Highly fitting helmet-type primate magnetic resonance experiment radio frequency coil device

Abstract

The present application discloses a high-fitting helmet-type primate magnetic resonance experiment radio frequency coil device, comprising: an animal fixing seat for fixing the animal to be tested, a helmet-type coil support shell connected to the animal fixing seat through a universal connecting rod and capable of being worn on the head of the animal to be tested, a radio frequency receiving coil arranged inside the coil support shell, and a signal wire connected to the radio frequency receiving coil circuit and extending outside the coil support shell. Regardless of the angle at which the head of the animal to be tested is fixed, the radio frequency receiving coil in the device can be arranged close to the scalp of the animal to be tested, thereby improving the signal-to-noise ratio of signal induction reception and the quality of magnetic resonance imaging. Regardless of the angle at which the head of the animal to be tested is fixed, the radio frequency receiving coil in the device can be arranged close to the scalp of the animal to be tested, thereby improving the signal-to-noise ratio of signal induction reception and the quality of magnetic resonance imaging.

Description

Technical Field

[0001] The present application relates to the field of magnetic resonance imaging, and in particular to a highly-fitting helmet-type radio frequency coil device for primate magnetic resonance experiments. Background Art

[0002] As a truly non-invasive imaging technology, magnetic resonance imaging is widely used in brain science and brain disease research. Its basic principle is that under the action of the main magnetic field (external magnetic field), some protons (including hydrogen protons in the human body) that precess around the main magnetic field (external magnetic field) will increase their precession angle under the action of short-term radio frequency waves; when the radio frequency waves stop, those protons will gradually return to their original state and release radio frequency signals with the same frequency as the excitation wave at the same time, resulting in nuclear magnetic resonance. Magnetic resonance imaging technology uses this principle to selectively excite the nuclei in the human body at the required position by adding a pulse gradient magnetic field to the main magnetic field, and then receive the nuclear magnetic resonance signals generated by the nuclei, and finally perform Fourier transform in the computer to frequency encode and phase encode these signals, thereby establishing a complete magnetic resonance image.

[0003] In magnetic resonance imaging systems, the uniformity of the magnetic field generated by the transmitting coil and the receiving coil is a key factor in obtaining high-quality images. In conventional magnetic resonance imaging systems, an integral radio frequency coil is often used to obtain the best excitation field uniformity. Commonly used body coils include birdcage, solenoid, and saddle coils. The birdcage coil can meet the requirements of uniformity of the transmitting magnetic field within the human body. The body transmitting coil of this design is integrated into a conventional field strength magnetic resonance system as a conventional configuration to meet the imaging requirements of any part. The solenoid coil will generate a vibrating magnetic field parallel to the coil axis, which is more suitable for a magnetic field system with a vertical static magnetic field, but not for an instrument with a patient bracket perpendicular to the static magnetic field. The field uniformity generated by the saddle coil is relatively good, but it is greatly affected by the symmetry of the magnet and is extremely sensitive to the radio frequency environment. Therefore, the magnetic resonance imaging system can only be made into a relatively closed cylindrical or other similar shapes, but such a shape will bring serious psychological pressure to patients with depression, claustrophobia or other similar diseases.

[0004] However, if a larger coil is used for reception at the same time, a lower signal-to-noise ratio will be generated. This is because the receiving coil and the signal-generating tissue involved in imaging are far apart. In magnetic resonance imaging systems, a high signal-to-noise ratio is an important factor in ensuring high-quality images. Therefore, a dedicated coil is often used for RF reception to improve the signal-to-noise ratio of the required detection part. Compared with body coils, surface coils have higher sensitivity. When imaging local areas such as the spine and orbits, because the surface coil only detects the nuclear magnetic resonance signal of a small part of the tissue close to the coil, the surface coil has a better signal-to-noise ratio than the ordinary body coil. However, the RF intensity generated by the surface coil as a transmitting coil varies with depth, and is often manifested as image signal inhomogeneity. In addition, if a single larger surface coil is used to image a larger area, the noise of all areas covered by the coil will enter the coil, resulting in a poor signal-to-noise ratio. Using multi-channel array coil technology, multiple independent small coils cover the area together, so that only the noise of a small area near the coil can enter the coil, thereby meeting the requirements for obtaining high signal-to-noise ratio images within a large imaging range. At the same time, multi-channel array coil technology can be used in conjunction with parallel imaging technology to accelerate image acquisition and improve image quality.

[0005] However, for MRI experiments in brain science research on monkeys, which are very similar to humans in genetics, physiology, neuroanatomy and behavior, most of them are currently carried out on MRI systems dedicated to small animals. In this way, it is difficult to directly compare the data obtained in different MRI systems (small animal-specific MRI systems and clinical MRI systems for human imaging), that is, it is difficult to compare the results of cross-species research. Therefore, the development of a monkey RF coil device that can be used in a clinical MRI system will provide a basis for the ultimate clinical transformation of animal research results. In addition, considering that the temporal muscles on both sides of the monkey's head are relatively thick, the general surface coil will show a lower signal-to-noise ratio because it is far away from the imaging area on both sides of the temporal lobe of the monkey's head. Therefore, designing a RF coil that fits the monkey's brain will be conducive to obtaining images with a higher signal-to-noise ratio.

[0006] Normally, the magnetically compatible device for fixing the monkey's head is often relatively closed and has a small operating space. When using the above device for experiments, it is generally only equipped with a single-loop surface coil, and it is impossible to obtain high-quality magnetic resonance images. In addition, in order to prevent monkeys from moving during magnetic resonance scanning, monkeys are often anesthetized. However, in brain science research, it is often necessary to collect images of the monkey's whole brain activity in resting and task states, so the monkey needs to remain awake. Therefore, it is necessary to develop a relatively open radio frequency coil device that can be flexibly adjusted and specially used for fixing the monkey's head, which will bring convenience to magnetic resonance imaging of awake and anesthetized monkeys. Summary of the invention

[0007] The purpose of this application is to propose a high-fitting helmet-type primate magnetic resonance experiment radio frequency coil device in response to the above-mentioned problems. No matter at what angle the head of the animal being tested is fixed, the radio frequency receiving coil in the device can be arranged close to the scalp of the animal being tested, thereby improving the signal-to-noise ratio of signal induction reception and the quality of magnetic resonance imaging.

