Interventional radio frequency coil and method of using the same

Abstract

The application relates to the medical technical field, in particular to an interventional radio frequency coil and a use method thereof. The interventional radio frequency coil comprises a multi-cavity catheter, a line channel, an inner balloon channel, an outer balloon channel and a endoscope channel are arranged in the multi-cavity catheter; an inner balloon is arranged on the surface of the multi-cavity catheter, the inner balloon is communicated with the inner balloon channel, and the inflation state of the inner balloon is adjusted through the inner balloon channel; a coil main body is arranged on the outer surface of the inner balloon, the shape of the coil main body can be adjusted through the inflation or pressure relief of the inner balloon, and the line of the coil main body is led out through the line channel; an outer balloon is arranged on the surface of the multi-cavity catheter and located outside the inner balloon and the coil main body; the inflation state of the outer balloon can be adjusted through the outer balloon channel, wherein: the outer balloon tightly holds the coil main body when pressure relief; when the outer balloon is inflated, surrounding tissues can be expanded to separate the coil main body from the tissues. The scheme is used to realize high signal-to-noise ratio and high resolution imaging of deep tissues or cavities in magnetic resonance.

Description

Technical Field

[0001] This invention relates to the field of medical technology, and in particular to an interventional radiofrequency coil and its method of use. Background Technology

[0002] Magnetic resonance imaging (MRI) is a powerful and information-rich medical imaging device that can provide detailed anatomical information of the human body as well as physiological information such as biochemical metabolism of tissues, making it of great value in clinical diagnosis and scientific research. However, the magnetic resonance signals acquired by MRI are very weak and easily interfered with by human tissue noise and other environmental factors. Therefore, the signal-to-noise ratio of the imaging system has a decisive impact on image quality.

[0003] In the magnetic resonance signal receiver chain, the radio frequency (RF) coil, as the front-end detection device, directly affects the signal reception efficiency and the signal-to-noise ratio (SNR) of the image. In traditional electromagnetics and nuclear magnetic resonance (NMR) technology, the RF coil is also referred to as a resonator or probe. According to electromagnetic field theory and the propagation characteristics of RF signals, under the same conditions, the amplitude of the signal received by the coil increases significantly as the distance between it and the object being imaged decreases. Therefore, placing the RF coil as close as possible to the target tissue, especially for organs or lesions located deep within the body, can significantly improve signal sensitivity and image SNR. If the coil can be placed inside a body cavity and close to the target area, image quality can be effectively improved.

[0004] Currently, routine clinical MRI examinations typically employ a birdcage-type body coil as the radiofrequency excitation source to achieve uniform excitation over a large area; simultaneously, a surface coil is used as the signal receiving device, closely attached to the body surface to improve the receiving sensitivity in local areas. While this configuration performs well in superficial tissue imaging, it has significant limitations when imaging deep internal organs or lesions such as the stomach, rectum, and uterus. Because the surface coil is located outside the body, there is a considerable distance between it and the target tissue, resulting in a significant reduction in the fill factor, a corresponding attenuation of the received magnetic resonance signal intensity, and a sharp decrease in the signal-to-noise ratio. Furthermore, the signal must pass through intermediate tissues during its propagation path, making it susceptible to interference or attenuation, further degrading image quality.

[0005] Especially for early lesions, whose signals are weak, if the coil is too far away to be effectively captured, it is easily submerged in the image, making the lesion difficult to detect and increasing the risk of missed or misdiagnosis. Therefore, the detection sensitivity and image contrast of existing surface coils placed on the body surface are no longer sufficient to meet the needs of precision medicine in deep tissue imaging.

[0006] To overcome the limitations of traditional surface coils in deep tissue magnetic resonance imaging, a new type of radio frequency receiving coil that can be placed within body cavities has been developed in recent years. This aims to significantly improve local signal response by directly inserting the coil into natural cavities such as the digestive, genitourinary, or respiratory tracts, bringing it close to the target lesion. These intracavitary coils are typically designed as foldable or expandable structures for insertion via endoscopy or catheters and deployment at the target location. However, existing intracavitary coils still face several challenges in practical applications: Firstly, mechanical deployment mechanisms (such as sliding supports or elastic support structures) are susceptible to tissue deformation, peristalsis, or cavity collapse in complex cavity environments, leading to coil instability and difficulty in maintaining consistent contact with the lesion area. Secondly, repeated deformation of the coil assembly during deployment can cause wire breakage or circuit connection failure, affecting equipment reliability and lifespan. Furthermore, rigid or semi-rigid support structures pose a risk of scratching the mucosa during movement within the body, affecting patient comfort and potentially causing iatrogenic injury, limiting their long-term application in flexible cavities or dynamic organs.

