阅读说明：本技术 一种用于磁共振成像的具有适形能力的射频线圈结构 (Radio frequency coil structure with conformal capability for magnetic resonance imaging ) 是由 张松涛 谢斌 沈江 林海洋 何钧 于 2021-06-29 设计创作，主要内容包括：本发明涉及磁共振技术领域,具体地说是一种用于磁共振成像的具有适形能力的射频线圈结构。一种用于磁共振成像的具有适形能力的射频线圈结构,包括线圈刚性塑料外壳,其特征在于：位于线圈刚性塑料外壳的外缘均布设有若干通孔；位于线圈刚性塑料外壳的内部与磁共振成像区域之间均布设有若干通道模块,相邻的通道模块相互交叠连接。同现有技术相比,提供一种用于磁共振成像的具有适形能力的射频线圈结构,突破了传统磁共振刚性射频线圈成像区域尺寸不能变化的限制,为磁共振射频线圈更巧妙的设计和更灵活的应用开辟了可能性。(The invention relates to the technical field of magnetic resonance, in particular to a radio frequency coil structure with conformal capability for magnetic resonance imaging. A radio frequency coil structure with conformality for magnetic resonance imaging, comprising a coil rigid plastic housing, characterized by: a plurality of through holes are uniformly distributed on the outer edge of the rigid plastic shell of the coil; a plurality of channel modules are uniformly distributed between the interior of the rigid plastic shell of the coil and the magnetic resonance imaging area, and adjacent channel modules are connected in an overlapping mode. Compared with the prior art, the radio frequency coil structure with the conformal capability for the magnetic resonance imaging is provided, the limitation that the size of the imaging area of the traditional magnetic resonance rigid radio frequency coil cannot be changed is broken through, and the possibility is opened up for the more ingenious design and the more flexible application of the magnetic resonance radio frequency coil.)

1. A radio frequency coil structure with conformality for magnetic resonance imaging, comprising a coil rigid plastic housing, characterized by: a plurality of through holes are uniformly distributed on the outer edge of the rigid plastic shell (1) of the coil; a plurality of channel modules (2) are uniformly distributed between the interior of the rigid plastic shell (1) of the coil and a magnetic resonance imaging area, and the adjacent channel modules (2) are connected in an overlapping mode.

2. A radio frequency coil structure with conformality for magnetic resonance imaging according to claim 1, wherein: the channel module (2) is a single-channel module or a multi-channel module.

3. A radio frequency coil structure with conformality for magnetic resonance imaging according to claim 2, wherein: the single-channel module comprises a sheet structure, a rigid module and a rigid handle-shaped structure, wherein the upper end of the sheet structure (2-1) is connected with the rigid handle-shaped structure (2-3) through the rigid module (2-2), and one sheet structure (2-1) is arranged.

4. A radio frequency coil structure with conformality for magnetic resonance imaging according to claim 2, wherein: the multichannel module comprises sheet structures, rigid modules and rigid handle-shaped structures, wherein the sheet structures (2-1) are mutually overlapped and connected, and the rigid handle-shaped structures (2-3) are connected through the rigid modules (2-2) at the overlapped centers of the sheet structures (2-1); at least two sheet structures (2-1) are arranged.

5. A radio frequency coil structure with conformality for magnetic resonance imaging according to claim 3 or 4, wherein: the slice structure (2-1) is a flexible structure or a rigid structure, and a resonance loop of the magnetic resonance radio frequency coil is arranged in the slice structure (2-1).

6. A radio frequency coil structure with conformality for magnetic resonance imaging according to claim 5, wherein: the resonance circuit in the flake structure (2-1) comprises a resonance circuit conductor and a resonance circuit connecting lead, and the resonance circuit conductor (2-4) is connected with the rigid module (2-2) through the resonance circuit connecting lead (2-5).

7. A radio frequency coil structure with conformality for magnetic resonance imaging according to claim 6, wherein: the resonant circuit connecting lead (2-5) is connected with the resonant circuit conductor (2-4) and the rigid module (2-2) in one way or multiple ways.

8. A radio frequency coil structure with conformality for magnetic resonance imaging according to claim 6, wherein: the resonant circuit conductor (2-4) is a flexible printed circuit board, the flexible printed circuit board comprises an insulating medium and a planar flexible capacitor, the insulating medium is connected with the planar flexible capacitor, and the planar flexible capacitor is connected with the rigid module (2-2) through a resonant circuit connecting lead (2-5).

