Semi-open birdcage mammary gland intervention coil

Abstract

The utility model discloses a semi-open birdcage mammary gland intervention coil, including a plurality of cage legs, a pair of semi-open end rings arranged in parallel at intervals, and a shielding layer, the plurality of cage legs are arranged between the pair of semi-open end rings at intervals to form a semi-open birdcage coil main body, and each semi-open end ring is closed through a top frame. The two ends of the coil form an open structure and are used for magnetic resonance guided mammary gland interventional operation, the shielding layer integrally extends outside the semi-open birdcage structure and is used for gathering a magnetic field and improving the magnetic field intensity in an imaging area, and a top opening of a semi-open birdcage coil body is used for prostrate mammary gland tissue to enter. The semi-open birdcage mammary gland intervention coil is simple in circuit and convenient to debug, complex decoupling and debugging work faced by a multi-channel coil is reduced, and the semi-open birdcage mammary gland intervention coil belongs to a new structure of a mammary gland intervention coil.

Description

Technical Field

[0001] The utility model relates to the field of magnetic resonance equipment, in particular to a semi-open birdcage breast intervention coil. Background Art

[0002] Magnetic resonance image-guided breast interventional surgery can effectively achieve the effects of standard surgery and reduce complications. Because it requires good resolution and soft tissue contrast, it is mostly performed in a high-field strength MR system of 1.5T or above, configured with a dedicated open coil and performed in a closed magnet.

[0003] The open interventional coil is the core component of magnetic resonance-guided breast interventional surgery. It needs to have both structural openness and operability, and ensure excellent magnetic resonance image quality.

[0004] Currently, most magnetic resonance breast interventional coils are open on both sides to facilitate interventional operations. Multiple annular coils are arranged on a semi-cylindrical support surface to form a coil array to image the breast tissue in the area.

[0005] The advantages of the coil array are simple structure, large number of channels, high sensitivity, and strong imaging signal-to-noise ratio. However, due to the imaging depth limitation of the surface coil, it has a greater impact on the uniformity of large-size imaging areas. At the same time, the coupling between multiple channels requires repeated adjustment of the positions of adjacent coils during production and debugging, and the addition of additional circuits to decouple the adjacent coils.

[0006] The production and debugging technology of array breast interventional coils is high, the decoupling workload is large, the circuit structure is complex, and the performance of each channel must be highly stable with the deviation as small as possible, otherwise it will significantly affect the uniformity of the magnetic resonance image and reduce the image quality.

[0007] Aiming at the problems of array coil, such as high difficulty in development technology, complex decoupling circuit and uniformity, a semi-open birdcage breast interventional coil was proposed. Utility Model Content

[0008] The utility model aims to provide a semi-open birdcage breast intervention coil for data collection of breast intervention magnetic resonance images.

[0009] To this end, the utility model provides a semi-open birdcage breast interventional coil, comprising a plurality of cage legs, a pair of semi-open-end rings arranged in parallel and at intervals, and a shielding layer, wherein the plurality of cage legs are arranged between the pair of semi-open-end rings and at intervals to form a semi-open birdcage coil body, each of the semi-open-end rings is closed by a top frame, and both ends of the coil form an open structure for magnetic resonance-guided breast interventional surgery operations, the shielding layer extends as a whole outside the semi-open birdcage structure for gathering the magnetic field and increasing the magnetic field strength in the imaging area, and the top opening of the semi-open birdcage coil body is used for the entry of breast tissue in a prone position.

[0010] Furthermore, between any two adjacent cage legs, a capacitive element in the resonant circuit is connected, and the capacitive element is distributed on a semi-open-end ring.

[0011] Furthermore, the above-mentioned interventional coil is excited through a single port, wherein the excitation port is arranged on one of the semi-open-end rings.

[0012] Furthermore, the above-mentioned half-open-end ring includes a semicircular ring portion and left and right top surface folded edges connected to the semicircular ring portion, wherein the top frame is connected and closed with the left and right top surface folded edges.

