Magnetically compatible rodent brain injection device and method

Abstract

The invention belongs to the technical field of magnetic resonance imaging, and particularly discloses a magnetic compatible rodent brain injection device and method.The magnetic compatible rodent brain injection device comprises a fixed base, an injection catheter system and a medicine conveying system, and the bottom face of the fixed base is fixedly connected with the surface of a skull through an adhesive; a three-dimensional positioning fine-tuning system is arranged on the top surface of the fixed base, the three-dimensional positioning fine-tuning system is fixedly connected with an outer ring of the injection catheter system, and one end of the injection catheter system sequentially penetrates through the three-dimensional positioning fine-tuning system and the fixed base and is communicated with the interior of the skull; and the other end of the injection catheter system is communicated with the medicine conveying system. According to the magnetic compatible rodent brain injection device and method, signal artifacts or interference is avoided, imaging compatibility and operation convenience are achieved, intracerebral medicine injection which is high in precision, good in repeatability and small in brain tissue damage is achieved, and a reliable technical means is provided for brain research.

Description

Technical Field

[0001] The present invention relates to the field of magnetic resonance imaging technology, and in particular to a magnetically compatible rodent brain injection device and method. Background Art

[0002] Magnetic resonance imaging (MRI) is a non-invasive medical imaging technology that can provide high-resolution images of the internal structure of tissues, especially in soft tissue imaging. MRI technology is increasingly used in the field of neuroimaging. It can non-invasively observe the changes in brain tissue structure and function under physiological and pathological conditions, and accurately locate specific brain regions. In the study of brain disease models, rodents are often used as experimental subjects for imaging studies, and drug injection into the brain parenchyma or ventricular region is often an indispensable part.

[0003] In the prior art, traditional drug delivery devices are usually made of stainless steel. These devices are suitable for chronic drug delivery outside MRI, but they have limitations when used in a nuclear magnetic resonance scanning environment, especially in the process of acute modeling or acute drug delivery. Traditional stainless steel drug delivery sleeves cannot be used normally under MRI scanning, and real-time image scanning before and after drug delivery cannot be achieved. In addition, traditional drug delivery sleeves have many limitations. The injection depth needs to be customized and is difficult to adjust flexibly; the positioning catheter needs to penetrate deep into the animal's brain, and the larger outer diameter can easily cause craniocerebral injury; in addition, the catheter base is thick, so that the surface coil cannot fit tightly and wrap around the skull during MRI imaging, thus affecting the imaging quality.

[0004] Therefore, developing a rodent brain injection cannula device that can be used stably in a magnetic resonance environment can enable brain injection operations to be carried out smoothly during MRI scanning, thereby promoting the smooth development of related imaging research and experiments. Summary of the invention

[0005] The purpose of the present invention is to provide a magnetically compatible rodent brain injection device and method, which avoids signal artifacts or interference, has both imaging compatibility and ease of operation, realizes high-precision, good repeatability, and brain tissue-less damage to brain drug injection, successfully realizes liquid distribution monitoring and position calibration, and provides a reliable technical means for brain science, drug development and neurological disease research.

[0006] To achieve the above-mentioned purpose, the present invention provides a magnetically compatible rodent brain injection device, comprising a fixed base, an injection catheter system and a drug delivery system, wherein the bottom surface of the fixed base is fixedly connected to the surface of the skull by an adhesive, and the top surface of the fixed base is provided with a stereotaxic fine-tuning system, and the stereotaxic fine-tuning system is fixedly connected to the outer ring of the injection catheter system, one end of the injection catheter system sequentially passes through the stereotaxic fine-tuning system and the fixed base and is connected to the inside of the skull, and the other end of the injection catheter system is connected to the drug delivery system.

[0007] Preferably, the bottom surface of the fixed base is provided with a plurality of fixing notches, and the adhesive is made of one or both of dental cement and bone cement.

[0008] Preferably, the stereo positioning fine-tuning system includes a fine-tuning component and a fixed component, the fine-tuning component includes an X-axis track and a Y-axis track, the X-axis track and the Y-axis track are both provided with a threaded knob, the bottom surface of the X-axis track is slidably connected to the fixed base via the threaded knob, the bottom surface of the Y-axis track is slidably connected to the top surface of the X-axis track via the threaded knob, and the fixed component is arranged at the center position of the top surface of the Y-axis track.