[0007] Furthermore, for small lesions located within solid organs or deep vascular networks (such as early tumor infiltration, microaneurysms, or vascular malformations), effective signal capture remains difficult even with intracavitary coils. Against this backdrop, inserting radiofrequency coils along catheters into the vascular system to achieve in-situ imaging of deep vascular beds in the cardiovascular, cerebral, pulmonary, and hepatic systems has become a cutting-edge research direction for improving the sensitivity of magnetic resonance imaging (MRI). Intravascular radiofrequency coils can directly enter the target feeding artery, receiving signals adjacent to the lesion area. Theoretically, this can significantly improve the local signal-to-noise ratio and spatial resolution, providing unprecedented imaging capabilities for early vascular lesions, plaque vulnerability assessment, and tumor microenvironment analysis. However, the design of intravascular coils faces more stringent technical requirements: miniaturization, flexibility, and mechanical safety must be considered to adapt to complex vascular pathways and be delivered via interventional catheters; simultaneously, issues such as electromagnetic interference, thermal effects, and motion artifacts caused by the radiofrequency feeder must be addressed. Currently, a mature solution that combines high sensitivity, good biocompatibility, and clinical feasibility is lacking.

[0008] In summary, despite numerous attempts to improve the performance of deep tissue magnetic resonance imaging (MRI), all methods—including surface coils, deployable coils within body cavities, and the exploratory intravascular coils—have limitations in terms of detection sensitivity, structural stability, operational safety, and clinical applicability. Therefore, there is an urgent need to develop novel radiofrequency receiving coil structures or imaging methods to achieve efficient, safe, and stable detection of deep organs and early, minute lesions, thereby comprehensively improving the accuracy and reliability of MRI in the diagnosis of complex diseases, particularly in early, precise screening. Summary of the Invention

[0009] This invention provides an interventional radiofrequency coil and its usage method to address the shortcomings of existing surface coils in magnetic resonance imaging of deep organs or lesions, which suffer from decreased signal-to-noise ratio, poor image quality, and easy missed or misdiagnosis due to the distance from the target tissue and the reduction of the fill factor. This invention achieves high signal-to-noise ratio and high resolution deep tissue magnetic resonance imaging, and improves the detection sensitivity and diagnostic accuracy of early small lesions.

[0010] This invention provides an interventional radiofrequency coil, comprising: a multi-lumen catheter having a wiring channel, an inner balloon channel, an outer balloon channel, and an endoscope channel therein; an inner balloon disposed on the surface of the multi-lumen catheter, the inner balloon communicating with the inner balloon channel, the inflation state of the inner balloon being adjusted through the inner balloon channel; a coil body disposed on the outer surface of the inner balloon, the shape of the coil body being adjustable by inflating or deflating the inner balloon, the wiring of the coil body being led out through the wiring channel; and an outer balloon disposed on the surface of the multi-lumen catheter, located outside the inner balloon and the coil body; the inflation state of the outer balloon being adjustable through the outer balloon channel, wherein: when deflating, the outer balloon tightly holds the coil body; when inflating, the outer balloon can expand surrounding tissue to separate the coil body from the tissue.

[0011] According to one embodiment of the present invention, the multi-lumen catheter is provided with multiple partitions, which divide the space inside the multi-lumen catheter into multiple independent cavities.

[0012] According to one embodiment of the present invention, the multi-lumen catheter includes: an outer tube; an inner tube disposed within the outer tube, forming an annular cavity between the inner tube and the outer tube, wherein the inner tube forms the endoscope channel; and a plurality of partitions disposed in the annular cavity and supported and connected between the outer tube and the inner tube, thereby dividing the annular cavity into a plurality of fan-shaped cavities for use as the wiring channel, the inner capsule channel, and the outer capsule channel.

[0013] According to one embodiment of the present invention, the end of the inner tube is configured as an endoscope outlet, and the endoscope outlet is located at the distal end of the multi-lumen catheter.

[0014] According to one embodiment of the present invention, a proximal control assembly is included, the proximal control assembly comprising: an endoscope inlet communicating with the proximal end of the endoscope channel for allowing a fiber optic endoscope, guidewire, or balloon stent to enter the endoscope channel; an inner balloon filling port communicating with the proximal end of the inner balloon channel for connecting an filling device; an outer balloon filling port communicating with the proximal end of the outer balloon channel for connecting an filling device; and a line port communicating with the proximal end of the line channel for leading out the coil line of the coil body.

[0015] According to one embodiment of the present invention, the proximal manipulation assembly further includes: a plurality of independent tube structures for respectively providing the endoscope inlet, the inner capsule filling port, the outer capsule filling port and the line port at the proximal end; a fan-shaped branch section, wherein the plurality of independent tube structures are integrated in the fan-shaped branch section, and the proximal tube segments of the plurality of independent tube structures are branched in a fan-shaped manner through the fan-shaped branch section.