9. A radio frequency coil structure with conformality for magnetic resonance imaging according to claim 8, wherein: the flexible printed circuit board comprises an insulating medium and a distributed flexible capacitor, wherein the distributed flexible capacitor is connected to the insulating medium and is connected with the rigid module (2-2) through a resonant circuit connecting lead (2-5).

10. A radio frequency coil structure with conformality for magnetic resonance imaging according to claim 9, wherein: the distributed flexible capacitor comprises an upper conductor and a lower conductor, wherein the upper surface and the lower surface of an insulating medium are respectively connected with the upper conductor and the lower conductor, and two ends of the adjacent upper conductor and two ends of the adjacent lower conductor are connected in an overlapping mode.

11. A radio frequency coil structure with conformality for magnetic resonance imaging according to claim 3, wherein: the rigid handle-shaped structure (2-3) is vertically connected with the center or one side of the center of the thin sheet structure (2-1).

12. A radio frequency coil structure with conformality for magnetic resonance imaging according to claim 3 or 4, wherein: the rigid handle-shaped structure (2-3) is internally provided with a detuning circuit, a common mode rejection balun and a preamplifier of the magnetic resonance radio frequency coil.

13. A radio frequency coil structure with conformality for magnetic resonance imaging according to claim 3 or 4, wherein: and a tuning capacitor of the magnetic resonance radio frequency coil is arranged in the rigid module (2-2).

14. A radio frequency coil structure with conformality for magnetic resonance imaging according to claim 1, wherein: the rigid plastic shell (1) of the coil is of one of a cylindrical structure, a spherical structure, a planar structure and an arc-surface structure.

15. A radio frequency coil structure with conformality for magnetic resonance imaging according to claim 1 or 2, wherein: the plurality of channel modules (2) are overlapped in pairs to form one of an annular structure, a spherical structure, a planar structure and an arc-shaped surface structure.

16. A radio frequency coil structure with conformality for magnetic resonance imaging according to claim 1, wherein: the channel module (2) penetrates through a through hole of the rigid coil plastic shell (1) through a rigid handle-shaped structure (2-3) and is connected with the rigid coil plastic shell (1).

Technical Field

The invention relates to the technical field of magnetic resonance, in particular to a radio frequency coil structure with conformal capability for magnetic resonance imaging.

Background

Magnetic resonance imaging is an advanced technique for non-destructive imaging of the human body and is widely applied to diagnosis of diseases of various parts of the human body. The performance of the magnetic resonance radio frequency coil, which is an important component of the magnetic resonance imaging system, directly determines the quality of the magnetic resonance imaging.

According to the physical law, when the magnetic resonance radio frequency coil detects the magnetic resonance radio frequency signals emitted by the human body, the closer the magnetic resonance radio frequency coil to the human body, the better the magnetic resonance radio frequency coil is. The traditional radio frequency coil is a hard coil, and a radio frequency loop formed by a conductor, a capacitor, an inductor and the like is directly attached to a hard plastic shell, so that the coil is convenient to manufacture and use. However, since the shape and size of the coil cannot be changed, the same coil may be too small for a part of the patient to be placed, and too large for another part of the patient to cause the radio frequency loop to be far away from the human body, resulting in a decrease in the signal-to-noise ratio and image quality. Furthermore, the same part of the human body, such as the head and the neck, can be very different from patient to patient in shape, which makes the coil applicability problem more serious.

Therefore, how to make the same coil suitable for patients with different shapes and sizes and obtain excellent image quality is a troublesome problem to be solved by the magnetic resonance radio frequency coil engineer.

Disclosure of Invention

The invention overcomes the defects of the prior art, provides the radio frequency coil structure with the conformal capability for the magnetic resonance imaging, breaks through the limitation that the size of the imaging area of the traditional magnetic resonance rigid radio frequency coil cannot be changed, and opens up the possibility for the more ingenious design and the more flexible application of the magnetic resonance radio frequency coil.