[0009] Preferably, the injection catheter system includes a dosing sleeve and a positioning catheter sleeved on the outer wall of the dosing sleeve, one end of the positioning catheter is fixedly connected to the fixing assembly, the other end of the positioning catheter is provided with a fastening knob, the dosing sleeve is fixedly connected to the positioning catheter via the fastening knob, and the outer wall of the fastening knob is provided with anti-slip grooves.

[0010] Preferably, the outer diameter of the drug delivery sleeve is equal to the inner diameter of the positioning catheter, and the length of the drug delivery sleeve is greater than the length of the positioning catheter.

[0011] Preferably, the drug delivery sleeve is made of quartz, and the positioning catheter and the fastening knob are both made of non-metallic materials.

[0012] Preferably, the fixed base and the stereo positioning fine-tuning system are both made of non-metallic materials, specifically one of polyetheretherketone or Teflon.

[0013] Preferably, the drug delivery system comprises a PE tube, a microsyringe and a microsyringe pump, and the microsyringe adopts a threaded knob propulsion design.

[0014] On the other hand, the present invention also provides a magnetically compatible rodent brain injection method, using the above-mentioned magnetically compatible rodent brain injection device, comprising the following steps: S1. Fixation and positioning: Fix the animal on the stereotaxic instrument, ensure that the head surface is parallel to the horizontal plane of the stereotaxic instrument, open the animal's scalp, expose the skull, and drill a hole in the skull above the target area to a depth that reaches the surface of the dura mater; S2. Installation of the fixed base and positioning catheter: Bond the fixed base to the skull around the drill hole, install the positioning catheter after curing, lock it on the stereotaxic fine-tuning system, and adjust the XY direction to make the positioning catheter face the drill hole; S3. Preparation of dosing cannula: connect the dosing cannula pre-filled with a set dose of injection liquid to a PE tube pre-filled with physiological saline. The PE tube runs through the inside and outside of the nuclear magnetic resonance environment. The external PE tube is connected to the micro-syringe and fixed on the micro-syringe pump. S4, animal MRI scanning: transfer the animal obtained in S2 to the scanning workroom, fix it, monitor physiological indicators, and then insert the drug administration cannula obtained in S3 into the positioning catheter. After reaching the target depth, use the knob to fix the drug administration cannula and the positioning catheter; S5, checking whether the target area is accurately positioned by magnetic resonance structural imaging scanning, if the target area is not reached, repeating S4 until the positioning is accurate; S6. Drug injection: Start the microinjection pump to inject the set dose of injection liquid, saline and blood at the preset rate, and use MRI for imaging to check the distribution of the liquid in the brain; S7. Remove the drug delivery cannula: If subsequent experimental injections are required at the same location, install a protective cover to cover the positioning catheter at the drilling location. If no subsequent experiments are to be performed, remove the positioning catheter and seal the wound.

[0015] Preferably, S6 further comprises the following steps: Start the microinjection pump, and first inject the deep nuclei at a preset rate and a set dose of liquid. Let it stand, then use MRI for imaging, and then adjust the depth of the dosing cannula upwards, and then fix it with the tightening knob, and inject the set dose of liquid into the cortex to check the distribution of the liquid in the brain.

[0016] Therefore, the present invention adopts the above-mentioned magnetically compatible rodent brain injection device and method, and the beneficial effects are as follows: (1) Strong magnetic compatibility: The device of the present invention uses non-magnetic materials and can work stably in the strong magnetic field environment of MRI without being disturbed by the magnetic field, thus ensuring the image quality during MRI imaging and the accuracy of drug injection operation. The injection operation and MRI imaging can be performed simultaneously, thereby improving the efficiency and accuracy of the experiment.

[0017] (2) Precise positioning: The present invention uses a high-precision stereo positioning fine-tuning device in conjunction with a positioning catheter, so that the drug administration cannula can be accurately aligned with the predetermined hole on the skull of the experimental animal, ensuring that the drug is accurately injected into the target brain area, avoiding drug leakage or misinjection, thereby reducing errors in the drug injection process. The positioning catheter does not need to penetrate deep into the brain, thereby reducing damage to brain tissue.

[0018] (3) High safety: The device of the present invention can minimize the harm to experimental animals. The drug administration sleeve is made of glass material and is fixed to the positioning catheter by a tightening knob to ensure its stability during the injection process. After the injection, the drug administration sleeve can be safely removed without causing lasting harm to the animal. The protective cover can effectively protect the wound and avoid infection and damage.

[0019] (4) Real-time monitoring: The present invention can monitor the distribution and diffusion of drugs in the brain in real time through MRI equipment, allowing researchers to accurately observe the effects of drugs.

