Knee joint radio frequency coil and transmit-receive integrated coil assembly

Abstract

The application relates to a knee joint radio frequency coil and a transceiving integrated coil assembly. The knee joint radio frequency coil comprises a first end ring, a second end ring and a plurality of crosspiece parts arranged between the first end ring and the second end ring; wherein the crosspiece parts comprise a plurality of first crosspiece parts and a plurality of second crosspiece parts, each first crosspiece part extends linearly, and each second crosspiece part is provided with an arc-shaped protrusion to adapt to the protruding joint of a detection object. The knee joint radio frequency coil adopts a birdcage transmitting coil close to the knee joint to transmit radio frequency signals, so that signal loss is reduced, the second crosspiece part with the arc-shaped protrusion is arranged close to the knee joint, the compression and discomfort of a scanning object in a scanning process are reduced, and the scanning experience of a patient is improved.

Description

Technical Field

[0001] This application relates to the field of magnetic resonance imaging technology, and in particular to a knee joint radio frequency coil and a transceiver coil assembly. Background Technology

[0002] In knee joint scans using magnetic resonance imaging, traditional birdcage transmitting coils are used to transmit radio frequency signals. However, traditional birdcage transmitting coils typically employ a linear design, making it difficult to balance comfort and internal B1 field uniformity when scanning complex joints like the knee. Furthermore, due to the uneven thickness of the thigh and calf sides of the knee joint, the distance between the traditional birdcage transmitting coil and the knee joint varies, resulting in non-uniform B1 field within the coil and reduced transmission efficiency.

[0003] Therefore, there is an urgent need for an improved radio frequency coil design that can better adapt to the anatomy of the knee joint, improve the imaging quality of knee joint scans, and enhance patient comfort. Utility Model Content

[0004] The technical problem to be solved by this application is to provide a radio frequency coil that can improve the quality and comfort of knee joint MRI scans, addressing the shortcomings of traditional birdcage coils in the prior art.

[0005] In a first aspect, this application provides a knee joint radio frequency coil, comprising: a first end ring, a second end ring, and a plurality of crossbars, wherein the crossbars are disposed between the first end ring and the second end ring; wherein the crossbars include a plurality of first crossbars and a plurality of second crossbars, each first crossbar extending in a straight line, and each second crossbar having an arcuate protrusion to adapt to the protruding joint of the detection object.

[0006] In one embodiment, a plurality of first crossbar portions are arranged at equal intervals along the circumference of the knee joint radio frequency coil, and a plurality of second crossbar portions are arranged side by side along the circumference of the knee joint radio frequency coil.

[0007] In one embodiment, the second crossbar includes at least two sections, and the two second crossbar sections are configured with a set bending angle to adapt to the knee of the scanned object.

[0008] In one embodiment, the circumference of the first end ring is smaller than that of the second end ring, allowing the coil to adapt to the uneven thickness of the thigh and calf sides of the knee joint. Furthermore, the capacitance on each end ring is proportional to its circumference. By finely designing the ratio of capacitance values ​​between the large and small end rings, the uniformity of the longitudinal magnetic field is improved.

[0009] Secondly, this application also provides a knee joint radio frequency coil, including: a lower part, wherein the lower part includes a lower housing and a plurality of first crossbars disposed in the lower housing, and an end ring lower part connected to the plurality of first crossbars, the plurality of first crossbars being arranged sequentially along the circumference of the knee joint radio frequency coil, and each first crossbar extending along the axial direction of the knee joint radio frequency coil.

[0010] The upper part, detachably connected to the lower part, includes an upper outer shell and at least one second crossbar portion disposed in the upper outer shell, and an upper part of an end ring connected to a plurality of second crossbar portions, wherein at least a portion of the second crossbar portion is bent;

[0011] After the upper part is connected to the lower part, the multiple first crossbars, the upper part of the end ring, the multiple second crossbars, and the lower part of the end ring form a transmitting coil with protrusions.

