal position.

Fig. 15A illustrates a model of a folding bridge 1500 configured to support a larger and/or heavier patient according to some embodiments. The model shown in fig. 15A is used to perform multiple performance tests on an exemplary bridge 1500 designed to provide a relatively large surface to aid in patient positioning and configured to support a heavy patient (e.g., up to 500 pounds of nominal). The following dimensional, material, and construction details are provided merely as illustrations of exemplary bridge 1500 for stress testing, and are not limiting in this respect to folding the bridge. In particular, different sizes, materials, and designs may be used to construct the folding bridge, and the different aspects of the folding bridge discussed herein may be used in different combinations. Bridge 1500 illustrates just one example of a suitable folding bridge that can support larger and/or heavier patients and provide a relatively large surface to facilitate patient positioning and support.

Bridge 1500 is provided with a support 1310 having a relatively large surface area, for example, 24 inches in width and 14.4 inches in length measured from the distal end of support 1310 to the center of the curved interface where bridge 1500 is bolted to base 1352 of the MRI system (i.e., at counterbore 1345 b). Support 1310 is formed at least in part from a 1 inch thick plastic platform that provides a surface 1310a over which a patient can move to position the patient within the MRI system. Similar to the configuration of the exemplary bridge 1400, the pivot 1358 is coupled to the support 1310 via a tongue and groove interface and to the base via a 16mm diameter shaft 1355 that is inserted through the shoulders 1359a and 1359 b. For the exemplary bridge 1500, the shoulders 1359a and 1359b are constructed of metal (e.g., aluminum), while the tongue 1357 is constructed of plastic (or other non-metallic material). The base 1352 of the exemplary bridge 1550 is constructed of a metal, such as steel, and includes a B for bolting the bridge 1500 to the MRI system₀Three counterbores 1345a-c for magnets (e.g., using three corresponding M8 bolts). As such, the components of the bridge 1500 that experience the greatest amount of stress may be constructed of metal, and the components that experience less stress may be made of plastic (or other non-metallic materials) to minimize eddy current generation when operating the MRI system, while providing a robust construction for the bridge.

To evaluate the performance of the exemplary bridge 1500, a stress test was simulated on a model of the bridge 1500 to ensure that the design reached a nominal value of 500 pounds with a safety factor appropriate for patient support equipment. In particular, using the above-described construction details, a mesh was applied to the model of the bridge 1500 as shown in fig. 15A and the stress induced by the patient's body weight was simulated via finite element analysis. The weight required for bridge 1500 to support a 500 pound patient is available from International Electrotechnical Commission (IEC)60601-1 international standard. Specifically, IEC 60601-1 establishes a number of safety requirements and performance standards for medical equipment.

Fig. a.19 of IEC 60601-1 (which is reproduced here as fig. 15D) shows an example of a human mass distribution for determining how a 500 pound patient's weight is distributed over the patient support surface of the exemplary bridge described herein. As shown in FIG. 15D, panel A.19 of IEC 60601-1 specifies the length dimension (in millimeters) and the percentage of the patient's body mass that is important to the human body when supine. Specifically, the head accounts for 7.4% of the patient's mass, the trunk accounts for 40.7%, the upper arms account for 7.4% in total, the lower arms account for another 7.4% in total, the thighs account for 22.2%, and the calves account for 14.8%. When the patient is positioned within the portable MRI system, the head is located within the imaging region and supported by the MRI system (e.g., by a helmet on which the transmit/receive coils are located), such that the bridge needs to support at least some portions of the torso, shoulders, and arms of the body. The total contribution of the torso and upper arms was about 50% (48.1%) of the patient's body weight. Thus, in an approximate number, for a bridge rated at 500 pounds with a safety factor of 1, the bridge would need to support 250 pounds (i.e., 50% of the patient's total weight). If the safety factor is 2.5, the bridge needs to support 625 pounds (i.e., 50% of the patient's weight multiplied by 2.5), and if the safety factor is 4, the bridge needs to support 1000 pounds (i.e., 50% of the patient's weight multiplied by 4).