[0016] The present invention also provides a method for using an interventional radiofrequency coil to control the interventional radiofrequency coil of the above embodiments. The method includes: inserting the interventional radiofrequency coil into a target cavity; first inflating the outer balloon to make it fully fit the inner wall of the cavity; then inflating the inner balloon to expand the coil body; and finally withdrawing it from the target cavity.

[0017] According to one embodiment of the present invention, the step of inserting the interventional radio frequency coil into the target cavity includes: inserting a fiber optic endoscope through an endoscope channel into the distal end of a multi-lumen catheter; and then inserting the multi-lumen catheter with the fiber optic endoscope into the target cavity under the guidance of the fiber optic endoscope.

[0018] According to one embodiment of the present invention, before the step of inserting the interventional radiofrequency coil into the target cavity, the method further includes: negative pressure aspiration of the inner balloon and the outer balloon to keep the outer diameter of the multi-lumen catheter to a minimum; the step of withdrawing the coil from the target cavity after completion includes: first negative pressure aspiration of the inner balloon to completely retract the coil body, and then negative pressure aspiration of the outer balloon to cover the outside of the coil body.

[0019] This invention provides an interventional radiofrequency coil and its usage method. By integrating the radiofrequency coil into a multi-lumen catheter structure that can be inserted into a body cavity, and designing a double-layer balloon system, the coil can deploy and operate stably near the target tissue. The coil body is located on the outer surface of the inner balloon. The inflation state of the inner balloon is controlled through the inner balloon channel, thereby adjusting the deployment shape of the coil body to ensure optimal spatial matching with the target area. The outer balloon is located outside the coil body, and its inflation and deflation are controlled through the outer balloon channel. When the outer balloon deflates, it tightly holds the coil body, achieving a coiled state, facilitating catheter insertion and positioning within the body. When the outer balloon inflates, it expands the surrounding tissue, effectively separating the coil body from surrounding interfering tissues, reducing signal attenuation and noise interference, while avoiding motion artifacts and improving imaging stability. In addition, an endoscopic channel is provided in the multi-lumen catheter, which is compatible with endoscopic imaging systems, enabling fusion guidance of MRI and optical imaging, further improving positioning accuracy. Through the above-described method, the present invention directly delivers the radio frequency receiving coil to the vicinity of the target organ, significantly shortening the distance between the coil and the lesion, greatly improving the fill factor and signal receiving sensitivity, thereby obtaining high-quality magnetic resonance images. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of the interventional radio frequency coil provided by the present invention.

[0022] Figure 2 This is a schematic diagram of the cross-sectional structure of the multi-lumen catheter with an interventional radiofrequency coil provided by the present invention.

[0023] Figure 3 This is a flowchart illustrating the method of using the interventional radio frequency coil provided by the present invention.

[0024] Figure label:

[0025] 10. Multilumen catheter; 11. Circuit channel; 12. Inner balloon channel; 13. Outer balloon channel; 14. Endoscope channel; 15. Septum; 16. Outer tube; 17. Inner tube; 18. Endoscope exit; 21. Inner balloon; 22. Coil body; 23. Outer balloon; 31. Endoscope inlet; 32. Inner balloon filling port; 33. Outer balloon filling port; 34. Circuit port; 35. Fan-shaped branch section. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0027] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. It should also be noted that in the description of the present invention, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0028] The following is combined with Figures 1-3 This invention describes specific embodiments of the interventional radio frequency coil and its usage method.

[0029] like Figure 1 and Figure 2As shown, the present invention provides an interventional radiofrequency coil, comprising: a multi-lumen catheter 10, which has a wiring channel 11, an inner balloon channel 12, an outer balloon channel 13, and an endoscope channel 14 therein; an inner balloon 21 disposed on the surface of the multi-lumen catheter 10, the inner balloon 21 being connected to the inner balloon channel 12, and the inflation state of the inner balloon 21 being adjusted through the inner balloon channel 12; a coil body 22 disposed on the outer surface of the inner balloon 21, the shape of the coil body 22 being adjustable by inflating or deflating the inner balloon 21, the wiring of the coil body 22 being led out through the wiring channel 11; and an outer balloon 23 disposed on the surface of the multi-lumen catheter 10, located outside the inner balloon 21 and the coil body 22; the inflation state of the outer balloon 23 being adjustable through the outer balloon channel 13, wherein: when deflating, the outer balloon 23 tightly holds the coil body 22; when inflating, the outer balloon 23 can expand the surrounding tissue to separate the coil body 22 from the tissue. Specifically, this technical solution achieves controllable deployment and precise positioning of the radiofrequency coil within the body through a mechanically adjustable double-balloon structure. The inner balloon 21, serving as the coil carrier, can change the geometry of the coil body 22 when inflated, expanding it from a constricted state into a ring-shaped or cylindrical receiving surface that conforms to the inner wall of the target cavity, thereby maximizing the signal receiving area and improving coupling efficiency with the target tissue. The outer balloon 23 serves multiple functions, including protection, isolation, and tissue expansion. In the depressurized state, it tightly wraps around the coil body 22, reducing frictional resistance during intervention and facilitating catheter insertion into the body via natural cavities or minimally invasive approaches. In the inflated state, the outer balloon 23 expands outward, gently expanding surrounding tissues (such as the intestinal wall and stomach wall), physically separating the coil body 22 from dynamically moving tissues or gas / liquid cavities, effectively reducing motion artifacts, magnetic susceptibility artifacts, and signal attenuation, and significantly improving the signal-to-noise ratio and spatial resolution of magnetic resonance images.

