An anti-interference magnetic resonance (MRI) scan positioning line and a preparation method thereof

Abstract

The application discloses an anti-interference magnetic resonance (MRI) scanning positioning line and a preparation method thereof, and relates to the technical field of medical devices. The preparation method of the anti-interference MRI scanning positioning line comprises the following steps: adding a dispersion solution of Pt3Co@SiO2@W developing particles, carbon fluoride nanotubes and isomeric alkane lubricant into a dispersion solution of polytetrafluoroethylene, stirring, sealing and drying to obtain mixed powder; bidirectionally pressing the mixed powder in a mold to obtain a blank; melt-extruding the blank to obtain nascent fibers; and obtaining the anti-interference MRI scanning positioning line after sintering, heat stretching and heat setting of the nascent fibers. The anti-interference MRI scanning positioning line prepared by the application has the advantages of high development, anti-interference, strong mechanics and low toxicity, and can fully meet the requirements of clinical MRI / CT bimodal interventional positioning.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to an anti-interference magnetic resonance MRI scanning positioning line and its preparation method. Background Technology

[0002] Image-guided minimally invasive interventional medicine is an interdisciplinary field that integrates imaging diagnosis and clinical treatment. It refers to minimally invasive diagnostic or therapeutic procedures performed percutaneously using various needles, guidewires, catheters, and other interventional devices under the guidance and monitoring of imaging technologies (including ultrasound, X-ray, CT, MRI, etc.). Compared to traditional surgical procedures, image-guided surgery is less invasive, has more definite therapeutic effects, lower costs, and fewer complications.

[0003] Magnetic resonance imaging (MRI), with its advantages of no ionizing radiation, high soft tissue resolution, and multi-planar tomographic imaging, has become a core technology for clinical imaging diagnosis, intraoperative navigation, and precise radiotherapy localization. In MRI scanning and interventional procedures, the scanning localization line is a key consumable for achieving precise lesion localization, scanning plane calibration, and intraoperative path guidance, directly determining diagnostic accuracy and operational safety. Currently, commonly used MRI positioning lines in clinical practice mostly employ ordinary polymer fibers, metal wires, or coated imaging lines, which have several technical drawbacks: First, traditional metal positioning lines are prone to magnetic susceptibility artifacts and electromagnetic interference in strong magnetic field environments, leading to image distortion, positioning deviations, and even interference with magnetic field homogeneity. Second, ordinary polymer positioning lines have no imaging effect and require additional coating with contrast agent, resulting in problems such as contrast layer peeling and insufficient imaging clarity, failing to meet the needs of locating small lesions and fine structures. Third, conventional positioning lines have poor flexibility and uneven wire diameter, easily shifting when conforming to the curved surface of the human body, and have poor biocompatibility, posing a risk of sensitization with long-term contact with the human body. Fourth, existing positioning lines have weak anti-interference capabilities and are easily affected by electromagnetic signals from scanning equipment and ambient noise, further reducing positioning accuracy. Therefore, existing MRI scanning positioning lines have defects such as unclear imaging, low anti-interference capabilities, and poor flexibility, which greatly limits the use of this technology. Summary of the Invention

[0004] The purpose of this invention is to provide an anti-interference magnetic resonance MRI scanning positioning line and its preparation method, thereby solving the following technical problems: Existing magnetic resonance MRI scanning positioning lines suffer from problems such as unclear imaging, low anti-interference ability, and poor flexibility.

[0005] The objective of this invention can be achieved through the following technical solutions: A method for preparing anti-interference magnetic resonance MRI scanning positioning lines includes at least the following preparation steps: A dispersion of Pt3Co@SiO2@W developing particles, fluorinated carbon nanotubes, and isoparaffinic lubricant were added to a dispersion of polytetrafluoroethylene, stirred, sealed, and dried to obtain a mixed powder. The mixed powder is added to a mold and pressed bidirectionally to obtain a blank; The preform is melt-extruded and molded to obtain nascent fibers; After the nascent fibers are sintered, hot-stretched and heat-set, anti-interference magnetic resonance MRI scanning positioning lines are obtained.