To evaluate a 500 pound rated bridge 1500, the stress on the bridge 1500 caused by a 500 pound patient (i.e., 50% of the patient's weight that the bridge needs to support) is simulated by distributing 250 pounds of weight over the surface of the bridge, as shown by the downward arrow in fig. 15A-15C. Using the materials and dimensions discussed above, this distributed weight results in the stress diagram shown in fig. 15B. The maximum stress generated at the base corners shown by arrows 1553a and 1553b is 6981 psi. The yield strength of the exemplary bridge 1500 was also evaluated to evaluate the maximum stress that the bridge 1500 can withstand. The yield strength of the bridge 1500 is determined to be 30000 psi. Thus, exemplary bridge 1500 achieves a rating of 500 pounds with a safety factor of 4.3. Specifically, the yield strength of the bridge is 4.3 times greater than the maximum stress produced by simulating a 500 pound patient's force on the bridge 1500.

Fig. 15C shows a deflection plot showing bridge deformation at a simulated weight of 250 pounds. The maximum deflection of the bridge produced by the simulation was 1.5mm at the distal end of support 1310. In particular, the arrows show the position of the bridge without the application of a simulated force. In fig. 15B and 15C, the displacement resulting from applying 250 pounds is shown at a scale of 36.4 to magnify the displacement so that it can be visualized (i.e., the actual displacement is 36.4 times less than the displacement that occurs in the graphs shown in fig. 15B and 15C). Thus, a 250 pound weight distributed over bridge 1500 to simulate the stress generated by a 500 pound patient results in a maximum displacement of 1.5mm at end 1310b of support 1310.

The inventors have recognized that some embodiments of the folding bridge may be relatively large and heavy, particularly when sized and configured to help position and support large, heavy patients. For example, an exemplary bridge may be sized to have a length of between 1 and 2 feet or more and a width of between 1.5 and 2.5 feet or more, resulting in a bridge that may weigh between 8 and 15 pounds or more. Larger, heavier bridges can cause injury if the bridge is accidentally dropped from a vertical position. To prevent the bridge from being able to fall freely, the inventors have developed a counterbalance mechanism configured to slow the rate at which the bridge can transition from the erect position to the down position. The counterbalance mechanism provides an additional safety precaution that can protect the patient and the healthcare worker from possible injury, as discussed in further detail below.

Fig. 16A and 16B illustrate components for a bridge 1600 according to some embodiments. Exemplary folding bridge 1600 can include many of the same components described in connection with bridge 1400 shown in fig. 14 and/or bridge 1500 shown in fig. 15A-15C. However, the bridge 1600 includes a counterbalance mechanism configured to slow the rate at which the folding bridge 1600 can pivot to the horizontal position. According to some embodiments, the balancing mechanism includes torsion springs 1375a and 1375 b. Torsion springs 1375a and 1375b are configured to fit over respective ends of shaft 1655. Each torsion spring 1375a, 1375B is configured with an end 1376a and 1376B, the ends 1376a and 1376B protruding from the spring in the direction of the longitudinal axis of the shaft, as can best be seen in the enlarged portion of one end of the balance member shown in fig. 16B.

In particular, end portions 1376a are disposed in the axial direction of shaft 1655 on the periphery of the respective torsion springs and are configured to fit into respective indexing holes 1378 provided in indexing members 1377a, 1377 b. End 1376b is similarly configured and constructed to fit into corresponding indexing holes 1378 provided in shoulders 1659a and 1659b of pivot portion 1658. Specifically, indexing members 1377a, 1377B include a plurality of indexing holes 1378 (e.g., with reference to exemplary indexing holes 1378a and 1378B shown in fig. 16B) around a perimeter to receive end 1376 a. Shoulders 1659a and 1659b include notches 1656a and 1656b to receive respective torsion springs. Notches 1656a and 1656b include holes 1365 through which shaft 1655 passes, and also include indexing holes 1378 into which end 1376b is inserted (as best seen by indexing holes 1378d disposed in notch 1656b next to holes 1365). For example, end 1376b of each torsion spring 1375a, 1375b fits into a respective indexing hole 1378c and 1378d such that one end of the torsion spring is coupled to the indexing member 1377 and the other end is coupled to the pivoting member 1658.