[0020] (5) The device of the present invention has a compact structure and is easy to operate. It can quickly complete drug injection during the experiment and observe the response of brain tissue in real time under MRI scanning. It can be applied to the research of various experimental animal models and is suitable for various experimental scenarios such as acute drug administration and drug delivery evaluation. It is particularly suitable for the establishment of acute brain disease models and drug treatment research, and is easy to promote and use.

[0021] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of an embodiment of a magnetically compatible rodent brain injection device of the present invention; Figure 2 is an exploded schematic diagram of an embodiment of a magnetically compatible rodent brain injection device of the present invention; Figure 3 The MRI scans of an embodiment of a magnetically compatible rodent brain injection method of the present invention, wherein (a) is before liquid injection, and (b) is after liquid injection.

[0023] Reference numerals 1. Fixed base; 2. Fixed notch; 3. X-axis track; 4. Y-axis track; 5. Threaded knob; 6. Fixed assembly; 7. Drug delivery sleeve; 8. Positioning catheter; 9. Tightening knob; 10. Anti-slip pattern. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0025] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0026] Embodiment 1 like Figure 1 and Figure 2 As shown, a magnetically compatible rodent brain injection device includes a fixed base 1, a stereotaxic fine-tuning system, an injection catheter system and a drug delivery system (not marked in the figure). The fixed base 1 and the stereotaxic fine-tuning system are both made of non-metallic materials, specifically one of polyetheretherketone or Teflon, which is a magnetically compatible material and a high-performance biocompatible material to avoid MRI artifacts and signal interference. The bottom surface of the fixed base 1 is fixedly connected to the surface of the skull by an adhesive, and the adhesive is dental cement or bone cement. The bottom surface of the fixed base 1 is provided with a plurality of fixing notches 2, which cooperate with dental cement or bone cement to ensure that the device is firmly fixed on the animal skull, compatible with a stereotaxic instrument, and provide stable support.

[0027] The top surface of the fixed base 1 is provided with a stereo positioning fine-tuning system, and the stereo positioning fine-tuning system is fixedly connected to the outer ring of the injection catheter system. The stereo positioning fine-tuning system is used to accurately adjust the position of the injection catheter system to ensure that the injection catheter system is accurately docked with the pre-drilled hole on the skull. Specifically, the stereo positioning fine-tuning system includes a fine-tuning component and a fixed component 6, and the fine-tuning component includes an X-axis track 3 and a Y-axis track 4. The X-axis track 3 and the Y-axis track 4 are both provided with a threaded knob 5. The bottom surface of the X-axis track 3 is slidably connected to the fixed base 1 through the threaded knob 5, and the bottom surface of the Y-axis track 4 is slidably connected to the top surface of the X-axis track 3 through the threaded knob 5. The fixed component 6 is arranged at the center position of the top surface of the Y-axis track 4. The resolution of the threaded knob 5 reaches 0.1mm. After the fine-tuning is completed, the device can be locked and the position of the injection catheter system can be fixed to prevent errors caused by sliding of the device.

[0028] One end of the injection catheter system sequentially passes through the stereo positioning fine-tuning system and the fixed base 1 and is connected to the inside of the skull. Specifically, the injection catheter system includes a drug delivery sleeve 7 and a positioning catheter 8 sleeved on the outer wall of the drug delivery sleeve 7, one end of the positioning catheter 8 is fixedly connected to the fixing assembly 6, and the other end of the positioning catheter 8 is provided with a fastening knob 9, and the drug delivery sleeve 7 is fixedly connected to the positioning catheter 8 through the fastening knob 9, and the outer wall of the fastening knob 9 is provided with an anti-slip pattern 10, which is convenient for quickly adjusting the position between the drug delivery sleeve 7 and the positioning catheter 8, guiding the drug delivery sleeve 7 to accurately reach the target area, and reducing the risk of brain tissue damage. The outer diameter of the drug delivery sleeve 7 is equal to the inner diameter of the positioning catheter 8 to avoid the drug delivery sleeve 7 from swinging. The length of the drug delivery sleeve 7 is greater than the length of the positioning catheter 8, and the positioning catheter 8 has an appropriate length, which can provide a guiding effect for the drug delivery sleeve 7, and the drug delivery sleeve 7 can be fixed to it by the fastening knob 9, and the positioning catheter 8 is located above the skull to avoid direct contact with the brain, effectively avoiding damage to the brain tissue.