[0008] The technical solution of this application is:

[0009] A highly fitting helmet-type primate magnetic resonance experiment radio frequency coil device, comprising:

[0010] Animal holder for fixing the animal to be tested.

[0011] A helmet-shaped coil support shell connected to the animal holder via a universal connecting rod and capable of being worn on the head of the animal being tested,

[0012] a radio frequency receiving coil arranged inside the coil support shell, and

[0013] A signal wire is connected to the radio frequency receiving coil circuit and extends out of the coil supporting shell.

[0014] Based on the above technical solutions, this application also includes the following preferred solutions:

[0015] The animal holder comprises:

[0016] A support board for supporting the animal's body,

[0017] Two baffles are respectively fixed on the left and right sides of the animal body supporting plate,

[0018] Two ear bars are respectively mounted on the two baffles and extend horizontally from left to right.

[0019] two guide rods respectively fixed to the tops of the two baffles and extending horizontally frontward and rearward perpendicular to the ear bars, and

[0020] At least two rod clamps are respectively connected to the two guide rods and are adjustable in front and back at fixed positions on the guide rods;

[0021] A universal connecting rod is connected between each of the rod clamps and the coil supporting shell.

[0022] The universal connecting rod is made of plastic, and each guide rod is connected to two rod clamps distributed front and back. The universal connecting rod connected to the front rod clamp includes:

[0023] A first ball head tube, which is composed of a first tube body and a first hollow ball head integrally formed at one end of the first tube body, and the other end of the first tube body is fastened to the rod clamp by a first screw;

[0024] A second ball head tube, which is composed of a second tube body and a second hollow ball head integrally formed at one end of the second tube body, and the other end of the second tube body is fastened to the coil support shell by a second screw; and

[0025] The first ball-and-socket tube is composed of a third tube body and two first ball sockets respectively formed at two ends of the third tube body, and the first hollow ball head and the second hollow ball head are respectively interference-embedded in the two first ball sockets.

[0026] A first through hole is provided in the first ball head tube, and its two end openings are respectively located at the first tube body and the first hollow ball head; the other end of the first tube body is integrally provided with a circle of first annular inner flange located at the opening of one end of the first through hole and convex radially inward; a first positioning groove which is concave inward is integrally provided on the surface of the rod clamp; the other end of the first tube body is embedded in the first positioning groove; the screw rod of the first screw is locked into the rod clamp; the first annular inner flange is pressed and fixed between the screw head of the first screw and the rod clamp;

[0027] The second ball head tube is provided with a second through hole with openings at both ends located at the second tube body and the second hollow ball head respectively; the other end of the second tube body is integrally provided with a second annular inner flange located at the opening at one end of the second through hole and convex radially inwardly; the surface of the coil support shell is integrally provided with a second positioning groove recessed inwardly; the other end of the second tube body is embedded in the second positioning groove; the screw rod of the second screw is locked into the coil support shell; the second annular inner flange is pressed and fixed between the screw head of the second screw and the coil support shell.

[0028] The coil supporting shell comprises an inner shell wall and an outer shell wall which are detachably connected, the radio frequency receiving coil is arranged between the inner shell wall and the outer shell wall, and the second screw locks and fixes the inner shell wall and the outer shell wall.

[0029] An outlet wire protection tube is integrally arranged on the shell wall, and the signal wire is led out from the outlet wire protection tube.

[0030] The universal connecting rod connected to the rear rod clamp includes:

[0031] A third ball head tube, which is composed of a fourth tube body and a third hollow ball head integrally formed at one end of the fourth tube body, and the other end of the fourth tube body is fixedly connected to the rod clamp;

[0032] A second ball-and-socket tube, which is composed of a fifth tube body and two second ball-and-sockets respectively formed at two ends of the fifth tube body;

[0033] A first ball head and socket tube, which is composed of a sixth tube body, a third ball socket integrally formed at one end of the sixth tube body, and a fourth hollow ball head integrally formed at the other end of the sixth tube body, wherein the third hollow ball head and the fourth hollow ball head are respectively interference-embedded in the two second ball sockets;

[0034] A second ball head and socket tube, which is composed of a seventh tube body, a fourth socket integrally formed at one end of the seventh tube body, and a fifth hollow ball head integrally formed at the other end of the seventh tube body, wherein the fifth hollow ball head is interference fit in the third socket; and

[0035] A fourth ball head tube, which is composed of an eighth tube body and a sixth hollow ball head integrally formed at one end of the eighth tube body, the sixth hollow ball head is interference fit in the fourth ball socket, and the other end of the eighth tube body is fixedly connected to the coil support shell;

[0036] The eighth tube body is a right-angle structure, which is composed of a first tube segment and a second tube segment arranged vertically.

[0037] The radio frequency receiving coil comprises:

[0038] Left ear coil unit,

[0039] The right ear coil unit, and

[0040] The first coil unit group, the second coil unit group, the third coil unit group and the fourth coil unit group are arranged between the left ear coil unit and the right ear coil unit and arranged in sequence from front to back;

[0041] The first coil unit group is composed of four first coil units arranged in sequence from left to right, the second coil unit group is composed of three second coil units arranged in sequence from left to right and partially overlapped, the third coil unit group is composed of four third coil units arranged in sequence from left to right and partially overlapped, and the fourth coil unit group is composed of three fourth coil units arranged in sequence from left to right and partially overlapped;

[0042] Each of the second coil units is arranged to partially overlap with corresponding two adjacent first coil units and corresponding two adjacent third coil units;

[0043] The two fourth coil units at the left and right ends of the fourth coil unit group are respectively arranged to overlap with the two third coil units at the left and right ends of the third coil unit group;

[0044] The left ear coil unit is arranged to overlap with the first coil unit at the left end of the first coil group and the third coil unit at the left end of the third coil group;

[0045] The right ear coil unit is arranged to partially overlap with the first coil unit at the right end of the first coil group and the third coil unit at the right end of the third coil group.

[0046] The first coil unit, the second coil unit, the third coil unit and the fourth coil unit are all annular coils, and the left ear coil unit and the right ear coil unit are both saddle coils.

[0047] Any two or more of the three coil units that are partially overlapped have no common overlapping area.