Shaft 1655 includes flats 1655a and 1655b configured to fit into respective indexing members 1377a and 1377 b. Specifically, flattened portions 1655a and 1655B are configured to be inserted into slots 1379 (as best seen in the enlarged view shown in fig. 16B) provided in respective indexing members 1377a, 1377B and secured by bolts 1666a and 1666B at opposite ends of shaft 1655. To assist in operating the counterbalance mechanism, respective bolt holes 1336a and 1336b are provided through the stop 1354 of the base 1352 and into the shaft 1655, respectively, to receive bolts 1335 to hold the shaft 1355 in place. Specifically, bolts 1335 are inserted through bolt holes 1336a in the base and into bolt holes 1336b in the shaft 1655 to prevent rotation of the shaft as the pivot portion 1658 rotates during the transition between the raised and lowered positions. Preventing rotation of the shaft 1355 ensures that rotation of the pivot portion 1658 will cause the torsion springs 1375a, 1375b to tighten or tighten, thereby slowing the rate at which the pivot portion 1658 can rotate, as discussed in further detail below. When the bridge is assembled, sleeves 1360a and 1360b cover respective torsion springs 1375a and 1375 b.

When configured as described above, shaft 1655 is fixed in place and prevented from rotating by inserting shaft 1655 through hole 1365 and into slots 1379 of respective indexing portions 1377a, 1377b and screwing shaft 1665 into place via screws 1666a, 1666b, and 1335. By inserting end portions 1376a and 1376b of torsion springs 1375a, 1375b into indexing portions 1377a, 1377b and pivot portion 1658, respectively, rotation of pivot portion 1658 from the vertical position to the horizontal position causes torsion springs to tighten due to the fixed connection (not rotating) between end portion 1376a and indexing members 1377a, 1377b and between end portion 1376b and indexing holes 1378c, 1378d in notches 1656a, 1656b, respectively (causing end portion 1376b to rotate with pivot portion 1658). That is, because indexing holes 1378c and 1378d and end 1376b are aligned in the direction of the shaft axis but positioned off-axis, as indexing holes 1378c and 1378d rotate about the shaft axis, rotation of the pivot causes the torsion spring to tighten. Thus, when the bridge pivots from the vertical position to the horizontal position, the torsion of the torsion spring slows the rotation of the support 1310, thereby preventing the bridge from rotating freely in a fall. The spring constant of the torsion spring may be selected to achieve a desired level of control of the rate at which the bridge is allowed to transition between the raised and lowered positions. In this way, the bridge 1600 includes a counterbalance mechanism that provides an additional safety mechanism to reduce the chance of injury when using a folding bridge.

As described above, the example folding bridges described herein are configured to attach to a portable magnetic resonance imaging system to help position and support a patient during point-of-care MRI. Fig. 17A, 17B, and 17C illustrate a portable low-field MRI system to which an exemplary folding bridge described herein may be attached. In particular, portable low-field MRI system 10000 can be deployed in almost any environment to image patients, for example, from standard hospital beds located in emergency rooms, intensive care rooms, operating rooms, newborn rooms, clinics, primary care rooms, recovery rooms, etc., where conventional MRI is not typically available. Because it can be stowed in a vertical position during transport or when not in use and folded down when needed for, for example, point-of-care MRI, the exemplary folding bridge can be configured to facilitate the positioning and support of large and heavy patients without significantly increasing the footprint of the MRI system.

In particular, to facilitate shipping portable MRI system 10000 to a location where MRI is desired, portable MRI system 10000 is equipped with a folding bridge 1700, which folding bridge 1700 can include any one or more features of the folding bridge described herein. Fig. 17A shows bridge 1700, bridge 1700 configured in an upright position such that support 1710 is substantially vertical and does not significantly (or not at all) increase the footprint of the MRI system. As a result, bridge 1700 does not impede moving the portable MRI system along the hallway and through the doorway. Fig. 17A also shows a deployable guard 10040, the guard 10040 being in a deployed position to indicate a 5-gauss line for the MRI system when the MRI system is being transported or stored or otherwise not in use. As discussed in U.S. application No.16/389004 entitled "deployable shield for a portable magnetic resonance imaging device" (the contents of which are incorporated herein by reference in their entirety) filed on 19/4/2019, when an MRI system is moved to different locations, the shield may be deployed to demarcate a physical boundary within which a magnetic field is above a specified magnetic field strength to provide a visual signal about the magnetic field. Further, as shown in fig. 17B, when the bridge 1700 is erected, the bridge provides a barrier to the imaging region of the MRI system where the magnetic field is strongest.