[0006] As a further aspect of the present invention: the mass ratio of the Pt3Co@SiO2@W developing particles, the fluorinated carbon nanotubes, and the polytetrafluoroethylene is 0.5-2.5:0.03-0.2:100.

[0007] As a further aspect of the present invention: the diameter of the anti-interference magnetic resonance MRI scanning positioning line is 50-100μm.

[0008] As a further aspect of the present invention, the method for preparing the Pt3Co@SiO2@W developing particles includes at least the following preparation steps: 1,2-Dodecanediol, platinum acetylacetonate, cobalt octacarbonyl, dibenzyl ether, oleylamine and oleic acid were mixed and heated to react, cooled and washed, and then dispersed in cyclohexane to obtain a cyclohexane dispersion of Pt3Co. The surfactant was dissolved in cyclohexane, and a cyclohexane dispersion of Pt3Co was added dropwise. Ammonia water was added and stirred continuously. Then, tetraethyl orthosilicate was added dropwise and stirred to react. After precipitation, centrifugation and washing, the cyclohexane dispersion of Pt3Co@SiO2 was obtained. Oleylamine and 1-octadecene were added to the cyclohexane dispersion of Pt3Co@SiO2, stirred and heated, and oleylamine solution of tungsten hexachloride was added under argon protection. The mixture was heated and reacted, precipitated, centrifuged and washed, and then dispersed in cyclohexane to obtain a dispersion of Pt3Co@SiO2@W developing particles.

[0009] As a further aspect of the present invention, the mass ratio of the platinum acetylacetonate to the cobalt octacarbonyl is 4-6:1.

[0010] As a further aspect of the present invention: the mass ratio of Pt3Co@SiO2 to tungsten hexachloride is 1:8-12.

[0011] As a further aspect of the present invention, the mass ratio of Pt3Co to tetraethyl orthosilicate is 1:20-50.

[0012] As a further aspect of the present invention, the method for preparing the fluorinated carbon nanotubes includes at least the following preparation steps: Carbon nanotubes and polytetrafluoroethylene were added to a crucible and mixed. After reacting at 450-550℃ for 0.5-1.5h, the mixture was ultrasonically dispersed in ethanol, allowed to stand, washed, filtered and dried to obtain fluorinated carbon nanotubes.

[0013] As a further aspect of the present invention: the mass ratio of the carbon nanotubes to the polytetrafluoroethylene is 1:8-10, and the length of the fluorinated carbon nanotubes is 10-50 μm.

[0014] An anti-interference magnetic resonance MRI scanning positioning line, made by any of the preparation methods described above.

[0015] The beneficial effects of this invention are: This invention provides an anti-interference magnetic resonance MRI (MRI) scanning positioning line and its preparation method. High-performance fibers are obtained by uniformly dispersing multi-level structured Pt3Co@SiO2@W imaging particles and fluorinated carbon nanotubes in a polytetrafluoroethylene (PTFE) matrix, followed by biaxial pressing, extrusion molding, sintering, and hot stretching. The prepared anti-interference MRI scanning positioning line exhibits a clear and stable negative contrast signal under MRI, possesses excellent anti-electromagnetic interference capabilities, eliminates the risk of eddy current heating, and also has good X-ray imaging properties. It is perfectly compatible with multimodal imaging navigation systems such as MRI and CT, providing a precise and safe positioning solution for minimally invasive interventional surgery.