[0030] In practical applications, this interventional radiofrequency coil can be guided through natural cavities such as the mouth, anus, or vagina via endoscopy or catheter to enter the target area, such as the stomach, rectum, or uterus. After locating near the lesion, contrast agent or saline is first injected through the inner balloon channel 12 to inflate the inner balloon 21, causing the coil body 22 on the surface to unfold into a preset shape (such as a ring array) to achieve high-sensitivity signal reception. Subsequently, fluid is injected through the outer balloon channel 13 to inflate the outer balloon 23, isolating the coil body 22 from tissue displacement caused by peristalsis of the digestive tract wall or respiratory movements, forming a stable imaging environment. At the same time, a miniature camera or optical probe can be inserted into the endoscope channel 14 to achieve real-time visual guidance, ensuring that the coil is accurately located in the lesion area. Combined with MRI scans, high-contrast, high-resolution local images can be obtained, which is especially suitable for the accurate detection and evaluation of small lesions such as early tumors and submucosal lesions.

[0031] On the other hand, this interventional radiofrequency coil can also be guided via fiber optic endoscope or catheter through blood vessels into internal organs or blood vessels such as the heart, lungs, liver, kidneys, and brain. After locating near the lesion, contrast agent or saline is first injected through the inner balloon channel 12 to inflate the inner balloon 21, causing the coil body 22 on the surface to unfold into a preset shape (such as a ring array) to achieve high-sensitivity signal reception. Subsequently, fluid is injected through the outer balloon channel 13 to inflate the outer balloon 23, isolating the coil body 22 from the surrounding tissue displacement and forming a stable imaging environment. At the same time, a miniature camera or optical probe can be inserted into the endoscope channel 14 to achieve real-time visual guidance, ensuring that the coil is accurately located in the lesion area. Combined with MRI scans, high-contrast, high-resolution local images can be obtained. It is especially suitable for areas that cannot be reached by conventional MRI, such as vascular stenosis and valvular stenosis.

[0032] Furthermore, in the aforementioned interventional radiofrequency coil, the coil body 22 can be manufactured using flexible printed circuit (FPC) technology, forming a multi-turn annular, helical, or phased array structure from copper foil or superconducting materials. This structure possesses excellent flexibility and radiofrequency response characteristics, allowing it to expand conformally to the shape of the inner balloon 21 without breakage or detuning during inflation. The multi-lumen catheter 10 is made of biocompatible polymer materials, such as polyurethane, silicone, or nylon, with each channel independently isolated to ensure that fluid control and signal transmission do not interfere with each other. The inner balloon 21 and outer balloon 23 are preferably made of highly compliant materials (such as thin-walled silicone or elastic polyurethane), possessing good fit and deformation capabilities. They can conform to the geometry of different anatomical cavities (such as curved intestines, irregular uterine cavities, etc.), closely adhering to the inner wall of the lumen when inflated, improving the coupling efficiency between the coil and tissue, and reducing the risk of local compression. Simultaneously, highly compliant materials can achieve uniform expansion at lower pressures, which helps protect fragile diseased tissues, improving patient comfort and operational safety. Furthermore, the circuit channel 11 preferably includes a shielded coaxial cable or differential transmission line for connecting the coil body 22 to the external MRI system. It can also integrate impedance matching circuitry and passive / active decoupling circuitry to prevent thermal damage to tissues caused by radio frequency interference and energy coupling. The outer diameter of the external balloon 23 in its inflated state can be designed according to different anatomical locations (e.g., 3–5 cm for the rectum, 2–4 cm for the stomach) to adapt to the physiological structure of different cavities and achieve personalized imaging needs.