To achieve the above object, a radio frequency coil structure with conformality for magnetic resonance imaging is designed, which includes a rigid plastic housing of a coil, and is characterized in that: a plurality of through holes are uniformly distributed on the outer edge of the rigid plastic shell of the coil; a plurality of channel modules are uniformly distributed between the interior of the rigid plastic shell of the coil and the magnetic resonance imaging area, and adjacent channel modules are connected in an overlapping mode.

The channel module is a single-channel module or a multi-channel module.

The single-channel module comprises a sheet structure, a rigid module and a rigid handle-shaped structure, wherein the upper end of the sheet structure is connected with the rigid handle-shaped structure through the rigid module, and one sheet structure is arranged.

The multi-channel module comprises sheet structures, rigid modules and rigid handle-shaped structures, wherein the sheet structures are mutually overlapped and connected, and the rigid handle-shaped structures are connected through the rigid modules at the overlapped centers of the sheet structures; the number of the sheet structures is at least two.

The slice structure is a flexible structure or a rigid structure, and a resonance loop of the magnetic resonance radio frequency coil is arranged in the slice structure.

The resonance circuit in the flake structure comprises a resonance circuit conductor and a resonance circuit connecting lead, and the resonance circuit conductor is connected with the rigid module through the resonance circuit connecting lead.

The resonant circuit connecting lead is one or more paths of connecting resonant circuit conductors and the rigid module.

The resonant circuit conductor is a flexible printed circuit board, the flexible printed circuit board comprises an insulating medium and a planar flexible capacitor, the insulating medium is connected with the planar flexible capacitor, and the planar flexible capacitor is connected with the rigid module through a resonant circuit connecting lead.

The flexible printed circuit board comprises an insulating medium and a distributed flexible capacitor, wherein the distributed flexible capacitor is connected to the insulating medium and is connected with the rigid module through a resonant circuit connecting lead.

The distributed flexible capacitor comprises an upper conductor and a lower conductor, wherein the upper surface and the lower surface of an insulating medium are respectively connected with the upper conductor and the lower conductor, and two ends of the adjacent upper conductor and two ends of the adjacent lower conductor are connected in an overlapping mode.

The rigid handle-like structure is perpendicularly connected with the center or one side of the center of the thin sheet structure.

The rigid handle-shaped structure is internally provided with a detuning circuit, a common mode rejection balun and a preamplifier of the magnetic resonance radio frequency coil.

And a tuning capacitor of the magnetic resonance radio frequency coil is arranged in the rigid module.

The rigid plastic shell of the coil is of one of a cylindrical structure, a spherical structure, a planar structure and an arc-surface structure.

The plurality of channel modules are overlapped in pairs to form one of an annular structure, a spherical structure, a planar structure and an arc-shaped structure.

The channel module penetrates through the through hole of the rigid plastic shell of the coil through the rigid handle-shaped structure and is connected with the rigid plastic shell of the coil.

Compared with the prior art, the invention provides the radio frequency coil structure with the conformal capability for the magnetic resonance imaging, breaks through the limitation that the size of the imaging area of the traditional magnetic resonance rigid radio frequency coil cannot be changed, and opens up the possibility for the more ingenious design and the more flexible application of the magnetic resonance radio frequency coil.

The invention has simple structure and flexible operability, and can adjust the position of each module along the radial direction according to the shape and the size of the part to be detected of the human body, thereby enabling the coil to adapt to patients with different sizes and shapes and to be attached to the part to be detected as much as possible, and further obtaining higher signal-to-noise ratio and image quality.

Drawings

Fig. 1 and fig. 2 are schematic structural views of the present invention.

Fig. 3 is a side view of the single channel module configuration of the present invention.

Fig. 4 is a top view of the single channel module structure of the present invention.

Figure 5 is a top view of another configuration of a single channel module of the present invention.

Fig. 6 is a structural diagram of a multi-channel module.

Referring to fig. 1 and 5, 1 is a rigid plastic shell of a coil, 2 is a channel module, 2-1 is a sheet structure, 2-2 is a rigid module, 2-3 is a rigid handle-shaped structure, 2-4 is a resonant circuit conductor, and 2-5 is a resonant circuit connecting lead.

Detailed Description

The invention is further illustrated below with reference to the accompanying drawings.

As shown in fig. 1 to 6, a plurality of through holes are uniformly distributed at the outer edge of the coil rigid plastic shell 1; a plurality of channel modules 2 are uniformly distributed between the interior of the rigid plastic shell 1 of the coil and a magnetic resonance imaging area, and the adjacent channel modules 2 are connected in an overlapping mode.