[0048] This application has the following beneficial effects:

[0049] 1. The present application configures two mutually parallel guide rods on the animal holder, and each guide rod is connected to a rod clamp with adjustable position, and the rod clamp and the helmet-type coil support shell are connected to each other through a universal connecting rod. When in use, the connection position of the universal connecting rod and the animal holder can be adjusted by changing the front and rear position of the rod clamp on the guide rod, so that the relative position of the coil support shell and the animal holder can be adjusted over a wide range, and then the angle of the coil support shell and the position of the coil support shell can be adjusted by adjusting the connection scheduling of each rod segment of the universal connecting rod, so that it can be better worn and close to the animal's head, thereby improving the signal-to-noise ratio of signal induction reception and improving the quality of magnetic resonance imaging.

[0050] 2. Each rod section of the universal connecting rod is made of plastic parts with plastic deformation ability, and the adjacent rod sections are connected to each other by means of the ball head and ball socket structure. After assembly, the ball head and the ball socket are interference fit. In the natural state, the relative position of the two is fixed, so that the coil support shell is kept at a fixed angle. When the user applies a sufficiently large force to the ball head or the ball socket, the two will rotate relative to each other, thereby adjusting the placement angle of the coil support shell.

[0051] 3. The ball head on the corresponding rod section of the universal connecting rod is a hollow ball head. Compared with the solid ball head, the hollow ball head has a stronger plastic deformation ability, which facilitates the assembly of the universal connecting rod; and the hollow ball head uses less material, thereby reducing the material cost; at the same time, the hollow ball head has a small weight, thereby reducing the possibility of the universal connecting rod bending and deforming due to the gravity of the ball head.

[0052] 4. The same screw is responsible for the connection between the universal connecting rod and the coil support shell, and is also responsible for the fixed connection between the inner shell wall and the outer shell wall of the coil support shell, saving the number of parts and costs. Only after the universal connecting rod and the coil support shell are connected together, the inner shell wall and the outer shell wall will be fixed together to form a complete coil support shell, so the universal connecting rod and the coil support shell must be connected under normal conditions to prevent people from removing the universal connecting rod and ensure the exclusivity of the coil device.

[0053] 5. The wire protection tube integrated on the shell wall can not only provide structural protection for the signal wires, but also allow users to hold and move them.

[0054] 6. The positioning groove provided on the surface of the coil support shell not only facilitates the positioning and assembly of the universal connecting rod and the coil support shell, but also has a limiting effect on the universal connecting rod after the assembly is completed, preventing the connection end of the universal connecting rod and the coil support shell from deflecting and moving.

[0055] 7. The RF receiving coil in the coil support shell is composed of 16 coil units arranged in a specific way, with high imaging quality.

[0056] 8. The helmet-shaped coil support shell and the animal fixing seat are connected to each other through a universal connecting rod that can be bent and fixed, so that the coil support shell can assist the animal fixing seat to strengthen the fixing effect on the animal's head. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The present application is further described below with reference to the accompanying drawings and specific embodiments:

[0058] Figure 1 This is a schematic diagram of the three-dimensional structure of the radio frequency coil device in the first embodiment of the present application;

[0059] Figure 2 It is a schematic diagram of the three-dimensional structure of the radio frequency coil device in the first embodiment of the present application from another perspective;

[0060] Figure 3 This is a schematic diagram of the structure of the radio frequency receiving coil in the first embodiment of the present application;

[0061] Figure 4 This is a schematic diagram of the structure of the radio frequency receiving coil in Example 1 of the present application after the ear coil unit is disassembled;

[0062] Figure 5 This is a schematic diagram of the structure of the coil support shell of the radio frequency receiving coil in the first embodiment of the present application;

[0063] Figure 6 This is a structural schematic diagram of the coil support shell of the radio frequency receiving coil in the first embodiment of the present application from another perspective;

[0064] Figure 7 This is a schematic diagram of the connection structure between the first ball head tube and the rod clamp in the first embodiment of the present application;

[0065] Figure 8 for Figure 7 A cross-sectional view of

[0066] Fig. 9 for Figure 7 Exploded diagram of

[0067] Fig.10Schematic diagram of the connection structure between the first ball head and the first ball socket tube in the embodiment of the present application;

[0068] Fig.11 for Fig.10 A cross-sectional view of

[0069] Fig.12 This is a schematic diagram of the three-dimensional structure of the radio frequency coil device in the second embodiment of the present application;

[0070] Fig.13 This is a schematic structural diagram of the coil support shell portion of the radio frequency coil device in the second embodiment of the present application;

[0071] in:

[0072] 1 animal fixing seat, 2 universal connecting rod, 3 coil supporting shell, 4 radio frequency receiving coil, 5 signal wire, 6 first screw, 7 protective shell, 8 ear clearance hole;

[0073] 101 supporting plate, 102 baffle plate, 103 ear rod, 104 guide rod, 105 rod clamp, 106 locking screw;

[0074] 105a first positioning groove;

[0075] 201 a first ball head tube, 202 a second ball head tube, 203 a first ball socket tube, 204 a third ball head tube, 205 a second ball socket tube, 206 a first ball head socket tube, 207 a second ball head socket tube, 208 a fourth ball head tube;

[0076] 201a first tube body, 201b first hollow ball head, 201a-1 first annular inner flange;

[0077] 301 inner shell wall, 302 outer shell wall, 303 detection hole, 304 plug-in hole;

[0078] 301a second positioning groove, 302b outlet wire protection tube;

[0079] 401 is a first coil unit, 402 is a second coil unit, 403 is a third coil unit, 404 is a fourth coil unit, 405 is a left ear coil unit, and 406 is a right ear coil unit. DETAILED DESCRIPTION

[0080] The present application is further described in detail below through specific implementations in combination with the accompanying drawings. The present application can be implemented in a variety of different forms and is not limited to the implementation described in this embodiment. The purpose of providing the following specific implementations is to facilitate a clearer and more thorough understanding of the disclosure of the present application, wherein words indicating directions such as up, down, left, and right are only for the position of the structure shown in the corresponding drawings.

[0081] However, those skilled in the art may realize that one or more of the specific details may be omitted, or other methods, components or materials may be used. In some examples, some embodiments are not described or are not described in detail.