[0033] According to an interventional radio frequency coil of the present invention, a multi-lumen catheter 10 is provided with multiple partitions 15, which divide the space inside the multi-lumen catheter 10 into multiple independent cavities. Specifically, the partitions 15 extend along the axial direction of the multi-lumen catheter 10 and are fixedly connected to the inner wall of the catheter, dividing the originally continuous internal space into several functionally independent channels, such as a wiring channel 11, an inner balloon channel 12, an outer balloon channel 13, and an endoscope channel 14. This not only achieves a high degree of integration of signal transmission, fluid delivery, and optical observation functions, but also isolates the cavities from each other, effectively preventing cross-contamination of media, fluid leakage interfering with wiring, or obstruction of the endoscope's field of vision, ensuring the safety and reliability of the interventional process. At the same time, the partition structure enhances the overall mechanical strength of the multi-lumen catheter 10, keeping the cavities unobstructed during bending or advancement, avoiding channel closure due to compression, and ensuring stable transmission of radio frequency signals and normal balloon inflation and deflation.

[0034] Further, according to an interventional radiofrequency coil of the present invention, the multi-lumen catheter 10 includes: an outer tube 16; an inner tube 17 disposed within the outer tube 16, forming an annular cavity between the inner tube 17 and the outer tube 16, and an endoscope channel 14 formed within the inner tube 17; and multiple partitions 15 disposed within the annular cavity and supported and connected between the outer tube 16 and the inner tube 17, thereby dividing the annular cavity into multiple fan-shaped cavities for use as a wiring channel 11, an inner balloon channel 12, and an outer balloon channel 13. This concentric double-layer tube structure forms a multi-lumen layout through the annular region between the inner tube 17 and the outer tube 16, wherein the inner tube 17 serves as an independent endoscope channel 14, allowing free insertion and sliding of an endoscope or fiber optic probe, achieving full-process visual guidance; while the annular cavity is divided into several fan-shaped sub-cavities by multiple radially arranged partitions 15, which are respectively used to accommodate the coil lead (wiring channel 11), the inner balloon 21 for fluid injection (inner balloon channel 12), and the outer balloon 23 for fluid injection (outer balloon channel 13). The partition 15 not only serves as a functional divider, but also acts as a structural support, maintaining the concentricity between the inner and outer tubes 16 and the stability of the cavity, preventing the conduit from collapsing or deforming when bent.

[0035] Furthermore, in a preferred embodiment of the interventional radio frequency coil according to the present invention, the cross-sectional area of ​​the circuit channel 11 can be set to be larger than that of the inner bladder channel 12 and the outer bladder channel 13, respectively. Since the circuit channel 11 needs to accommodate multiple shielded wires, coaxial cables, or flexible circuit strips, and requires low resistance and low inductance to reduce radio frequency signal loss, its larger cross-sectional area can meet the requirements of wiring space and electromagnetic performance. The inner bladder channel 12 and the outer bladder channel 13 are mainly used for conveying liquids (such as saline or contrast agents), requiring smaller flow rates, and can complete balloon inflation at lower flow rates; therefore, their channel sizes can be relatively smaller. A larger circuit channel 11 helps reduce stress concentration of the wires during catheter bending, preventing breakage or poor contact, and improving the durability of the device and the stability of signal transmission. In addition, by optimizing the area ratio of each sector cavity, maximizing the wiring space while ensuring unobstructed fluid flow helps improve the integration and overall performance of the radio frequency coil. It is understood that the cross-sectional area of ​​the aforementioned channels can also be adaptively adjusted according to actual needs.

[0036] Furthermore, according to an interventional radiofrequency coil of the present invention, the end of the inner tube 17 is configured as an endoscope outlet 18, which is located at the distal end of the multi-lumen catheter 10. The endoscope outlet 18 is located at the very tip of the catheter, directly facing the target tissue, allowing the endoscope probe to extend from the inner tube 17 and directly observe the anterior anatomical structures, thus achieving real-time visual guidance for coil positioning. During operation, the interventional catheter can be pushed to the vicinity of the target area first, followed by the extension of the endoscope. The location of the lesion and its surrounding environment are confirmed through the front-end camera, and the catheter position is then precisely adjusted so that the coil body 22 is directly facing the lesion area. This design supports collaborative navigation of MRI and optical imaging, significantly improving positioning accuracy and avoiding mispositioning due to anatomical variations or cavity curvature. Simultaneously, a transparent protective cover or flushing hole can also be provided around the endoscope outlet 18 to prevent blood, mucus, etc., from obstructing the lens and ensuring a clear field of view.