[0016] The Pt3Co@SiO2@W imaging particles prepared in this invention possess a unique multilayer structure. The core is composed of Pt3Co alloy nanoparticles. Utilizing the difference in magnetic susceptibility between platinum and cobalt, local field distortion is generated in a magnetic field, resulting in a significant negative contrast (signal loss) effect, achieving highly sensitive MRI imaging. The SiO2 insulating layer encapsulates the Pt3Co alloy nanoparticles, acting as a dielectric isolation layer that effectively blocks electron exchange between the core and the outer shell, preventing eddy currents in the radio frequency field and fundamentally eliminating the potential for thermal effects. Simultaneously, the SiO2 layer protects the core from chemical corrosion, improving the material's biocompatibility and biocompatibility. Furthermore, a tungsten outer shell layer is formed on the SiO2 insulating layer using liquid phase deposition, endowing the imaging particles with excellent X-ray attenuation capabilities. This ensures that the prepared positioning lines are clearly visible under CT, meeting the clinical needs of multimodal image fusion. The Pt3Co@SiO2@W developing particles prepared by this invention have excellent compatibility with polytetrafluoroethylene matrix, which not only ensures developing sensitivity, but also completely solves the problems of magnetic field interference and image artifacts caused by traditional metal developing agents, achieving a synergistic improvement in developing performance and anti-interference performance.

[0017] This invention also introduces fluorinated carbon nanotubes, employing a high-temperature solid-phase fluorination modification process. Polytetrafluoroethylene (PTFE) is used as the fluorine source to controllably fluorinate the carbon nanotubes, introducing fluorine atoms into the nanotube walls. The fluorinated carbon nanotubes prepared by this invention not only inherit the excellent mechanical properties of carbon nanotubes, but also significantly enhance the tensile strength and flexibility of the PTFE substrate, meeting the mechanical performance requirements for repeated bending and puncture guidance as a positioning line. Simultaneously, the fluorination treatment introduces a large number of fluorine atoms onto the surface of the carbon nanotubes, greatly reducing the dielectric constant and conductivity of the material, further strengthening the electromagnetic inertia of the positioning line, ensuring no signal interference or thermal effects in the MRI radio frequency field. Furthermore, the uniformly dispersed fluorinated carbon nanotubes synergistically interact with Pt3Co@SiO2@W imaging particles to form a stable antistatic and anti-electromagnetic interference network within the PTFE substrate, guaranteeing the signal stability and safety of the positioning line during long-term use. Detailed Implementation

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1: The preparation method of Pt3Co@SiO2@W developing particles includes the following steps: Mix 0.3 g 1,2-dodecanediol, 0.5 g platinum acetylacetonate, 0.11 g cobalt octacarbonyl, 80 ml dibenzyl ether, 80 ml oleylamine and 10 ml oleic acid and heat to 100 °C for about 30 min. Then slowly raise the temperature to 200 °C and react for 1.5 h. Stop heating and cool to room temperature. Wash twice with anhydrous ethanol and disperse in cyclohexane to obtain a cyclohexane dispersion of Pt3Co with a concentration of 20 mg / mL. 2g of nonylphenol polyoxyethylene ether was dissolved in 40mL of cyclohexane, 10mL of the above Pt3Co cyclohexane dispersion was added dropwise, 0.4mL of 28wt% ammonia water was added and stirred continuously, then 7g of tetraethyl orthosilicate was added dropwise and stirred at room temperature for 24h. 100mL of anhydrous ethanol was added to precipitate the precipitate, centrifuged at 9000rpm for 15 minutes, washed 4 times by centrifugation, and dispersed in cyclohexane to obtain a Pt3Co@SiO2 cyclohexane dispersion with a concentration of 20mg / mL. Nanoparticles were dispersed in 5 mL of cyclohexane. 5 mL of oleylamine and 5 mL of 1-octadecene were added to the 10 mL cyclohexane dispersion of Pt3Co@SiO2. Under magnetic stirring, the mixture was slowly heated to 120 °C, and the vacuum pump was turned on and maintained for 30 minutes. Under argon protection, 2 g of tungsten hexachloride was weighed and dissolved in 2 mL of oleylamine to prepare an oleylamine solution of tungsten hexachloride. The oleylamine solution of tungsten hexachloride was rapidly injected into the reaction system, and the temperature was rapidly increased to 290 °C at a rate of 15 °C / min and maintained for 1.5 h. After the reaction was completed, the heat source was removed, and the mixture was allowed to cool naturally to 60 °C. 50 mL of anhydrous ethanol was added to precipitate the particles. The mixture was centrifuged at 6000 rpm for 8-10 minutes, washed, and the process was repeated 3 times. The precipitate was then dispersed in 20 mL of cyclohexane to obtain a dispersion of Pt3Co@SiO2@W developing particles with a concentration of 10 mg / mL.