[0082] In addition, the technical features and technical solutions described herein may be combined in any suitable manner in one or more embodiments. It is easy for a person skilled in the art to understand that the steps or operation sequence of the methods related to the embodiments provided herein may also be changed. Therefore, any sequence in the drawings and embodiments is only for illustrative purposes and does not imply a requirement to follow a certain sequence unless it is explicitly stated that a certain sequence is required.

[0083] The serial numbers of the components in this document, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0084] Embodiment 1:

[0085] Figures 1 to 11 A preferred embodiment of the helmet-type primate experimental radio frequency coil device of the present application is shown, which is mainly composed of an animal fixing seat 1, four universal connecting rods 2, a coil support shell 3, a radio frequency receiving coil 4 and a signal wire 5, wherein:

[0086] The animal holder 1 is used to fix the animal to be tested, usually a monkey.

[0087] The coil support shell 3 is a helmet-type structure adapted to the head of a primate, and has a head receiving cavity for accommodating the head of the animal under test, and can be worn on the head of the animal under test to obtain a brain image of the animal under test with the aid of the radio frequency receiving coil 4 therein. The coil support shell 3 is mainly used to support and protect the radio frequency receiving coil 4 therein.

[0088] The radio frequency receiving coil 4 is fixed inside the coil supporting shell 3 and is a core component of magnetic resonance imaging.

[0089] The four universal connecting rods 2 are used to connect the aforementioned animal holder 1 and the coil support shell 3, so that the coil support shell 3 with the radio frequency receiving coil 4 inside can be used in conjunction with the animal holder 1, and the coil support shell 3 can also assist the animal holder 1 in strengthening the fixing effect on the animal's head. After the animal under test is fixed to the animal holder 1, the experimenter can bend each universal connecting rod 2 to adjust the angle of the coil support shell 3, so that the coil support shell 3 fits the animal's head very well, and then the radio frequency receiving coil 4 in the coil support shell 3 is as close to the animal's scalp as possible, thereby improving the signal-to-noise ratio of signal induction reception and obtaining a clearer magnetic resonance image.

[0090] The signal wire 5 is connected to the RF receiving coil 4 circuit and is led out of the coil support shell 3. When in use, the lead end of the signal wire 5 is connected to the magnetic resonance main device to transmit signals between the magnetic resonance main device and the coil device.

[0091] In this embodiment, the terms “front, back, left, and right” are used in the same manner unless otherwise specified. Figure 2 For reference, in Figure 2 In the figure, perpendicular to the paper plane and outward is the front, perpendicular to the paper plane and inward is the back, parallel to the paper plane and to the left is the right, and parallel to the paper plane and to the right is the left, which corresponds to the body position of the animal being tested.

[0092] The animal holder 1 mainly includes a support plate 101, two baffles 102, two ear bars 103, two guide rods and four rod clamps 105. Among them:

[0093] The supporting plate 101 is arranged at a small angle and is used to support the body of the animal being tested.

[0094] The two baffles 102 are respectively fixed to the left and right sides of the animal body supporting plate, and the two baffles 102 are arranged substantially vertically.

[0095] Two ear bars 103 are respectively installed on the left and right baffles, and the length of each ear bar is horizontally extended from left to right. The left and right positions of the ear bars on the baffles are adjustable. Specifically, the baffle 102 is provided with ear bar insertion holes that pass through the left and right sides and screw holes that are vertically connected to the ear bar insertion holes. The ear bars can be movably inserted into the ear bar insertion holes. After adjusting the left and right positions of the ear bars 103, the locking screws 106 are locked into the screw holes and squeezed on the ear bars, thereby fixing the ear bars. In actual application, the two ear bars are respectively pressed against the ears of the animal being tested to fix the position of the animal's head.

[0096] The two guide rods 104 are respectively fixed to the tops of the left and right baffles, and the length of each guide rod 104 is perpendicular to the ear bar and extends horizontally from front to back.

[0097] There are four rod clamps 105, two of which are connected to the left guide rod 104 in a front-to-back manner, and the other two rod clamps 105 are connected to the right guide rod 104 in a front-to-back manner, and the fixed position of each rod clamp 105 on the guide rod can be adjusted forward and backward. The aforementioned four universal connecting rods 2 are respectively connected to the four rod clamps 105, so that when in use, the connection position of the universal connecting rod 2 and the animal fixing seat 1 can be adjusted by changing the front-to-back position of the rod clamp 105 on the guide rod 104, so that the relative position of the coil support shell 3 and the animal fixing seat 1 can be adjusted in a wide range to better adapt to the head position of the animal being tested.

[0098] Reference Figure 1 and Figure 2 As shown, the above four universal connecting rods 2 are all made of plastic, two of which adopt the first structure, and the other two adopt the second structure, and the two universal connecting rods 2 of the first structure are in front of the two universal connecting rods 2 of the second structure. That is, the two rod clamps 105 on the same guide rod 104 are respectively connected to the universal connecting rods 2 of two different structures, and the universal connecting rod 2 connected by the front rod clamp 105 adopts the first structure, while the universal connecting rod 2 connected by the rear rod clamp adopts the second structure.

[0099] The first structure of the universal connecting rod 2 is composed of a first ball head tube 201, a second ball head tube 202, and a first ball socket tube 203 connecting the first ball head tube and the second ball head tube. The first ball head tube 201, the first ball socket tube 203 and the second ball head tube 202 are three rod sections of the universal connecting rod 2. Specifically:

[0100] The first ball head tube 201 is composed of a first tube body 201a and a first hollow ball head 201b integrally formed at one end of the first tube body. Figure 8 The right end of the rod clamp 105 is fastened and connected with the rod clamp 105 by the first screw 6. The second ball head tube 202 is composed of a second tube body and a second hollow ball head integrally formed at one end of the second tube body, and the other end of the second tube body is fastened and connected with the coil support shell 3 by the second screw. The first ball socket tube 203 is composed of a third tube body and two first ball sockets respectively formed at the two ends of the third tube body, and the first hollow ball head and the second hollow ball head 201b are respectively inserted into the two first ball sockets.