[0037] According to the present invention, an interventional radiofrequency coil includes a proximal control assembly, comprising: an endoscope inlet 31, connected to the proximal end of an endoscope channel 14, for allowing a fiber optic endoscope, guidewire, or balloon stent to enter the endoscope channel 14; an inner balloon inflation port 32, connected to the proximal end of an inner balloon channel 12, for connecting an inflation device; an outer balloon inflation port 33, connected to the proximal end of an outer balloon channel 13, for connecting an inflation device; and a wiring port 34, connected to the proximal end of a wiring channel 11, for leading out the coil wiring of the coil body 22. Specifically, this proximal control assembly serves as a human-machine interface, integrating access ports for optical, fluid, and electrical signal functional channels, facilitating independent and precise control of each subsystem by clinical operators during intervention. A miniature endoscope can be inserted through the endoscope inlet 31 to achieve real-time intracavitary imaging and assist in positioning. The inner and outer balloons 23 can be independently inflated or depressurized through the inner balloon inflation port 32 and the outer balloon inflation port 33, achieving stepwise control of coil deployment and tissue isolation. Line port 34 ensures that radio frequency signals are transmitted to the MRI system through a low-noise transmission path. The entire control assembly is made of medical-grade insulating materials, possessing excellent biocompatibility and electromagnetic compatibility, making it suitable for safe operation in clinical MRI environments.

[0038] Furthermore, according to an interventional radiofrequency coil of the present invention, the proximal control assembly further includes: multiple independent tube structures for respectively providing an endoscope inlet 31, an inner sac filling port 32, an outer sac filling port 33, and a line port 34 at the proximal end; and a fan-shaped branch section 35, in which the multiple independent tube structures are integrated and arranged, and the proximal tube segments of the multiple independent tube structures are branched in a fan-shaped manner through the fan-shaped branch section 35. The fan-shaped branch section 35 functionally decouples the annular lumen structure at the distal end of the multi-lumen catheter 10, causing the multiple channels that were originally parallel in the catheter to expand radially in a fan shape at the proximal end, correspondingly connecting to their respective independent tube structures. This "from combined to separate" transition design ensures that each channel is completely independent at the proximal end, avoiding cross-interference during operation. For example, injecting fluid will not affect the line interface, and inserting or removing the endoscope will not compress the filling line. The fan-shaped branching layout not only facilitates medical personnel in identifying and connecting different functional ports, but also reduces the risk of tube entanglement, improving operational convenience and on-site management efficiency. Each independent tube structure can be equipped with a standard Luer connector (such as a Luer lock), fiber optic interface or RF coaxial connector to achieve quick and reliable connection with external equipment (such as endoscope main unit, pressure monitor, MRI receiver).

[0039] The present invention also provides a method for using an interventional radio frequency coil for controlling the interventional radio frequency coil of the above embodiments. The method for using the interventional radio frequency coil provided by the present invention is described below, and the method for using the interventional radio frequency coil described below can be referred to in correspondence with the interventional radio frequency coil described above. Figure 3This is a flowchart illustrating the method of using the interventional radio frequency coil provided by the present invention, as shown below. Figure 3 As shown, the method includes the following:

[0040] Step 110: Insert the interventional radiofrequency coil into the target cavity. Specifically, before the interventional procedure, ensure that both the outer balloon 23 and the inner balloon 21 are in a depressurized and contracted state to minimize the outer diameter of the catheter, facilitating safe insertion through natural cavities. Advance the radiofrequency coil along the anatomical path to the vicinity of the target area. During advancement, the anterior tissue structures can be observed in real time through the endoscopic channel 14 to ensure that the catheter travels along the correct path.

[0041] Step 120: First, inflate the outer balloon 23 to ensure it fully conforms to the inner wall of the cavity. Specifically, inject saline or contrast agent into the outer balloon channel 13 through the inflation port 33 of the proximal control component, causing the outer balloon 23 to gradually inflate. After inflation, the outer balloon 23 expands outward, gently stretching surrounding tissues (such as the intestinal wall, stomach wall, or uterine wall), isolating the coil body 22 from dynamically moving tissues and reducing motion artifacts caused by respiration and peristalsis. It also forms a physical barrier, reducing local magnetic field inhomogeneity caused by differences in magnetic susceptibility, improving image uniformity, and fixing the catheter position to prevent coil displacement during imaging, ensuring the stability of the imaging area. The highly compliant material of the outer balloon 23 allows it to conform to the irregular inner wall of the cavity, improving positioning stability and patient comfort.

[0042] Step 130: Re-inflate the inner balloon 21 and expand the coil body 22. Specifically, after the outer balloon 23 completes positioning and tissue expansion, fluid is injected into the inner balloon channel 12 through the inner balloon inflation port 32, causing the inner balloon 21 to expand. The expansion of the inner balloon 21 causes the coil body 22 on its outer surface to unfold from a contracted state to a preset geometric shape (such as a ring or cylindrical array), making it closely adhere to or adjacent to the target lesion tissue. After the coil is unfolded, the distance between it and the target tissue is significantly shortened, and the fill factor is greatly increased, thereby significantly enhancing the receiving sensitivity and signal-to-noise ratio of the magnetic resonance signal.