Fig. 17B shows portable MRI system 10000 with bridge 1700, bridge 1700 configured in a lowered position, and fig. 17C shows bridge 1700 deployed in the lowered position, bridge 1700 bridging the gap between patient bed 490 and MRI system 10000 to allow patient 499Is positioned within an imaging region of the MRI system and supports a patient 499 during imaging. Bridge 1700 may be bolted to B as described above₀A magnet to secure the bridge to the MRI system. For example, as shown in FIG. 17B, a portable MRI system 10000 includes B₀Magnet 10005, B₀The magnet 10005 comprises at least one first permanent B magnetically coupled to each other by a ferromagnetic yoke 10020₀Magnet 10010a and at least one second permanent B₀Magnet 10010b, ferromagnetic yoke 10020, is configured to capture and direct magnetic flux to increase the magnetic flux density within the imaging region 10065 (field of view) of the MRI system. For the exemplary MRI system 10000, the bridge 1700 is bolted to the lower magnet 10010B such that when the bridge is deployed (i.e., positioned in a lowered position as shown in fig. 17B and 17C), the support 1710 provides a continuation of the plane 10015 of the magnet housing, thereby facilitating positioning of the patient within the imaging region 10065 and providing a relatively level support for the patient during imaging. Fig. 17B also illustrates a transport mechanism 10080 of MRI system 10000 that facilitates moving the MRI system from one location to another, as discussed in further detail below.

Figure 17C illustrates a patient 499 positioned within the imaging zone of the MRI system 1000 for imaging the patient's head from a hospital bed 490. As shown, once the patient is positioned with the imaging region, and during imaging, the patient's head is supported by the helmet 10030 (which includes radio frequency transmit and receive coils), at least a portion of the patient's torso and arms are supported by the folding bridge 1700, and the remainder of the patient's weight is supported by the patient bed 490. As noted above, some embodiments of the folding bridge are sized and configured to support large and heavy patients. For example, bridge 1700 may be rated for a 500 pound patient with a safety factor of 2.5 or higher. According to some embodiments, for example, the various exemplary bridge configurations described above in connection with any of exemplary bridges 1400, 1500, or 1600 can be used, such that bridge 1700 can be rated for a 500 pound patient with a safety factor of 4.0 or greater (e.g., a safety factor of 4.3).

As described above, the portable MRI system 10000 includes a transport mechanism configured to allow the portable MRI system to be transported to a desired location. Referring to fig. 17B, the portable MRI system 10000 includes a transport mechanism 10080, the transport mechanism 10080 having a drive motor 10086 coupled to a drive wheel 10084. The transport mechanism 10080 may also include a plurality of casters 1082 to aid in support and stability and to facilitate transport of the MRI system. In this manner, the transport mechanism 10080 provides motorized assistance in transporting the MRI system 10000 to a desired location.

According to some embodiments, the transport mechanism 10080 comprises a motorized assist device controlled using a controller (e.g., a joystick or other human manipulatable controller) to guide the portable MRI system during transport to a desired location. According to some embodiments, the delivery mechanism includes a power assist component configured to detect when a force is applied to the MRI system and engage with the delivery mechanism to provide motorized assistance in the direction of the detected force. For example, the track 10050 shown in fig. 17B can be configured to detect when a force is applied to the track (e.g., by a person pushing the track) and engage with a drive motor to provide maneuvering assistance for driving the wheel in the direction of the applied force. As a result, the user may guide the portable MRI system with the assistance of the transport mechanism in response to the direction of the force applied by the user. The drive motor may be operated in other ways, such as via buttons, balls, or other suitable mechanisms located on the MRI system, or using touch screen controls on the mobile computing device 10025 communicatively coupled to the MRI system, as the aspect of motorized control is not limited in this respect.