The channel module 2 is a single-channel module or a multi-channel module.

The single-channel module comprises a sheet structure, a rigid module and a rigid handle-shaped structure, wherein the upper end of the sheet structure 2-1 is connected with the rigid handle-shaped structure 2-3 through the rigid module 2-2, and one sheet structure 2-1 is arranged.

The multi-channel module comprises a sheet structure, a rigid module and a rigid handle-shaped structure, wherein a plurality of sheet structures 2-1 are mutually overlapped and connected, and the rigid handle-shaped structure 2-3 is connected at the overlapped center of the plurality of sheet structures 2-1 through the rigid module 2-2; at least two sheet structures 2-1 are provided.

The sheet structure 2-1 is a flexible structure or a rigid structure, and a resonance loop of the magnetic resonance radio frequency coil is arranged in the sheet structure 2-1.

The resonant tank in the laminar structure 2-1 comprises a resonant tank conductor, a resonant tank connecting lead, the resonant tank conductor 2-4 being connected to the rigid module 2-2 by a resonant tank connecting lead 2-5.

The resonant circuit connecting lead 2-5 is connected with the resonant circuit conductor 2-4 and the rigid module 2-2 in one way or multiple ways.

The resonant circuit conductor 2-4 is a flexible printed circuit board, the flexible printed circuit board comprises an insulating medium and a planar flexible capacitor, the insulating medium is connected with the planar flexible capacitor, and the planar flexible capacitor is connected with the rigid module 2-2 through a resonant circuit connecting lead 2-5.

The flexible printed circuit board comprises an insulating medium and a distributed flexible capacitor, wherein the distributed flexible capacitor is connected to the insulating medium and is connected with the rigid module 2-2 through a resonant circuit connecting lead 2-5.

The distributed flexible capacitor comprises an upper conductor and a lower conductor, wherein the upper surface and the lower surface of an insulating medium are respectively connected with the upper conductor and the lower conductor, and two ends of the adjacent upper conductor and two ends of the adjacent lower conductor are connected in an overlapping mode.

The rigid handle-like structure 2-3 is attached perpendicularly to the center or one side of the center of the sheet structure 2-1.

The rigid handle-shaped structure 2-3 is internally provided with a detuning circuit, a common mode rejection balun and a preamplifier of the magnetic resonance radio frequency coil.

The rigid module 2-2 is internally provided with a tuning capacitor of the magnetic resonance radio frequency coil.

The rigid plastic shell 1 of the coil is one of a cylindrical structure, a spherical structure, a planar structure and a cambered surface structure.

The plurality of channel modules 2 form one of an annular structure, a spherical structure, a planar structure and an arc-shaped structure through two-two overlapping.

The channel module 2 is connected with the rigid plastic shell 1 of the coil through a through hole of the rigid handle-like structure 2-3 penetrating through the rigid plastic shell 1 of the coil.

As shown in fig. 3 and 4, is a schematic diagram of a single channel module. The single-channel resonant tank conductor 2-4 is circular with a diameter of 60mm and is made using a flexible printed circuit board. The tuning capacitor of the resonant circuit is made of ceramic capacitor, all detuning circuits, tuning capacitors, feed-in point capacitors and the like are placed in the middle rigid handle-shaped structure 2-3, so that a plurality of pairs of adjacent resonant circuit connecting wires 2-5 are needed to connect the resonant circuit with the detuning circuits, the tuning capacitors and the signal feed-in point capacitors which are positioned in the central rigid part, and the wires are close to each other one by one to reduce the influence of the radio frequency magnetic field generated by the whole circular resonant circuit as much as possible.

The flexible printed wiring board is partially encapsulated in a foil structure 2-1 having a curvature. The rigid stem structure 2-3 portion includes, in addition to a detuning circuit, a tuning capacitor, and a signal feed-in point capacitor, a common mode rejection balun and a preamplifier, with the signal feed-in point capacitor connected to the preamplifier through the common mode rejection balun. All of the electronic components and assemblies within the rigid stem-like structure 2-3 described above are enclosed within a rigid plastic housing.