[0043] Step 140: After completion, withdraw the device from the target cavity. Specifically, after completing the MRI scan, the interventional device must be safely withdrawn. This can be achieved through a step-by-step decompression procedure: first, apply negative pressure to the inner balloon 21 to cause it to contract, causing the coil body 22 to retract and adhere to the catheter surface; then, aspirate the outer balloon 23 to completely collapse it and cover the outside of the coil body 22, restoring the catheter to its minimum outer diameter. Subsequently, under endoscopic guidance or external imaging monitoring, slowly withdraw the catheter to avoid scratching or damaging the cavity tissue.

[0044] Furthermore, according to a method of using an interventional radiofrequency coil according to the present invention, the step of inserting the interventional radiofrequency coil into the target cavity includes:

[0045] Step 111: Insert the fiber optic endoscope through the endoscope channel 14 into the distal end of the multi-lumen catheter 10. Specifically, insert the fiber optic endoscope or miniature camera probe into the endoscope channel 14 through the proximal endoscope inlet 31, and push it along the inner tube 17 to the distal end of the catheter, so that the lens extends from the endoscope outlet 18. Activate the light source and imaging system to provide real-time optical guidance for subsequent interventions.

[0046] Step 112: Then, the multi-lumen catheter 10 with a fiber optic endoscope is inserted into the target cavity under the guidance of the fiber optic endoscope. Specifically, the operator observes the anterior anatomical structures through real-time endoscopic imaging, controls the catheter to slowly advance along the central axis of the cavity, avoiding narrow, tortuous, or diseased areas, and precisely navigates to the target imaging site (such as the gastric antrum, rectal tumor area, or endometrial lesion area). This optical-MRI fusion guidance method significantly improves positioning accuracy and reduces the risk of blind operation, and is especially suitable for cases with complex anatomical structures or pathological deformities.

[0047] Furthermore, according to a method of using an interventional radiofrequency coil according to the present invention, the method further includes, prior to the step of inserting the interventional radiofrequency coil into the target cavity:

[0048] Step 101: Negative pressure aspiration of the inner balloon 21 and outer balloon 23 minimizes the outer diameter of the multi-lumen catheter 10. Specifically, before intervention, a negative pressure device (such as a syringe aspiration) is connected to the outer balloon filling port 33 and the inner balloon filling port 32 respectively to completely expel any residual liquid or gas from the inner balloon 21 and outer balloon 23, ensuring that the two balloons fit tightly against the catheter surface. This operation ensures that the catheter is in its thinnest and most flexible state, significantly reducing frictional resistance and the risk of tissue damage during insertion, and improving the safety and success rate of the interventional procedure.

[0049] In addition, the steps for withdrawing from the target cavity after completion include:

[0050] Step 141: First, aspirate the inner balloon 21 under negative pressure to completely retract the coil body 22. Specifically, after the scan is completed, first connect the negative pressure source through the inner balloon inflation port 32 to extract the filling fluid from the inner balloon 21, causing it to collapse completely. As the inner balloon 21 contracts, the coil body 22 attached to its surface retracts and adheres to the outer wall of the catheter.

[0051] Step 142: Aspirate the outer balloon 23 again under negative pressure, allowing it to cover the outside of the coil body 22. Specifically, after the inner balloon 21 is completely depressurized, continue aspiration under negative pressure through the outer balloon inflation port 33, causing the outer balloon 23 to further contract and tightly cover the outside of the retrieved coil body 22, forming a smooth, low-friction outer surface. This dual contraction mechanism ensures the catheter returns to its initial minimum outer diameter, enabling a safe and smooth withdrawal procedure, reducing mechanical stimulation and damage to the lumen mucosa, and improving patient tolerance.

[0052] According to the interventional radiofrequency coil and its usage method provided by the present invention, the diameter of the intracavitary radiofrequency coil is dynamically adjustable for the first time through a dual-balloon coordinated control mechanism. This allows for flexible expansion or contraction of the coil body 22 based on the anatomical dimensions of the target cavity (such as the stomach, rectum, uterus, etc.), ensuring close contact with tissue walls of different diameters. This significantly improves the filling factor and signal reception efficiency, resulting in high signal-to-noise ratio and high-resolution local magnetic resonance images, and significantly improving imaging clarity and stability. Simultaneously, the multi-lumen catheter 10 integrates the circuit channel 11, the inner balloon channel 12, the outer balloon channel 13, and the endoscope channel 14, supporting not only radiofrequency signal reception but also simultaneous balloon dilation, drug / contrast agent injection, endoscopic observation, or guidewire guidance, expanding the clinical application range of traditional radiofrequency coils. Furthermore, this device can be minimally invasively introduced via the endoscopic forceps channel or independently inserted into the target location along the guidewire, adapting to various interventional pathways. Its flexible operation and precise positioning enhance the convenience and adaptability of clinical use. Based on the above technical features, the problems of low sensitivity and susceptibility to interference in imaging deep cavitary tissues by existing surface coils have been solved, providing an innovative intracavitary magnetic resonance imaging solution for the accurate diagnosis of early lesions.