[0020] Example 2: The preparation method of fluorinated carbon nanotubes includes the following steps: 1g of carbon nanotubes and 9g of polytetrafluoroethylene (M-111) were mixed evenly in a crucible and placed in a box-type resistance furnace filled with argon gas and sealed. The mixture was reacted at 500℃ for 1h. After the reaction was completed, the products were taken out separately, added to ethanol solution and ultrasonically dispersed for 0.5h. After standing for 1h, the ethanol dispersion of the upper fluorinated carbon nanotubes was added to a Buchner funnel for filtration and washed with deionized water. After filtration, the mixture was dried at 100℃ for 2h to obtain fluorinated carbon nanotubes.

[0021] Example 3: The method for preparing anti-interference magnetic resonance MRI scanning positioning lines includes the following steps: 360 mL of the dispersion of Pt3Co@SiO2@W developing particles prepared in Example 1, 0.36 g of fluorinated carbon nanotubes prepared in Example 2, and 25 g of isoparaffinic lubricant (Isopar L) were added to 1000 g of polytetrafluoroethylene dispersion (F104, solid content 60 wt%), stirred for 2 h, sealed, and dried at 80 °C for 12 h to obtain mixed powder; The above-mentioned mixed powder was loaded into a mold and pressed bidirectionally at 30MPa for 5 minutes to obtain a blank. After preheating the above-mentioned preform at 250°C, it is extruded and molded by an extruder to obtain nascent fibers; The nascent fibers were sintered at 360°C for 1 hour, then hot-stretched at 280°C (stretch ratio 3 times), and finally heat-set at 200°C for 30 minutes to obtain an anti-interference magnetic resonance MRI scanning positioning line with a diameter of about 75 μm.

[0022] Example 4: The method for preparing anti-interference magnetic resonance MRI scanning positioning lines includes the following steps: 1080 mL of the dispersion of Pt3Co@SiO2@W developing particles prepared in Example 1, 0.72 g of fluorinated carbon nanotubes prepared in Example 2, and 27 g of isoparaffinic lubricant (Isopar L) were added to 1000 g of polytetrafluoroethylene dispersion (F104, solid content 60 wt%), stirred for 2 h, sealed, and dried at 80 °C for 12 h to obtain mixed powder; The above-mentioned mixed powder was loaded into a mold and pressed bidirectionally at 35 MPa for 5 minutes to obtain a blank. After preheating the above-mentioned preform at 250°C, it is extruded and molded by an extruder to obtain nascent fibers; The nascent fibers were sintered at 370°C for 1 hour, then hot-stretched at 290°C (stretch ratio 3 times), and finally heat-set at 220°C for 30 minutes to obtain an anti-interference magnetic resonance MRI scanning positioning line with a diameter of about 75 μm.