Thus, a low-field MRI system 10000 equipped with a folding bridge 1700 can be used for point-of-care MRI for patients including large and heavy patients. For example, to perform point-of-care MRI on a patient from a standard medical couch, the MRI system and couch may be positioned close to each other. In some embodiments, the MRI system is portable and can be moved to a location near a hospital bed by medical personnel pushing the MRI system into position and/or using a motor-driven transport system to move the MRI system into position. In some cases, it may be desirable to transport the MRI system from another room or unit within the hospital. In other cases, the MRI system may already be in the same room as the patient and only need to be moved to the side of the patient's bed. In other cases, the couch is transported to the MRI system and moved to a position proximate the MRI system for imaging. During positioning of the MRI system and patient bed adjacent to each other, the folding bridge attached to the MRI system may be positioned in a vertical or erect position (e.g., in the vertical position shown in fig. 17A) to facilitate transporting the system along a hallway and/or through a doorway and/or to facilitate positioning the MRI system and bed in a close position (e.g., positioning the MRI system and a bed foot or head adjacent to each other).

Once the MRI system and couch are positioned proximate to each other, the folding bridge may be moved from the vertical position to the horizontal position such that the bridge at least partially overlaps the couch (e.g., the folding bridge 1700 may be moved from the vertical position shown in fig. 17A to the horizontal position shown in fig. 17B and 17C). The folding bridge then provides a surface that bridges the gap between the MRI system and the couch, where the patient can move. For example, a portion of the anatomy of a patient to be imaged can be positioned within an imaging region of an MRI system via a bridge, and the bridge can provide support to the patient during and after positioning the patient within the imaging region. After positioning the patient within the MRI system, at least one magnetic resonance image of the portion of the anatomy of the patient may be acquired with the patient at least partially supported by the couch and at least partially supported by the bridge (e.g., as shown in fig. 17C). In this way, point-of-care MRI can be performed.

Having thus described various aspects and embodiments of the technology set forth in this disclosure, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be within the spirit and scope of the technology described herein. For example, various other means and/or structures for performing the function and/or obtaining the result and/or one or more of the advantages described herein will be readily apparent to those of ordinary skill in the art, and each such variation and/or modification is considered to be within the scope of the embodiments described herein. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, embodiments of the invention may be practiced otherwise than as specifically described. In addition, any combination of two or more features, systems, articles, materials, kits, and/or methods described herein may be included within the scope of the present disclosure if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent.

The above-described embodiments may be implemented in any of numerous ways. One or more aspects and embodiments of the present disclosure relating to the performance of a process or method may be implemented using program instructions executable by a device (e.g., a computer, processor, or other device) to perform or control the performance of a process or method. In this regard, the various inventive concepts may be embodied in a computer-readable storage medium (or multiple computer-readable storage media) (e.g., a computer memory in a field programmable gate array or other semiconductor device or other tangible computer storage medium, one or more floppy discs, optical discs, magnetic tapes, flash memories, circuit arrangements) encoded with one or more programs that, when executed on one or more computers or other processors, perform methods that implement one or more of the various embodiments described above. The computer-readable medium or media can be transportable, such that the program or programs stored thereon can be loaded onto one or more different computers or other processors to implement the various aspects described above. In some implementations, the computer-readable medium may be a non-transitory medium.

The terms "program" or "software" are used herein in a generic sense to refer to any type of computer code or set of computer-executable instructions that can be employed to program a computer or other processor to implement various aspects as described above. Further, it should be understood that according to one aspect, when performing a method of the present disclosure, one or more computer programs need not reside on a single computer or processor, but may be distributed in a modular fashion amongst a number of different computers or processors to implement various aspects of the present disclosure.

Computer-executable instructions may take many forms, such as program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, elements, data structures, etc. that perform particular tasks or implement particular abstract data types. Typically, the functionality of the program modules may be combined or distributed as desired in various embodiments.