[0029] The overall design of the fixed base 1, the positioning catheter 8 and the drug delivery cannula 7 ensures the imaging effect, the accuracy of the injection site and the reliability of the experiment in the high-field MRI environment. The stereo positioning fine-tuning system and the tightening knob 9 ensure the precise adjustment and positioning function of the drug delivery cannula 7 in the three-dimensional directions of X, Y and Z, ensuring that the positioning catheter 8 and the drug delivery cannula 7 are accurately docked in the target area, achieving high-precision position adjustment.

[0030] The other end of the injection catheter system is connected to the drug delivery system. The drug delivery system includes a PE tube, a micro-syringe and a micro-syringe pump. The micro-syringe adopts a threaded knob propulsion design to guide the liquid in the drug delivery sleeve 7 to accurately reach the target area, ensuring that the injection range is controllable. The micro-syringe pump can accurately control the delivery rate and injection volume of the drug. The micro-syringe and micro-syringe pump can perform precise drug delivery control outside the magnetic resonance environment.

[0031] The drug delivery cannula 7 is made of quartz, and the positioning catheter 8 and the fastening knob 9 are all made of non-metallic materials. Taking advantage of the biocompatibility and corrosion resistance of the quartz material, the drug delivery cannula 7 is connected to the PE tube and filled with drugs or liquids to achieve high-precision drug delivery. The drug delivery cannula 7 has a certain length and hardness, which can effectively reach the target area. After the experiment, the drug delivery cannula 7 can be safely removed without causing lasting harm to the animal.

[0032] Embodiment 2 A magnetically compatible rodent brain injection method (single-step injection method) using the device of Example 1 was used for a mouse brain parenchyma drug injection experiment (mouse cerebral hemorrhage model autologous blood injection experiment) to verify the effectiveness and operability of the present invention for precise autologous blood injection in the mouse brain parenchyma area, and to evaluate its imaging compatibility in a high-field MRI environment.

[0033] Animal preparation: C57BL / 6 male mice were anesthetized with isoflurane inhalation anesthesia at a concentration of 1.2%-2.0%. The anesthesia depth was moderate to avoid death due to over-anesthesia or interference with the surgery due to insufficient anesthesia.

[0034] The specific steps are as follows: 1. Fixing and positioning The mouse was fixed in prone position on a small animal stereotaxic instrument, ensuring that the ear bars were firmly fixed and the head surface was parallel to the horizontal plane of the stereotaxic instrument. The mouse scalp was opened with surgical tools to expose the skull. A skull drill was used to drill a hole in the skull above the target area of ​​the right brain parenchyma, reaching the surface of the dura mater to avoid damaging the brain tissue. (The target area was the striatum, 0.8 mm in front of the anterior fontanelle, 2.2 mm on the right side, and 3.5 mm deep).

[0035] 2. Installation of the fixed base 1 and the positioning guide tube 8 ① Installation of the fixed base 1: Bond the fixed base 1 to the skull around the drill hole with bone cement or dental cement, and wait for solidification to ensure stability.

[0036] ② Installation of the positioning catheter 8: Install the positioning catheter 8 (outer diameter 0.4mm, inner diameter 0.25mm), lock it on the stereotaxic fine-tuning system, fine-tune the XY direction through the threaded knob to make the positioning catheter 8 face the drilled hole, and insert an optical fiber with an outer diameter of 0.25mm to confirm the alignment.

[0037] 3. Preparation of Drug Delivery Cannula 7 The quartz drug delivery sleeve 7 is connected to the PE10 tube, which runs through the inside and outside of the nuclear magnetic resonance (MRI) environment. The external PE10 tube is connected to the Hamilton micro-injector and fixed on the micro-injection pump. The PE10 tube is filled with physiological saline to prevent the injection volume error caused by the compression of the gas during the push injection. The drug delivery sleeve 7 is filled with the required dose of injection liquid in advance.

[0038] 4. Blood Collection from Mice Blood was collected from the mouse tail artery: After local disinfection, the end of the mouse tail was cut with a knife to collect the naturally flowing blood, and squeezed to prevent mixing with tissue fluid. The administration cannula 7 prepared just now was used to extract 1 μL of air from the external microsyringe to separate the saline and blood, and then 30 μL of blood was quickly extracted to prevent blood coagulation. After the extraction was completed, it was placed next to the MRI bed for use.