[0053] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "method," "specific method," or "some methods," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or method is included in at least one embodiment or method of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or method. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or methods. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or methods described in this specification, as well as the features of different embodiments or methods.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An interventional radio frequency coil, characterized in that, include: A multi-lumen catheter (10) has a wiring channel (11), an inner sac channel (12), an outer sac channel (13), and an endoscope channel (14). An inner balloon (21) is disposed on the surface of the multi-lumen catheter (10). The inner balloon (21) is connected to the inner balloon channel (12). The inflation state of the inner balloon (21) is adjusted through the inner balloon channel (12). The coil body (22) is disposed on the outer surface of the inner balloon (21). The shape of the coil body (22) can be adjusted by inflating or deflating the inner balloon (21). The wires of the coil body (22) are led out through the wire channel (11). An external balloon (23) is disposed on the surface of the multi-lumen catheter (10) and located outside the internal balloon (21) and the coil body (22); The inflation state of the external balloon (23) can be adjusted through the external balloon channel (13), wherein: The outer balloon (23) grips the coil body (22) when the pressure is released; When inflated, the external balloon (23) can expand the surrounding tissue to separate the coil body (22) from the tissue; The multi-lumen catheter (10) is provided with multiple partitions (15); The multi-lumen catheter (10) includes: an outer tube (16); an inner tube (17) disposed inside the outer tube (16) and forming an annular cavity between the inner tube (16); and a plurality of partitions (15) disposed in the annular cavity and supported and connected between the outer tube (16) and the inner tube (17) to divide the annular cavity into a plurality of sector cavities.

2. The interventional radio frequency coil according to claim 1, characterized in that, The endoscope channel (14) is formed inside the inner tube (17); the plurality of the fan-shaped cavities are used as the circuit channel (11), the inner capsule channel (12) and the outer capsule channel (13).

3. The interventional radio frequency coil according to claim 2, characterized in that, The end of the inner tube (17) is configured as an endoscope outlet (18), which is located at the distal end of the multi-lumen catheter (10).

4. The interventional radio frequency coil according to any one of claims 1 to 3, characterized in that, Includes a proximal control component, the proximal control component comprising: Endoscope inlet (31) connects to the proximal end of the endoscope channel (14) and is used to allow a fiber optic endoscope, guidewire or balloon stent to enter the endoscope channel (14). The inner capsule filling port (32) is connected to the proximal end of the inner capsule channel (12) and is used to connect the filling device; The outer capsule filling port (33) is connected to the proximal end of the outer capsule channel (13) and is used to connect the filling device; Line port (34) connects to the near end of the line channel (11) and is used to lead out the coil line of the coil body (22).

5. The interventional radio frequency coil according to claim 4, characterized in that, The proximal manipulation component also includes: Multiple independent tube structures are used to respectively set the endoscope inlet (31), the inner capsule filling port (32), the outer capsule filling port (33) and the line port (34) at the proximal end. A fan-shaped branch section (35) is provided, in which multiple independent pipe structures are integrated and arranged, and the proximal pipe sections of the multiple independent pipe structures are bifurcated in a fan-shaped manner through the fan-shaped branch section (35).

6. A method of using an interventional radio frequency coil, characterized in that, The method for manipulating the interventional radio frequency coil as described in any one of claims 1 to 5 includes: Insert the interventional radiofrequency coil into the target cavity; First, inflate the external balloon (23) to make it fully conform to the inner wall of the cavity; Refill the inner balloon (21) and expand the coil body (22). After completion, withdraw from the target cavity.

7. The method of using the interventional radio frequency coil according to claim 6, characterized in that, The step of inserting the interventional radiofrequency coil into the target cavity includes: The fiber optic endoscope is inserted into the distal end of the multi-lumen catheter (10) through the endoscope channel (14); Then the multi-lumen catheter (10) with the fiber optic endoscope is inserted into the target cavity under the guidance of the fiber optic endoscope.

8. The method of using the interventional radio frequency coil according to claim 6, characterized in that, Prior to the step of inserting the interventional radiofrequency coil into the target cavity, the procedure further includes: negative pressure aspiration of the inner balloon (21) and the outer balloon (23) to keep the outer diameter of the multi-lumen catheter (10) to a minimum; The steps of withdrawing the target cavity after completion include: firstly, negative pressure suction of the inner balloon (21) to completely retract the coil body (22), and then negative pressure suction of the outer balloon (23) to cover the outside of the coil body (22).

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