[0023] Example 5: The method for preparing anti-interference magnetic resonance MRI scanning positioning lines includes the following steps: 1440 mL of the dispersion of Pt3Co@SiO2@W developing particles prepared in Example 1, 1.08 g of fluorinated carbon nanotubes prepared in Example 2, and 30 g of isoparaffinic lubricant (Isopar L) were added to 1000 g of polytetrafluoroethylene dispersion (F104, solid content 60 wt%), stirred for 2 h, sealed, and dried at 80 °C for 12 h to obtain mixed powder; The above-mentioned mixed powder was loaded into a mold and pressed bidirectionally at 40MPa for 5 minutes to obtain a blank. After preheating the above-mentioned preform at 250°C, it is extruded and molded by an extruder to obtain nascent fibers; The nascent fibers were sintered at 380°C for 1 hour, then hot-stretched at 300°C (stretch ratio 3 times), and finally heat-set at 250°C for 30 minutes to obtain an anti-interference magnetic resonance MRI scanning positioning line with a diameter of about 75 μm.

[0024] Comparative Example 1: The method for preparing anti-interference magnetic resonance MRI scanning positioning lines includes the following steps: 540 mL of the cyclohexane dispersion of Pt3Co prepared in Example 1, 0.72 g of the fluorinated carbon nanotubes prepared in Example 2, and 27 g of isoparaffinic lubricant (Isopar L) were added to 1000 g of polytetrafluoroethylene dispersion (F104, solid content 60 wt%), stirred for 2 h, sealed, and dried at 80 °C for 12 h to obtain a mixed powder. The above-mentioned mixed powder was loaded into a mold and pressed bidirectionally at 35 MPa for 5 minutes to obtain a blank. After preheating the above-mentioned preform at 250°C, it is extruded and molded by an extruder to obtain nascent fibers; The nascent fibers were sintered at 370°C for 1 hour, then hot-stretched at 290°C (stretch ratio 3 times), and finally heat-set at 220°C for 30 minutes to obtain an anti-interference magnetic resonance MRI scanning positioning line with a diameter of about 75 μm.

[0025] Comparative Example 2: The method for preparing anti-interference magnetic resonance MRI scanning positioning lines includes the following steps: 540 mL of the cyclohexane dispersion of Pt3Co@SiO2 prepared in Example 1, 0.72 g of the fluorinated carbon nanotubes prepared in Example 2, and 27 g of isoparaffinic lubricant (Isopar L) were added to 1000 g of polytetrafluoroethylene dispersion (F104, solid content 60 wt%), stirred for 2 h, sealed, and dried at 80 °C for 12 h to obtain a mixed powder. The above-mentioned mixed powder was loaded into a mold and pressed bidirectionally at 35 MPa for 5 minutes to obtain a blank. After preheating the above-mentioned preform at 250°C, it is extruded and molded by an extruder to obtain nascent fibers; The nascent fibers were sintered at 370°C for 1 hour, then hot-stretched at 290°C (stretch ratio 3 times), and finally heat-set at 220°C for 30 minutes to obtain an anti-interference magnetic resonance MRI scanning positioning line with a diameter of about 75 μm.

[0026] Comparative Example 3: The method for preparing anti-interference magnetic resonance MRI scanning positioning lines includes the following steps: 10.8g of medical ultrafine W powder (DK-W-001), 0.72g of fluorinated carbon nanotubes prepared in Example 2, and 27g of isoparaffin lubricant (Isopar L) were added to a dispersion of 1000g of polytetrafluoroethylene (F104, solid content 60wt%), stirred for 2h, sealed, and dried at 80℃ for 12h to obtain a mixed powder. The above-mentioned mixed powder was loaded into a mold and pressed bidirectionally at 35 MPa for 5 minutes to obtain a blank. After preheating the above-mentioned preform at 250°C, it is extruded and molded by an extruder to obtain nascent fibers; The nascent fibers were sintered at 370℃ for 1 hour, then hot-stretched at 290℃ (stretch ratio 3 times), and finally heat-set at 220℃ for 30 minutes to obtain an anti-interference magnetic resonance MRI scan positioning line with a diameter of approximately 75 μm. Comparative Example 4: The method for preparing anti-interference magnetic resonance MRI scanning positioning lines includes the following steps: 1080 mL of the dispersion of Pt3Co@SiO2@W developing particles prepared in Example 1, 0.72 g of unfluorinated carbon nanotubes from Example 2, and 27 g of isoparaffinic lubricant (Isopar L) were added to 1000 g of polytetrafluoroethylene dispersion (F104, solid content 60 wt%), stirred for 2 h, sealed, and dried at 80 °C for 12 h to obtain mixed powder; The above-mentioned mixed powder was loaded into a mold and pressed bidirectionally at 35 MPa for 5 minutes to obtain a blank. After preheating the above-mentioned preform at 250°C, it is extruded and molded by an extruder to obtain nascent fibers; The nascent fibers were sintered at 370°C for 1 hour, then hot-stretched at 290°C (stretch ratio 3 times), and finally heat-set at 220°C for 30 minutes to obtain an anti-interference magnetic resonance MRI scanning positioning line with a diameter of about 75 μm.