[0101] The universal connecting rod 2 is made of plastic, and the hollow ball head and ball socket on it will produce plastic deformation under the action of external force, so the hollow ball head can be squeezed into the ball socket manually or with the help of tools to complete the assembly of the universal connecting rod 2. After the assembly is completed, the hollow ball head and the ball socket are interference fit (that is, the two are tightly matched), and the relative position of the two is fixed in the natural state. When the user applies a sufficiently large force to the hollow ball head or the ball socket, the two will move relative to each other - the hollow ball head rotates in the ball socket, thereby changing the connection angle of each rod segment of the universal connecting rod.

[0102] Compared with a solid ball head, a hollow ball head has a stronger plastic deformation ability, which makes it easier to assemble the universal connecting rod. In addition, the hollow ball head uses less material, which reduces the material cost. At the same time, the hollow ball head has a small weight, which reduces the possibility of the universal connecting rod bending and deforming due to the weight of the ball head.

[0103] As described above, the other end of the first tube ( Figure 8 The right end of the second tube body is fastened to the rod clamp 105 by a first screw 6, and the other end of the second tube body is fastened to the coil support shell 3 by a second screw. The following will introduce this fastening connection method in detail:

[0104] The first ball head tube 201 is provided with a first through hole with two ends respectively located at the first tube body 201a and the first hollow ball head 201b. The first through hole is also the tube hole of the first ball head tube. Figure 8 The rod clamp 105 has a first annular inner flange 201a-1 which is located at the opening of one end of the first through hole and convex radially inward, and the surface of the rod clamp 105 is integrally provided with a first positioning groove 105a which is recessed inward. The other end of the first tube body 201a is embedded in the first positioning groove 105a, and the screw of the first screw 6 is locked into the rod clamp 105. The first annular inner flange 201a-1 is pressed and fixed between the screw head of the first screw 6 and the rod clamp 105.

[0105] A second through hole is provided in the second ball head tube 202, with two end openings respectively located at the second tube body and the second hollow ball head; the other end of the second tube body is integrally provided with a second annular inner flange located at the opening of one end of the second through hole and convex radially inward; a second positioning groove 302a recessed inwardly is integrally provided on the surface of the coil support shell 3; the other end of the second tube body is embedded in the second positioning groove 302a; the screw of the second screw is locked into the coil support shell 3; the second annular inner flange is pressed and fixed between the screw head of the second screw and the coil support shell.

[0106] The first screw 6 and the second screw are both large-head screws, that is, the radial dimension of the screw head portion is much larger than the radial dimension of the screw shaft portion.

[0107] The coil support shell 3 is composed of an inner shell wall 301 and an outer shell wall 302 that are detachably connected, and the radio frequency receiving coil 4 is arranged between the inner shell wall and the outer shell wall, so that the radio frequency receiving coil can be easily installed in the coil support shell 3. In addition, the detachable connection between the inner shell wall 301 and the outer shell wall 302 is achieved by the second screw mentioned above - the second screw is locked into the inner shell wall and the inner shell wall along the thickness direction of the coil support shell to lock and fix the outer shell wall and the inner shell wall. The advantages of such a design are:

[0108] 1. The same screw is responsible for connecting the universal connecting rod and the coil support shell, and is also responsible for connecting the inner and outer shell walls of the coil support shell, saving the number of parts and costs.

[0109] 2. Only when the universal connecting rod, especially the second ball head tube of the universal connecting rod, is connected with the coil support shell, the inner and outer shell walls will be fixed together to form a complete coil support shell. Therefore, the second ball head tube must be connected to the coil support shell under normal conditions to prevent people from removing the universal connecting rod to maintain the exclusivity of the coil device.

[0110] The second positioning groove 302 a is specifically formed on the surface of the housing wall 302 .

[0111] An outlet protection tube 302b is integrally provided on the housing wall 302, and the signal wire 5 is led out from the outlet protection tube 302b, and the outlet protection tube 302b is located in the middle of the four connection points between the four universal connecting rods and the coil support shell. In addition, the extended outlet protection tube 302b has a handle function, which can be held and carried by the user.

[0112] The second structure of the universal connecting rod 2 comprises five rod sections, namely, a third ball head tube 204, a second ball socket tube 205, a first ball head and socket tube 206, a second ball head and socket tube 207 and a fourth ball head tube 208, which are sequentially arranged and connected to each other along the length direction of the universal connecting rod. Among them:

[0113] The third ball head tube 204 is composed of a fourth tube body and a third hollow ball head integrally formed at one end of the fourth tube body, and the other end of the fourth tube body is fixedly connected to the rod clamp 105 by a third screw. The second ball socket tube 205 is composed of a fifth tube body and two second ball sockets respectively formed at both ends of the fifth tube body. The first ball head socket tube 206 is composed of a sixth tube body, a third ball socket integrally formed at one end of the sixth tube body, and a fourth hollow ball head integrally formed at the other end of the sixth tube body. The third hollow ball head and the fourth hollow ball head are respectively inserted in the two second ball sockets. The second ball head socket tube 207 is composed of a seventh tube body, a fourth ball socket integrally formed at one end of the seventh tube body, and a fifth hollow ball head integrally formed at the other end of the seventh tube body, and the fifth hollow ball head is inserted in the third ball socket. The fourth ball head tube 208 is composed of an eighth tube body and a sixth hollow ball head integrally formed at one end of the eighth tube body, the sixth hollow ball head is interference fit in the fourth ball socket, and the other end of the eighth tube body is fixedly connected to the coil support shell 3 by a fourth screw. The aforementioned eighth tube body is a right-angle structure, which is composed of a first tube segment and a second tube segment arranged vertically.

[0114] The connection mode between the fourth tube and the rod clamp 105 is the same as the connection mode between the first tube and the rod clamp 105, and the connection mode between the eighth tube and the coil support shell 3 is the same as the connection mode between the second tube and the coil support shell 3. The fourth screw used to connect the eighth tube and the coil support shell 3 is also responsible for connecting the inner and outer shell walls of the coil support shell.