[0039] 5. Animal MRI Scanning The surgically treated mice were transferred to the nuclear magnetic resonance scanning room and imaged using a 9.4T small animal MRI scanner. Ear bars and tooth bars were used for fixation to reduce the movement of the head during scanning. In this embodiment, a mouse 3-channel phased surface array optogenetic coil was used so that there was an operable space on the top of the mouse head, and a drug delivery cannula 7 could be placed. After the coil was fixed, the physiological state of the mouse was monitored and recorded in real time by a rectal temperature and respiration detector, and the normal physiological indicators maintained by the water bed and anesthesia machine.

[0040] 6. Place the drug delivery cannula 7 The drug administration cannula 7 filled with 30 μL of blood and prepared in full is passed through the coil and inserted into the positioning catheter 8. Since the quartz material is hard enough, the drug administration cannula 7 can directly pass through the hole on the surface of the skull and pierce the dura mater and enter the brain. The downward depth is measured by a ruler, and the drug administration cannula 7 is slowly pushed deeper. After reaching the target depth, the drug administration cannula 7 and the positioning catheter 8 are fixed using the tightening knob 9. After preparation is completed, the mouse is subjected to magnetic resonance scanning imaging.

[0041] 7. Check whether the target area is accurately positioned through magnetic resonance imaging scanning Scan the T2-weighted structural image (TR / TE: 3000 / 33ms, Matrix: 200×200, FOV: 20×20mm2, averages: 2, slice thickness: 0.5mm, 31slices) to quickly locate the specific depth of the drug delivery cannula 7. The insertion depth of the drug delivery cannula 7 can be determined in real time through the magnetic resonance scanning image. If the target brain area is not reached, repeat the steps of placing the drug delivery cannula 7, adjust the depth of the drug delivery cannula 7, and then perform a quick scan to ensure the accuracy of the injection positioning.

[0042] 8. Drug injection After the drug delivery cannula 7 is adjusted to the target area (depth 3.5 mm) and confirmed to be correct, the mouse autologous blood is slowly injected at a rate of 2 μL / min (total injection volume 20 μL) using a microinjection pump at a preset time point according to the experimental protocol. After the injection is completed, MRI imaging is continued to be used to check the distribution of the fluid in the brain parenchyma and verify the accuracy of the injection position.

[0043] 9. Removal of the Injection Catheter System Since the drug delivery cannula 7 is only fixed to the positioning catheter 8, the drug delivery cannula 7 can be removed after the scanning experiment is completed. If a subsequent experimental injection is required at the same position, a protective cover can be installed to cover the positioning catheter 8 at the drilling position. The protective cover has sealing and repeated positioning functions, supporting safe operation and high repeatability in multiple injection experiments. If no subsequent experiments are to be performed, the positioning catheter 8 can be removed and the wound can be sealed to prevent infection.

[0044] Experimental results: like Figure 3 As shown, the magnetically compatible intraparenchymal injection device can accurately locate the target brain area (striatum), the MRI imaging is clear, and no artifacts or signal interference are observed, indicating that the device is fully compatible in a high-field MRI environment.

[0045] Embodiment 3 A magnetically compatible rodent brain injection method (two-step injection method) adopts the device of Example 1 and is used for a mouse brain parenchyma drug injection experiment (autologous blood injection scheme for mouse cerebral hemorrhage model).

[0046] The single-step injection method of the cerebral hemorrhage model may have defects such as unstable hematoma volume or blood reflux, so a two-step injection method can be further used to improve the success rate while reducing blood reflux.

[0047] Modeling method: After the drug administration cannula 7 reaches the target brain area through structural imaging scanning, 10 μL of autologous blood is injected first, and then left to stand for 7 minutes to form a blood clot to block the needle tract. During this period, enter the nuclear magnetic resonance scanning workshop to adjust the depth of the drug administration cannula 7, lift the drug administration cannula 7 upward by 2 mm and then use the tightening knob 9 to fix it. After completion, the remaining 10 μL of blood is injected, which can effectively reduce the amount of blood reflux from the needle tract and better control the size, shape and location of the hematoma.

[0048] Therefore, the present invention adopts the above-mentioned magnetically compatible rodent brain injection device and method to avoid signal artifacts or interference, combine imaging compatibility and ease of operation, achieve high-precision, good repeatability, and brain tissue-less damage to brain drug injection, successfully realize liquid distribution monitoring and position calibration, and provide a reliable technical means for brain science, drug development and neurological disease research.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A magnetically compatible rodent brain injection device, characterized in that: It includes a fixed base, an injection catheter system and a drug delivery system. The bottom surface of the fixed base is fixedly connected to the surface of the skull by adhesive. The top surface of the fixed base is provided with a stereo positioning fine-adjustment system. The stereo positioning fine-adjustment system is fixedly connected to the outer ring of the injection catheter system. One end of the injection catheter system passes through the stereo positioning fine-adjustment system and the fixed base in sequence and is connected to the inside of the skull. The other end of the injection catheter system is connected to the drug delivery system.