[0027] Comparative Example 5: The method for preparing anti-interference magnetic resonance MRI scanning positioning lines includes the following steps: 1080 mL of the dispersion of Pt3Co@SiO2@W developing particles prepared in Example 1 and 27 g of isoparaffinic lubricant (Isopar L) were added to 1000 g of polytetrafluoroethylene dispersion (F104, solid content 60 wt%), stirred for 2 h, sealed and dried at 80 °C for 12 h to obtain mixed powder. The above-mentioned mixed powder was loaded into a mold and pressed bidirectionally at 35 MPa for 5 minutes to obtain a blank. After preheating the above-mentioned preform at 250°C, it is extruded and molded by an extruder to obtain nascent fibers; The nascent fibers were sintered at 370°C for 1 hour, then hot-stretched at 290°C (stretch ratio 3 times), and finally heat-set at 220°C for 30 minutes to obtain an anti-interference magnetic resonance MRI scanning positioning line with a diameter of about 75 μm.

[0028] Comparative Example 6: The method for preparing anti-interference magnetic resonance MRI scanning positioning lines includes the following steps: 27g of isoparaffin lubricant (Isopar L) was added to 1000g of polytetrafluoroethylene dispersion (F104, solid content 60wt%), stirred for 2h, sealed and dried at 80℃ for 12h to obtain powder. The above powder is loaded into a mold and pressed bidirectionally at 35MPa for 5 minutes to obtain a blank. After preheating the above-mentioned preform at 250°C, it is extruded and molded by an extruder to obtain nascent fibers; The nascent fibers were sintered at 370°C for 1 hour, then hot-stretched at 290°C (stretch ratio 3 times), and finally heat-set at 220°C for 30 minutes to obtain an anti-interference magnetic resonance MRI scanning positioning line with a diameter of about 75 μm.