[0115] After a lot of experiments, we found that the imaging quality of the monkey's head is the highest when the radio frequency receiving coil 4 adopts the following structure:

[0116] The radio frequency receiving coil 4 is composed of 16 coil units in total, of which two coil units are arranged at a large distance from left to right, namely the left ear coil unit 405 and the right ear coil unit 406, and the other 14 coil units are arranged between the left ear coil unit and the right ear coil unit. The aforementioned "other 14 coil units" are divided into four groups, namely the first coil unit group, the second coil unit group, the third coil unit group and the fourth coil unit group, and the first coil unit group, the second coil unit group, the third coil unit group and the fourth coil unit group are arranged in sequence from front to back. Among them: the first coil unit group is composed of four first coil units 401 arranged in sequence from left to right, the second coil unit group is composed of three second coil units 402 arranged in sequence from left to right (that is, any two adjacent second coil units are arranged in sequence), the third coil unit group is composed of four third coil units 403 arranged in sequence from left to right, and the fourth coil unit group is composed of three fourth coil units 404 arranged in sequence from left to right. Each second coil unit 402 is arranged to overlap partially with the corresponding two adjacent first coil units 401 and the corresponding two adjacent third coil units 403. The two fourth coil units 404 at the left and right ends of the fourth coil unit group are arranged to overlap partially with the two third coil units 403 at the left and right ends of the third coil unit group. The left ear coil unit 405 overlaps partially with the first coil unit 401 at the left end of the first coil group and the third coil unit 403 at the left end of the third coil group. The right ear coil unit 406 overlaps partially with the first coil unit 401 at the right end of the first coil group and the third coil unit 403 at the right end of the third coil group.

[0117] Each of the first coil unit 401 , the second coil unit 402 , the third coil unit 403 and the fourth coil unit 404 is a toroidal coil, and the left ear coil unit 405 and the right ear coil unit 406 are saddle coils.

[0118] It is not difficult to see that among the 14 coil units in the middle, there are many three coil units arranged in pairs, that is, any two of the three coil units are partially overlapped. In this embodiment, these three coil units arranged in pairs have no common overlapping area. Furthermore, any three coil units arranged in pairs have the same intersection point in the top view direction (only in the top view, the three coil units intersect at the same point, but in fact, the three coil units are insulated from each other), for example Figure 3 The two third coil units in the middle of the third coil unit group and the fourth coil unit in the middle of the fourth coil group.

[0119] When conducting the experiment, the standard experimental operation process is to first fix the anesthetized animal to be tested (primate, generally a monkey) on the animal fixing frame 1, then wear the coil support shell 3 with the above-mentioned radio frequency receiving coil 4 inside on the animal's head, and then perform a magnetic resonance imaging examination. However, when the head of the animal to be tested is fixed, the ear bars 103 on both sides are against the ears of the animal. Blocked by the ear bars 103, the above-mentioned left ear coil unit 405 and the right ear coil unit 406 cannot be closely mounted on the outer periphery of the ear of the animal to be tested, that is, the experimenter cannot wear the coil support shell on the animal's head unless the two ear coil units on both sides of the radio frequency receiving coil 4 are removed. However, we found that if the two ear coil units on both sides of the radio frequency receiving coil 4 are removed, it will have a greater negative impact on the imaging quality and imaging range.

[0120] Fortunately, we have solved the above problem very cleverly: Figures 4 to 6 As shown, the left ear coil unit 405 and the right ear coil unit 406 are respectively composed of a detachable upper half circle 40561 and a lower half circle 40562, wherein the upper half circle 40561 is always completely fixed inside the coil support shell 3, and the surface of the coil support shell 3 is provided with an inwardly extending plug hole 304, and the lower half circle 40562 is arranged in a long strip of protective shell 7. During the experiment, after the animal to be tested is fixed, the lower half circle 40562 of the ear coil unit has not been installed yet, so the coil support shell 3 can be smoothly worn on the animal's head, and then the two ends of the protective shell 7 are respectively aligned with the two plug holes 304 at the bottom of the coil support shell 3 and inserted upward, and the two ends of the lower half circle 40562 in the protective shell 7 are connected to the two ends of the upper half circle 40561 in the coil support shell 3 to form a complete ear coil unit. At this time, an ear clearance hole 8 is formed between the protective shell 7 and the coil support shell 3, which is sleeved on the outer periphery of the ear of the animal to be tested, and the ear coil unit is just arranged around the outer periphery of the ear clearance hole 8.

[0121] In this embodiment, the two ends of the lower half circle 40562 and the two ends of the upper half circle 40561 are connected to each other in the following manner: a conductive block connected to the end of the lower half circle 40562 is provided at the end of the protective shell 7, and a conductive spring connected to the end of the upper half circle 40561 is provided in the plug hole 304. After assembly, the conductive block and the conductive spring are elastically abutted against each other, that is, the lower half circle 40562 and the upper half circle 40561 are indirectly connected by means of the conductive block and the conductive spring abutting against each other.

[0122] If the protective shell 7 and the coil support shell 3 are fixed only by the elastic clamping force of the conductive spring and the conductive block, the protective shell 7 may fall off if not carefully during the experiment. In this regard, we fixedly installed a flexible rubber ring in the plug hole 304. When the end of the protective shell 7 is inserted into the plug hole 304, the end of the protective shell 7 is surrounded by the rubber ring and elastically clamped by the rubber ring.

[0123] If the protective shell 7 is made of a hard plastic material that cannot be deformed, it is necessary to ensure that the protective shell 7 has a very high manufacturing accuracy to minimize the assembly tolerance between the two ends of the protective shell 7 and the plug-in holes on the coil support shell 3, otherwise the protective shell 7 will be difficult or impossible to assemble onto the coil support shell 3. In addition, the hard protective shell 7 must also have a sufficiently large thickness, otherwise the elongated protective shell 7 will easily break when subjected to force. In this regard, the present embodiment uses a flexible material that can be bent at will to make the aforementioned protective shell 7, so that the angle and position of the end of the protective shell 7 can be adjusted at will during assembly to match the position and angle of the plug-in hole 304 on the coil support shell 3, and the two protective shells 7 on the left and right sides can be replaced at will. Moreover, the protective shell 7 made of a flexible material can be perfectly placed against the ears of each animal being tested to improve imaging quality.

[0124] The above-mentioned flexible material can be rubber or insulating DuPont cloth and the like.

[0125] In order to be able to acquire images or data of other imaging methods while acquiring magnetic resonance images, the present embodiment has four test holes 303 for inserting data acquisition equipment through the coil support shell 3. When performing magnetic resonance imaging on an animal, the required probe or electrode can be inserted through the test hole 303 and attached to the surface of the animal's scalp or inserted into the cerebral cortex to acquire images or data of other imaging methods, thereby realizing multimodal imaging.