As shown in fig. 1 and fig. 2, 10 single-channel modules are uniformly arranged in a circle and are arranged in a staggered manner. The outermost layer is provided with a rigid plastic shell 1 of the coil, and a rigid handle-shaped structure 2-3 of the single-channel module penetrates through the rigid plastic shell 1 of the coil and can have a certain moving space in the radial direction. Fig. 1 shows that all single-channel modules are tuned to be closest to the center, i.e. when the whole coil is shrunk to the minimum, where the overlapping width between two adjacent channels is about 19mm, which is larger than the optimal overlapping width (about 15 mm), and where the mutual inductance of two channels is about 6 nH. Although this will result in a certain reduction of the snr of each channel, the reduction of the snr is not so severe due to the use of the low input impedance preamplifier and can be controlled within 10%. At this point, all 10 single channel modules enclosed a cylinder with a diameter of about 12 cm.

Fig. 2 shows the state in which all single-channel modules are tuned to be farthest away from the center, i.e. when the whole coil is maximally expanded, in which the width of the overlap between the channels of the coil is 8mm, which is smaller than its optimal width of overlap (about 15 mm), when the mutual inductance of the two channels is about-7 nH. Although this will result in a certain reduction of the snr of each channel, the reduction of the snr is not so severe due to the use of the low input impedance preamplifier and can be controlled within 10%. At this point, all 10 single-channel modules enclosed a cylinder with a diameter of about 16 cm.

Thus, the smallest imaging area of the coil is a cylinder with the diameter of 12cm, the largest imaging area of the coil is a cylinder with the diameter of 16cm, the requirements of adult knee joint magnetic resonance imaging with different sizes can be met, and the coil can perfectly fit the knee joint part of a patient under various conditions, so that the highest signal-to-noise ratio and the highest image quality are obtained.

In addition, figures 1 and 2 are only the two most extreme cases, and fit perfectly regardless of any shape, as long as the patient's knee size is between the two extremes. The human knee joint is usually narrower in the left and right directions and wider in the front and back directions, and can adapt to different shapes because each channel is independently adjusted.

This embodiment only demonstrates the situation when 10 channels are made into one turn, and there can be more channels arranged into multiple turns, which can cover a larger imaging area.

For the magnetic resonance imaging of the human head, a plurality of channel modules can be wrapped into an approximate spherical surface, and the rigid handle-shaped structure of each channel module is adjusted along the normal direction of the spherical surface, so that the channel module can be used for imaging the human body part with a more complex curved surface.

In some cases, if the partially covered area is relatively flat and has multiple channels, such as the left or right side of the human body, it is also possible to make two or three channels in a single module, but still place the rigid handle-like structure in the central region of the channels. This may reduce the complexity of the adjustment.

The position of the rigid handle-shaped structure can be adjusted independently by hands, and structures such as springs and the like can also be used, the springs prop the independent modules into a smaller space towards the inside of the coil in a natural state, and when the coil is buckled on the body of a patient such as a knee joint in use, the independent modules are propped outwards by the knee joint. Thereby ensuring that each module is in close contact with the human body.

The sheet structure of each individual module can be made flexible or rigid. The flexibility and the comfort are good, the rigidity and the reliability are good, and the manufacture is more convenient.

Preferably, as shown in fig. 5, the single-channel module shown in fig. 4 can be modified into the structure shown in fig. 5 by using a planar flexible distributed capacitance technology made of a double-layer flexible printed circuit board. The double-layer flexible printed circuit board consists of an upper conductor, an intermediate insulating medium layer and a lower conductor, and two layers of insulating medium protective films can be arranged on the outermost layer. The most common flexible printed wiring board substrate is polyimide. The upper conductor and the lower conductor with certain overlapping areas and the insulating medium layer positioned in the middle can form a planar flexible distributed capacitor. This capacitance can be used to replace the discrete ceramic capacitance used in the conventional magnetic resonance radio frequency coil of figure 4. Since these capacitors are themselves planar flexible structures, there is no longer a need to place them in rigid parts as in fig. 4 and to use connection lines for connection. Except for its detuning circuit part, which still requires the use and soldering of separate components such as diodes, it is still necessary to place it in a rigid part and connect it with the resonant tank using connecting wires. The pre-amplifiers and common-mode rejection balun of the coil still need to be placed in the rigid part.