[0029] Performance testing Mechanical property testing: The tensile properties of chemical fiber filaments were tested according to GB / T 14344-2022 "Test Method for Tensile Properties of Chemical Fiber Filaments". The breaking strength (cN / dtex) and breaking elongation (%) of the anti-interference magnetic resonance MRI scanning positioning lines prepared in Examples 3-5 and Comparative Examples 1-6 were tested using a micro-force universal testing machine. The initial clamping distance was 100 mm and the tensile speed was 100 mm / min. The test results are shown in Table 1. Cytotoxicity assay: The interference-resistant MRI scanning localization lines prepared in Examples 3-5 and Comparative Examples 1-6 were cut into small pieces and added to DMEM medium containing 10% fetal bovine serum at a ratio of 0.2 g / mL. The mixture was extracted at 37°C for 72 h, and the extract was collected for later use. L929 mouse fibroblasts were then subjected to a 1×10⁻⁶ cytotoxicity assay. 4 Cells were seeded per well in 96-well plates and cultured for 24 hours. The original culture medium was discarded, and extracts from each group were added. A negative control (fresh DMEM medium) and a positive control (DMEM medium containing 0.1% phenol) were included. After 48 hours of culture, MTT solution (5 mg / mL, 20 μL / well) was added to each well, and the cells were cultured for another 4 hours. The supernatant was discarded, and 150 μL of DMSO was added to dissolve formazan crystals. The OD value at 570 nm was measured using a microplate reader. Cell viability was calculated using the following formula: Cell viability (%) = (OD value of experimental group / OD value of negative control group) x 100%. The final experimental results were obtained by calculating the average and standard deviation of the five parallel experimental data. The results are shown in Table 1. In vitro MRI scanning test: The anti-interference MRI scanning positioning lines obtained in Examples 3-5 and Comparative Examples 1-6 were fixed parallel to the surface of the agarose gel phantom. Gradient echo (GRE) sequence images (TR / TE=500ms / 15ms, flip angle 20°) were acquired on a 3.0T MRI scanner. Regions of interest (ROIs, area ≥20mm²) were delineated in the positioning line area and the background area, respectively. 2 Record the signal strength (SI) and calculate the contrast-to-noise ratio (CNR): CNR = |SI| 定位线 -SI 背景 | / SD 背景 The test results are shown in Table 1. CT signal intensity test: The anti-interference magnetic resonance MRI scan localization devices obtained in Examples 3-5 and Comparative Examples 1-6 were fixed in polymethyl methacrylate (PMMA) phantoms, which were filled with water. Multi-slice spiral CT scans were performed (tube voltage 120kV, tube current 200mAs, slice thickness 1mm). After reconstruction, Regions of Interest (ROIs) were delineated in the localization line area and the background area, and the CT values ​​(HU) were recorded. The net intensity of the imaging was calculated by subtracting the background CT value from the localization line CT value. The test results are shown in Table 1. Table 1: Statistical Table of Performance Test Data for Examples and Comparative Examples

[0030] As shown in Table 1, the anti-interference MRI scanning positioning line prepared by this invention possesses high imaging activity, anti-interference properties, strong mechanical properties, and low toxicity, fully meeting the clinical MRI / CT dual-modal interventional positioning requirements. In Comparative Example 1, the Pt3Co particles added for imaging resulted in the largest MRI artifact area, significantly reduced cell viability, and weak CT imaging ability in the anti-interference MRI scanning positioning line. This indicates that the lack of a SiO2 insulating layer leads to severe eddy current artifacts, while cobalt ion leakage causes cytotoxicity, and the lack of a tungsten layer results in insufficient X-ray attenuation. In Comparative Example 2, the Pt3Co@SiO2 particles added for imaging resulted in a significant decrease in CT signal intensity in the anti-interference MRI scanning positioning line, indicating that the lack of a tungsten layer cannot provide sufficient X-ray attenuation. In Comparative Example 3, the medical ultrafine tungsten powder added for imaging resulted in an extremely low MRI contrast-to-noise ratio and severe image artifacts in the anti-interference MRI scanning positioning line, indicating that tungsten powder alone lacks a magnetic core and cannot produce negative MRI contrast. Metal particles are prone to generating magnetic susceptibility artifacts in magnetic fields, interfering with imaging. In Comparative Example 4, the carbon nanotubes added were not fluorinated, resulting in low MRI artifact area, fracture strength, and cell viability in the obtained anti-interference MRI scanning positioning line image. This indicates that ordinary carbon nanotubes have strong conductivity and are prone to generating eddy current interference signals in the MRI radio frequency field. Fluorination treatment effectively reduced dielectric loss and electromagnetic interference. In Comparative Example 5, no fluorinated carbon nanotube filler was added, resulting in a significant decrease in the mechanical properties of the obtained anti-interference MRI scanning positioning line. This indicates that fluorinated carbon nanotubes played a key role in strengthening and toughening, and their absence would lead to insufficient mechanical properties of the positioning line, making it prone to breakage during surgery. Comparative Example 6 served as a blank control, and the obtained anti-interference MRI scanning positioning line showed no imaging effect on MRI or CT, and had the worst mechanical properties.