[0126] A coil unit (one of the 14 coil units in the middle) is arranged around each of the test holes 303. In this way, during imaging detection, the RF receiving coil 4 in the coil support shell 3 will be closer to the animal's scalp, thereby improving the signal-to-noise ratio of signal induction reception and improving the quality of magnetic resonance imaging. This is because:

[0127] 1. After the coil support shell 3 is opened, the opening will not block the animal's head, and will not be blocked by the exposed part of the fixing device implanted in the animal's head, so that the inner wall surface of the coil support shell 3 can be closer to the animal's scalp.

[0128] 2. The head of the animal is roughly spherical, and the head area at the test hole 303 will extend into the test hole 303 and the coil unit outside the test hole 303.

[0129] In addition, during the process of magnetic resonance imaging, a safety factor that cannot be ignored is the thermal effect of the radio frequency field. Although magnetic resonance examination does not use X-rays, it is necessary to emit radio frequency pulses to excite hydrogen protons in the body. The tissue absorbs the energy of the radio frequency, which may cause the temperature of the tissue to rise, and generate heating or heat accumulation effects locally. The accumulation of heat is generally represented by the radio frequency specific absorption rate (SAR) SAR value. The larger the SAR value, the higher the heat accumulated by the radio frequency may be, the more obvious the feeling of tissue heating is, and the greater the increase in local tissue temperature. During the scanning process, especially some magnetic resonance pulse sequences with high SAR values, it may bring excessive thermal effects to the animal's head tissue. In this case, the magnetic resonance image collected is not the magnetic resonance image at the actual body temperature of the animal. However, the rigor of scientific research requires that the experimenter should ensure that the head temperature of the animal is as close to the normal body temperature as possible when performing imaging tests on the animal. The detection hole 303 opened on the coil support shell 3 in this embodiment increases the gas permeability between the imaging tissue and the external environment, which can dissipate the generated heat in time, prevent local overheating or hypoxia, avoid damage to body tissues, and improve the accuracy of the detection data.

[0130] In addition, during the magnetic resonance imaging experiment, with the help of the detection hole 303 opened on the coil, the experimenter can better observe and adjust the distance between the coil and the head of the subject animal, make further flexible positioning and stability reinforcement, and increase the freedom of mechanical fixation of the coil.

[0131] When conducting a magnetic resonance imaging experiment, each coil unit of the radio frequency receiving coil 4 will generate heat due to the flow of current. As mentioned above, the detection hole is conducive to the dissipation of heat to prevent local overheating or hypoxia. In addition, a part of the head of the animal under test will extend into the test hole so that the coil unit at the hole is closer to the animal's scalp. Based on this, the present embodiment arranges the coil unit at the hole against the outer surface of the inner shell wall 301 of the coil support shell 3 and the outer surface of the hole wall of the detection hole 303. With such a design, the heat emitted by the coil unit at the hole can be more quickly absorbed and carried away by the airflow in the hole, and at the same time, the extension amount of the head of the animal under test to the coil unit is further increased, further improving the signal-to-noise ratio of the signal induction reception. The detection hole 303 obviously has a cylindrical hole wall formed by the inner and outer walls of the coil support shell. The so-called "outer surface of the hole wall of the detection hole" refers to the outer peripheral surface of the aforementioned cylindrical hole wall.

[0132] Moreover, all 16 coil units (the upper half of the ear coil) of the radio frequency receiving coil are arranged close to the outer surface of the inner wall of the coil support shell, so that the coil unit is closer to the animal's scalp.

[0133] Embodiment 2:

[0134] Fig.12 and Fig.13 Another specific embodiment of the helmet-type primate experimental radio frequency coil device of the present application is shown. The structure of the coil device is basically the same as that of the coil device in the first embodiment, and the main difference is that:

[0135] The radio frequency receiving coil 4 in the coil support shell 3 is composed of only 6 coil units. Because the imaging quality of these 6 coil units is worse than that of the radio frequency receiving coil with 16 coil units in the first embodiment, and the distribution of these 6 coil units is not particularly bright compared with the first embodiment, it will not be described in detail here.

[0136] Only two rod clamps 105 are provided, which are respectively connected to two guide rods 101. Correspondingly, only two universal connecting rods 4 are provided.

[0137] Of course, the above embodiments are only for illustrating the technical concept and features of the present application, and their purpose is to enable people to understand the content of the present application and implement it accordingly, and they cannot be used to limit the protection scope of the present application. Any equivalent transformation or modification made according to the spirit of the main technical solution of the present application should be included in the protection scope of the present application.

Claims

1. A high-fitting helmet-type primate magnetic resonance experiment radio frequency coil device, characterized in that: include: An animal holder (1) for fixing the animal to be tested, A helmet-shaped coil support shell (3) connected to the animal fixing seat via a universal connecting rod (2) and capable of being worn on the head of the animal being tested, a radio frequency receiving coil (4) arranged in the coil supporting shell (3), and A signal wire (5) connected to the radio frequency receiving coil (4) circuit and extending outside the coil supporting shell (3); The animal fixing seat (1) comprises: A support plate (101) for supporting the body of an animal, two baffles (102) respectively fixed to the left and right sides of the animal body supporting plate, and Two ear bars (103) respectively mounted on the two baffles and extending horizontally from left to right; The two ear bars (103) are used to respectively press against the ears of the animal being tested; The radio frequency receiving coil (4) comprises a left ear coil unit (405) and a right ear coil unit (406) which are respectively arranged close to the periphery of the ears of the animal being tested, and the left ear coil unit (405) and the right ear coil unit (406) are respectively composed of an upper half circle (40561) and a lower half circle (40562) which are detachably connected.

2. The high-fitting helmet-type primate magnetic resonance experiment radio frequency coil device according to claim 1, characterized in that: The animal fixing seat (1) comprises: two guide rods (104) respectively fixed to the tops of the two baffles and extending horizontally frontward and rearward perpendicular to the ear bars, and At least two rod clamps (105) are respectively connected to the two guide rods and the fixed positions on the guide rods are adjustable forward and backward; A universal connecting rod (2) is connected between each of the rod clamps (105) and the coil support shell (3).