In addition, the data structures may be stored in any suitable form on a computer readable medium. For simplicity of illustration, the data structure may be shown with fields that are associated by location in the data structure. Likewise, such relationships may be implemented by allocating storage for fields using locations in a computer-readable medium that convey relationships between fields. However, any suitable mechanism may be used to establish a relationship between information in fields of a data structure, including through the use of pointers, identifiers, or other mechanisms that establish a relationship between data elements.

The above-described embodiments of the present invention can be implemented in any of numerous ways. For example, embodiments may be implemented using hardware, software, or a combination thereof. When implemented in software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single computer or distributed among multiple computers. It should be understood that any component or collection of components that perform the functions described above can be generically considered as a controller that controls the above-described functions. The controller can be implemented in numerous ways, such as with dedicated hardware or with general purpose hardware (e.g., one or more processors) that is programmed by microcode or software to perform the functions recited above, and when the controller corresponds to multiple components of a system, the controller can be implemented in a combination of numerous ways.

Additionally, it should be appreciated that a computer may be implemented in any of a number of forms, such as a rack-mounted computer, a desktop computer, a laptop computer, or a tablet computer, as non-limiting examples. Further, a computer may be embedded in a device not normally considered a computer but with suitable processing capabilities, including a Personal Digital Assistant (PDA), a smart phone, or any other suitable portable or stationary electronic device.

In addition, a computer may have one or more input and output devices. These devices may be used to present, among other things, a user interface. Examples of output devices that may be used to provide a user interface include printers or displays for visual presentation of output and speakers or other sound generating devices for audible presentation of output. Examples of input devices that may be used for the user interface include keyboards, and pointing devices (such as mice, touch pads, and digitizing tablets). As another example, a computer may receive input information through speech recognition or other audible format.

Such computers may be interconnected by one or more networks IN any suitable form, including as local area networks or wide area networks, such as enterprise and Intelligent Networks (IN) or the Internet. Such networks may be based on any suitable technology, may operate according to any suitable protocol, and may include wireless networks, wired networks, or fiber optic networks.

Further, as illustrated, some aspects may be implemented as one or more methods. The actions performed as part of the method may be ordered in any suitable way. Thus, embodiments may be configured to perform acts in an order different than illustrated, which may include some acts that may be performed concurrently, even though shown as sequential acts in illustrative embodiments.

All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.

The indefinite articles "a" and "an" as used herein in the specification and the claims are to be understood to mean "at least one" unless clearly indicated to the contrary.

The phrase "and/or" as used herein in the specification and claims should be understood to mean "one or two" of the elements associated together, i.e., the elements appear in some instances in conjunction with and in other instances are separate elements. Multiple elements listed with "and/or" should be interpreted in the same manner, i.e., "one or more" of the elements so associated. In addition to elements specifically identified by the "and/or" clause, other elements may alternatively be present, whether related or unrelated to those specifically identified elements. Thus, as a non-limiting example, when used in conjunction with open language such as "including," references to "a and/or B" may refer in one embodiment to only a (optionally including elements other than B); in another embodiment, only B (optionally including elements other than a); in yet another embodiment, to a and B (optionally including other elements); and so on.

As used herein in the specification and claims, the phrase "at least one," when referring to a list of one or more elements, should be understood to mean at least one element selected from one or more elements in the list of elements, but not necessarily including at least one of all elements specifically listed in the list of elements, and not excluding any combination of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified in the list of elements to which the phrase "at least one" refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, "at least one of a and B" (or, equivalently, "at least one of a or B," or, equivalently "at least one of a and/or B") can be referred to in one embodiment as at least one, optionally including more than one, a, and the absence of B (and optionally including elements other than B); in another embodiment, reference may be made to at least one, optionally including more than one, B, and the absence of a (and optionally including elements other than a); in yet another embodiment, reference may be made to the case of at least one, optionally including more than one, a and at least one, optionally including more than one, B (and optionally including other elements); and so on.

Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," or "having," "containing," "involving," and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

In the claims, as well as in the specification above, all transitional phrases such as "comprising," "carrying," "having," "containing," "involving," "holding," "consisting of," and the like are to be understood to be open-ended, i.e., to mean including but not limited to. The transition phrases "consisting of … …" and "consisting essentially of … …" alone should be closed or semi-closed transition phrases, respectively.