2. A magnetically compatible rodent brain injection device according to claim 1, characterized in that: The bottom surface of the fixed base is provided with a plurality of fixing notches, and the adhesive is one or both of dental cement and bone cement.

3. A magnetically compatible rodent brain injection device according to claim 1, characterized in that: The stereo positioning fine-tuning system includes a fine-tuning component and a fixed component, the fine-tuning component includes an X-axis track and a Y-axis track, the X-axis track and the Y-axis track are both provided with a threaded knob, the bottom surface of the X-axis track is slidably connected to the fixed base through the threaded knob, the bottom surface of the Y-axis track is slidably connected to the top surface of the X-axis track through the threaded knob, and the fixed component is arranged at the center position of the top surface of the Y-axis track.

4. A magnetically compatible rodent brain injection device according to claim 3, characterized in that: The injection catheter system includes a drug administration sleeve and a positioning catheter sleeved on the outer wall of the drug administration sleeve, one end of the positioning catheter is fixedly connected to the fixing assembly, and the other end of the positioning catheter is provided with a fastening knob. The drug administration sleeve is fixedly connected to the positioning catheter via the fastening knob, and the outer wall of the fastening knob is provided with anti-slip grooves.

5. A magnetically compatible rodent brain injection device according to claim 4, characterized in that: The outer diameter of the drug administration sleeve is equal to the inner diameter of the positioning catheter, and the length of the drug administration sleeve is greater than the length of the positioning catheter.

6. A magnetically compatible rodent brain injection device according to claim 4, characterized in that: The drug delivery sleeve is made of quartz material, and the positioning catheter and the fastening knob are both made of non-metallic materials.

7. A magnetically compatible rodent brain injection device according to claim 1, characterized in that: The fixed base and the stereo positioning fine-tuning system are both made of non-metallic materials, specifically one of polyetheretherketone or Teflon.

8. A magnetically compatible rodent brain injection device according to claim 1, characterized in that: The drug delivery system comprises a PE tube, a micro-injection syringe and a micro-injection pump, and the micro-injection syringe adopts a threaded knob advancement design.

9. A magnetically compatible rodent brain injection method, using the magnetically compatible rodent brain injection device according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Fixation and positioning: Fix the animal on the stereotaxic instrument, ensure that the head surface is parallel to the horizontal plane of the stereotaxic instrument, open the animal's scalp, expose the skull, and drill a hole in the skull above the target area to a depth that reaches the surface of the dura mater; S2. Installation of the fixed base and positioning catheter: Bond the fixed base to the skull around the drill hole, install the positioning catheter after curing, lock it on the stereotaxic fine-tuning system, and adjust the XY direction to make the positioning catheter face the drill hole; S3. Preparation of dosing cannula: connect the dosing cannula pre-filled with a set dose of injection liquid to a PE tube pre-filled with physiological saline. The PE tube runs through the inside and outside of the nuclear magnetic resonance environment. The external PE tube is connected to the micro-syringe and fixed on the micro-syringe pump. S4, animal MRI scanning: transfer the animal obtained in S2 to the scanning workroom, fix it, monitor physiological indicators, and then insert the drug administration cannula obtained in S3 into the positioning catheter. After reaching the target depth, use the knob to fix the drug administration cannula and the positioning catheter; S5, checking whether the target area is accurately positioned by magnetic resonance structural imaging scanning, if the target area is not reached, repeating S4 until the positioning is accurate; S6. Drug injection: Start the microinjection pump to inject the set dose of injection liquid, saline and blood at the preset rate, and use MRI for imaging to check the distribution of the liquid in the brain; S7. Remove the drug delivery cannula: If subsequent experimental injections are required at the same location, install a protective cover to cover the positioning catheter at the drilling location. If no subsequent experiments are to be performed, remove the positioning catheter and seal the wound.

10. A magnetically compatible rodent brain injection method according to claim 9, characterized in that: S6 further includes the following steps: Start the microinjection pump, and first inject the deep nuclei at a preset rate and a set dose of liquid. Let it stand, then use MRI for imaging, and then adjust the depth of the dosing cannula upwards, and then fix it with the tightening knob, and inject the set dose of liquid into the cortex to check the distribution of the liquid in the brain.

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