3. The high-fitting helmet-type primate magnetic resonance experiment radio frequency coil device according to claim 2, characterized in that: The universal connecting rod (2) is made of plastic material. Each guide rod (104) is connected to two rod clamps (105) distributed front and back. The universal connecting rod (2) connected to the front rod clamp (105) includes: A first ball head tube (201), which is composed of a first tube body (201a) and a first hollow ball head (201b) integrally formed at one end of the first tube body, and the other end of the first tube body is fastened to the rod clamp (105) by a first screw (6); A second ball head tube (202), which is composed of a second tube body and a second hollow ball head integrally formed at one end of the second tube body, and the other end of the second tube body is fastened to the coil support shell (3) by a second screw; and The first ball socket tube (203) is composed of a third tube body and two first ball sockets respectively formed at two ends of the third tube body, and the first hollow ball head and the second hollow ball head are respectively interference-embedded in the two first ball sockets.

4. The high-fitting helmet-type primate magnetic resonance experiment radio frequency coil device according to claim 3, characterized in that: A first through hole is provided through the first ball head tube (201), and the openings at both ends are located at the first tube body (201a) and the first hollow ball head (201b) respectively; the other end of the first tube body (201a) is integrally provided with a first annular inner flange (201a-1) which is located at the opening of one end of the first through hole and is radially convex inward; the surface of the rod clamp (105) is integrally provided with a first positioning groove (105a) which is recessed inward; the other end of the first tube body (201a) is embedded in the first positioning groove (105a); the screw rod of the first screw (6) is locked into the rod clamp (105); and the first annular inner flange (201a-1) is pressed and fixed between the screw head of the first screw (6) and the rod clamp (105); A second through hole is provided in the second ball head tube, and the openings at both ends are respectively located at the second tube body and the second hollow ball head; the other end of the second tube body is integrally provided with a second annular inner flange which is located at the opening at one end of the second through hole and is radially convex inward; the surface of the coil support shell (3) is integrally provided with a second positioning groove (302a) which is recessed inward; the other end of the second tube body is embedded in the second positioning groove (302a); the screw rod of the second screw is locked into the coil support shell (3); and the second annular inner flange is pressed and fixed between the screw head of the second screw and the coil support shell (3).

5. The high-fitting helmet-type primate magnetic resonance experiment radio frequency coil device according to claim 4, characterized in that: The coil support shell (3) comprises an inner shell wall (301) and an outer shell wall (302) that are detachably connected, the radio frequency receiving coil (4) is arranged between the inner shell wall and the outer shell wall, and the second screw locks and fixes the inner shell wall and the outer shell wall.

6. The high-fitting helmet-type primate magnetic resonance experiment radio frequency coil device according to claim 5, characterized in that: An outlet wire protection tube (302b) is integrally provided on the shell wall (302), and the signal wire (5) is led out from the outlet wire protection tube (302b).

7. The high-fitting helmet-type primate magnetic resonance experiment radio frequency coil device according to claim 2, characterized in that: The universal connecting rod (2) connected to the rear rod clamp (105) comprises: A third ball head tube (204), which is composed of a fourth tube body and a third hollow ball head integrally formed at one end of the fourth tube body, and the other end of the fourth tube body is fixedly connected to the rod clamp (105); A second ball-and-socket tube (205), which is composed of a fifth tube body and two second ball-and-socket tubes respectively formed at two ends of the fifth tube body; A first ball head and socket tube (206), which is composed of a sixth tube body, a third socket integrally formed at one end of the sixth tube body, and a fourth hollow ball head integrally formed at the other end of the sixth tube body, wherein the third hollow ball head and the fourth hollow ball head are respectively interference-embedded in the two second sockets; A second ball head and socket tube (207), which is composed of a seventh tube body, a fourth socket integrally formed at one end of the seventh tube body, and a fifth hollow ball head integrally formed at the other end of the seventh tube body, wherein the fifth hollow ball head is interference fit in the third socket; and a fourth ball head tube (208), which is composed of an eighth tube body and a sixth hollow ball head integrally formed at one end of the eighth tube body, the sixth hollow ball head being interference fit in the fourth ball socket, and the other end of the eighth tube body being fixedly connected to the coil support shell (3); The eighth tube body is a right-angle structure, which is composed of a first tube segment and a second tube segment arranged vertically.

8. The high-fitting helmet-type primate magnetic resonance experiment radio frequency coil device according to claim 1, characterized in that: The radio frequency receiving coil (4) comprises: The left ear coil unit (405), a right ear coil unit (406), and The first coil unit group, the second coil unit group, the third coil unit group and the fourth coil unit group are arranged between the left ear coil unit and the right ear coil unit and arranged in sequence from front to back; The first coil unit group is composed of four first coil units (401) arranged in sequence from left to right with intervals, the second coil unit group is composed of three second coil units (402) arranged in sequence from left to right with partial overlaps, the third coil unit group is composed of four third coil units (403) arranged in sequence from left to right with partial overlaps, and the fourth coil unit group is composed of three fourth coil units (404) arranged in sequence from left to right with partial overlaps; Each of the second coil units (402) is arranged to partially overlap with corresponding two adjacent first coil units (401) and corresponding two adjacent third coil units (403); The two fourth coil units (404) at the left and right ends of the fourth coil unit group are respectively arranged to partially overlap with the two third coil units (403) at the left and right ends of the third coil unit group; The left ear coil unit (405) is arranged to partially overlap with the first coil unit (401) at the left end of the first coil unit group and the third coil unit (403) at the left end of the third coil unit group; The right ear coil unit (406) is arranged to partially overlap with the first coil unit (401) at the right end of the first coil unit group and the third coil unit (403) at the right end of the third coil unit group.

9. The high-fitting helmet-type primate magnetic resonance experiment radio frequency coil device according to claim 8, characterized in that: The first coil unit (401), the second coil unit (402), the third coil unit (403) and the fourth coil unit (404) are all annular coils, and the left ear coil unit (405) and the right ear coil unit (406) are both saddle coils.

10. The high-fitting helmet-type primate magnetic resonance experiment radio frequency coil device according to claim 8, characterized in that: Any two or more of the three coil units that are partially overlapped have no common overlapping area.

Images