[0013] Furthermore, the shielding layer is a pure copper shielding layer, and an insulating isolation layer is provided between the pure copper shielding layer and the semi-open birdcage coil body.

[0014] The semi-open birdcage coil of this utility model is evolved from the traditional birdcage coil. Both ends are open and equipped with tissue fixation devices. It is suitable for breast intervention surgery in the prone position. It uses a single port for excitation and does not need to consider channel coupling. At the same time, the coil is close to the tissue, and the magnetic field in the middle area is evenly distributed, so excellent magnetic resonance images can be obtained.

[0015] The utility model verifies the magnetic field distribution of the semi-open birdcage breast interventional coil through CST field circuit joint simulation. The interventional coil has high openness, and the structure with open ends of the coil allows doctors to perform interventional surgery from the side. The single-channel circuit structure is simple and easy to debug, which reduces the complex decoupling and debugging work faced by multi-channel coils. It is a new configuration of breast interventional coil.

[0016] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0018] Figure 1 This is a schematic diagram of the application of semi-open birdcage breast interventional coil Figure 1 ;

[0019] Figure 2 This is a schematic diagram of the application of semi-open birdcage breast interventional coil Figure 2 ;

[0020] Figure 3 This is the structural diagram of the semi-open birdcage breast interventional coil;

[0021] Figure 4 The top view structure of the semi-open birdcage interventional coil body is shown;

[0022] Figure 5 This is a top view of the semi-open birdcage breast intervention coil simulation model;

[0023] Figure 6 This is the side view of the semi-open birdcage breast intervention coil simulation model;

[0024] Figure 7 It is the simulated magnetic field direction diagram of the semi-open birdcage breast intervention coil;

[0025] Figure 8 This is the simulated magnetic field distribution diagram of the semi-open birdcage breast interventional coil. DETAILED DESCRIPTION

[0026] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0027] Cage coils are widely used in MRI, mainly due to the high uniformity of the radio frequency magnetic field (B1) it generates and the coaxiality of the radio frequency coil and the main magnetic field. They are currently the most popular body coils for clinical magnetic resonance imaging and can generate uniform circularly polarized electromagnetic fields.

[0028] The semi-open birdcage coil of the utility model is an improvement on the traditional birdcage structure. It utilizes the uniform radio frequency magnetic field characteristics of the cage coil and adopts half of the birdcage structure to form a semi-open structure. The semi-open structure fits the breast tissue of the human body and is open on both sides for easy interventional surgery.

[0029] Both ends are open and equipped with tissue fixation devices, which are suitable for breast interventional surgery in the prone position. A single port is used for excitation, and there is no need to consider channel coupling. At the same time, the coil is close to the tissue, and the magnetic field in the middle area is evenly distributed, so excellent magnetic resonance images can be obtained.

[0030] In view of the technical difficulties such as complex circuits, difficult decoupling, and long debugging time of multi-channel array coils, the semi-open birdcage intervention coil uses single-channel excitation, does not require complex circuit operations such as decoupling, and has a simple circuit structure. At the same time, the birdcage coil has a relatively mature theoretical basis and engineering application practice, and the parameter design and debugging of the semi-open birdcage coil can refer to the birdcage coil.

[0031] This coil is designed for magnetic resonance-guided breast interventional surgery. Figure 1 and Figure 2 The actual application scenario is shown, which shows a simulated female phantom 2. During the interventional surgery, the patient is in a prone position and the tissue is placed inside the interventional coil. Since the birdcage coil magnetic field is divergent, a shielding layer is usually required to be designed on the outside to constrain the magnetic field. For this purpose, a shielding layer 4 of a semi-open birdcage coil is provided to concentrate the magnetic field, increase the magnetic field strength in the region of interest (imaging area), and reduce the magnetic field escape. The semi-open birdcage interventional coil body 5 is used to receive magnetic resonance signals for tissue imaging. The detailed structure is shown in FIG. Figure 3 and Figure 4 shown.