[0031] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0032] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A method for preparing anti-interference magnetic resonance MRI scanning positioning lines, characterized in that, It includes at least the following preparation steps: A dispersion of Pt3Co@SiO2@W developing particles, fluorinated carbon nanotubes, and isoparaffinic lubricant were added to a dispersion of polytetrafluoroethylene, stirred, sealed, and dried to obtain a mixed powder. The mixed powder is added to a mold and pressed bidirectionally to obtain a blank; The preform is melt-extruded and molded to obtain nascent fibers; After the nascent fibers are sintered, hot-stretched and heat-set, anti-interference magnetic resonance MRI scanning positioning lines are obtained.

2. The method for preparing an anti-interference magnetic resonance MRI scanning positioning line according to claim 1, characterized in that, The mass ratio of the Pt3Co@SiO2@W developing particles, the fluorinated carbon nanotubes, and the polytetrafluoroethylene is 0.5-2.5:0.03-0.2:

100.

3. The method for preparing an anti-interference magnetic resonance MRI scanning positioning line according to claim 1, characterized in that, The diameter of the anti-interference magnetic resonance MRI scanning positioning line is 50-100 μm.

4. The method for preparing an anti-interference magnetic resonance MRI scanning positioning line according to claim 1, characterized in that, The preparation method of the Pt3Co@SiO2@W developing particles includes at least the following preparation steps: 1,2-Dodecanediol, platinum acetylacetonate, cobalt octacarbonyl, dibenzyl ether, oleylamine and oleic acid were mixed and heated to react, cooled and washed, and then dispersed in cyclohexane to obtain a cyclohexane dispersion of Pt3Co. The surfactant was dissolved in cyclohexane, and a cyclohexane dispersion of Pt3Co was added dropwise. Ammonia water was added and stirred continuously. Then, tetraethyl orthosilicate was added dropwise and stirred to react. After precipitation, centrifugation and washing, the cyclohexane dispersion of Pt3Co@SiO2 was obtained. Oleylamine and 1-octadecene were added to the cyclohexane dispersion of Pt3Co@SiO2, stirred and heated, and oleylamine solution of tungsten hexachloride was added under argon protection. The mixture was heated and reacted, precipitated, centrifuged and washed, and then dispersed in cyclohexane to obtain a dispersion of Pt3Co@SiO2@W developing particles.

5. The method for preparing an anti-interference magnetic resonance MRI scanning positioning line according to claim 4, characterized in that, The mass ratio of platinum acetylacetonate to cobalt octacarbonyl is 4-6:

1.

6. The method for preparing an anti-interference magnetic resonance MRI scanning positioning line according to claim 4, characterized in that, The mass ratio of Pt3Co@SiO2 to tungsten hexachloride is 1:8-12.

7. The method for preparing an anti-interference magnetic resonance MRI scanning positioning line according to claim 4, characterized in that, The mass ratio of Pt3Co to tetraethyl orthosilicate is 1:20-50.

8. The method for preparing an anti-interference magnetic resonance MRI scanning positioning line according to claim 1, characterized in that, The preparation method of the fluorinated carbon nanotubes includes at least the following preparation steps: Carbon nanotubes and polytetrafluoroethylene were added to a crucible and mixed. After reacting at 450-550℃ for 0.5-1.5h, the mixture was ultrasonically dispersed in ethanol, allowed to stand, washed, filtered and dried to obtain fluorinated carbon nanotubes.

9. The method for preparing an anti-interference magnetic resonance MRI scanning positioning line according to claim 8, characterized in that, The mass ratio of the carbon nanotubes to the polytetrafluoroethylene is 1:8-10, and the length of the fluorinated carbon nanotubes is 10-50 μm.

10. An anti-interference magnetic resonance MRI scanning positioning line, characterized in that, It is prepared by the method described in any one of claims 1-9.

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