[0032] Figure 3 and Figure 4 It is based on an 11-leg birdcage coil, and one of the legs is pulled apart to form a semi-open structure. The number of coil legs here can be adjusted and determined according to design requirements. Cage leg 6 is usually made of pure copper and is equivalent to an inductor in the resonant circuit.

[0033] Figure 3 and Figure 4 The model shown is established in CST software. The discrete ports 7 are distributed on the semi-open-end ring 9. Between any two adjacent cage legs 6, a capacitive element is connected in the resonant circuit. The capacitive element is distributed on each discrete port of a semi-open-end ring and forms an LC resonant circuit with the cage legs 6. The shielding layer 4 is made of pure copper.

[0034] The half-open-end ring 9 includes a semicircular ring portion 91 and left and right top surface folded edges 92 connected to the semicircular ring portion, wherein two top frames 10 are respectively connected and closed with the left and right top surface folded edges 92 .

[0035] Figure 5 and Figure 6 This is a simulation model diagram of a semi-open birdcage breast interventional coil. A pull-out splint can be designed from the end ring direction to fix the breast tissue, making it easier for doctors to locate lesions and perform minimally invasive interventional surgery.

[0036] The electromagnetic simulation of the breast intervention coil was verified by CST Microwave Studio, and the RF magnetic field distribution at the resonant frequency of the coil was obtained as follows: Figure 7 As shown, Figure 7The figure shows the direction of the coil's RF magnetic field at various positions in space 8. Nowadays, the main magnetic field direction in superconducting magnetic resonance systems is mostly along the axis of the human body. In theory, the magnetic field direction generated by the RF coil needs to be perpendicular to the axis, and the proton offset cutting RF magnetic field can collect MR signals. It can be seen from the figure that the magnetic field direction in the area of ​​interest of the semi-open birdcage breast interventional coil proposed by the utility model is perpendicular to the surface of the interventional coil. Figure 1 That is, it penetrates the human body in the vertical direction and is perpendicular to the axial main magnetic field, meeting the design requirements.

[0037] The simulated coil RF magnetic field distribution is as follows: Figure 8 As shown, the control Figure 2 Coil structure, Figure 8 The magnetic field distribution is along the leg direction and along the radius direction respectively. Except for the location where the coil is located where the magnetic field strength is relatively high, the magnetic field distribution in the region of interest is uniform, which provides a uniform radio frequency magnetic field for breast MRI, which is beneficial to improve image resolution and enhance image quality.

[0038] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A semi-open birdcage breast interventional coil, characterized in that: It includes a plurality of cage legs, a pair of semi-open-end rings arranged in parallel and spaced apart, and a shielding layer. The plurality of cage legs are spaced apart from each other between a pair of half-open-end rings to form a semi-open birdcage coil body. Each of the half-open-end rings is closed by a top frame, and both ends of the coil form an open structure for magnetic resonance-guided breast interventional surgery. The shielding layer extends as a whole outside the semi-open birdcage structure to concentrate the magnetic field and increase the magnetic field strength in the imaging area. The top opening of the semi-open birdcage coil body is used for the entry of breast tissue in the prone position.

2. The semi-open birdcage breast interventional coil according to claim 1, characterized in that: Between any two adjacent cage legs, a capacitive element in the resonant circuit is connected, and the capacitive element is distributed on a semi-open-end ring.

3. The semi-open birdcage breast interventional coil according to claim 1, characterized in that: The intervention coil is excited through a single port, wherein the excitation port is arranged on one of the semi-open-ended rings.

4. The semi-open birdcage breast interventional coil according to claim 1, characterized in that: The half-open-end ring includes a semicircular ring portion and left and right top surface folded edges connected to the semicircular ring portion, wherein the top frame is connected and closed with the left and right top surface folded edges.

5. The semi-open birdcage breast interventional coil according to claim 1, characterized in that: The shielding layer is a pure copper shielding layer, and an insulating isolation layer is provided between the pure copper shielding layer and the semi-open birdcage coil body.

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