[0012] Thirdly, this application also provides a transceiver coil assembly for magnetic resonance imaging at the knee joint. The transceiver coil assembly includes: a knee joint radio frequency coil having a first end ring, a second end ring, and a plurality of crossbars; the crossbars are disposed between the first end ring and the second end ring; wherein, the crossbars include a plurality of first crossbars and a plurality of second crossbars, each first crossbar extending in a straight line, and each second crossbar having an arc-shaped protrusion to adapt to the protruding joint of the object being detected;

[0013] A receiving coil, located inside the knee joint radio frequency coil, is composed of multiple coil units.

[0014] In one embodiment, the circumference of the first end ring is smaller than the circumference of the second end ring, and the capacitance on each end ring is proportional to its circumference.

[0015] In one embodiment, the transceiver coil assembly further includes a housing enclosing the knee joint radio frequency coil, the housing being made of a rigid material; wherein the housing has a receiving cavity whose shape is adapted to the contour of the knee joint radio frequency coil.

[0016] In one embodiment, the housing consists of an upper housing and a lower housing, which are detachably connected, and the first end ring, the second end ring, and portions of the crossbar are located in the upper housing and the lower housing, respectively.

[0017] In one embodiment, the receiving coil is fixed to the lower housing of the knee joint transmitting coil; wherein the receiving coil is a flexible coil having an opening through which the flexible coil can be wrapped around the scanning object.

[0018] The aforementioned radio frequency coil uses a knee joint radio frequency coil located close to the knee joint to transmit radio frequency signals, thereby reducing signal loss. The crossbar near the knee joint is designed to be curved, allowing the coil to conform to the curve of the knee joint, reducing pressure and discomfort during the scanning process and improving the patient's scanning experience. The aforementioned transceiver coil assembly also integrates a receiving coil within the knee joint radio frequency coil that transmits radio frequency signals, enabling the coil device to both transmit and receive signals, simplifying the operation process of magnetic resonance scanning. Attached Figure Description

[0019] Figure 1 A schematic diagram of the structure of a knee joint radio frequency coil provided in one embodiment;

[0020] Figure 2 A schematic diagram of the structure of a knee joint radio frequency coil is provided for another embodiment;

[0021] Figure 3(a) is a schematic diagram comparing the cross-sectional B1 field of a traditional birdcage coil and a knee joint radio frequency coil in one embodiment;

[0022] Figure 3(b) is a schematic diagram comparing the sagittal B1 field of a traditional birdcage coil and a knee joint radio frequency coil in one embodiment;

[0023] Figure 4 This is a B1 field curve of the sagittal plane center position of a conventional birdcage coil and a knee joint radio frequency coil in one embodiment;

[0024] Figure 5 This is a B1 field curve at the center position of the sagittal plane for different capacitance ratios of the radio frequency coil of the knee joint in one embodiment.

[0025] Figure 6 A schematic diagram of the transceiver coil assembly structure provided in one embodiment;

[0026] Figure 7 This is a schematic diagram of the housing structure of the transceiver coil assembly in one embodiment;

[0027] Figure 8 This is a cross-sectional structural diagram of a transceiver coil assembly in one embodiment;

[0028] Figure 9 This is a schematic diagram of the receiving coil in one embodiment.

[0029] Explanation of reference numerals in the attached figures:

[0030] 100. Knee joint transmitting coil; 110. First end ring; 120. Second end ring; 130. First crossbar portion; 131. Second crossbar portion;

[0031] 200. Transceiver coil assembly;

[0032] 300, Receiving coil; 320, Flexible substrate; 330, Opening;

[0033] 410. Upper outer shell; 420. Lower outer shell; 421. Plug; 422. Snap-fit; 430. Receiving cavity. Detailed Implementation

[0034] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0035] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.

[0036] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0037] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0038] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0039] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0040] In one embodiment, a knee joint radio frequency coil 100 is provided for use in magnetic resonance imaging (MRI) of the knee joint, transmitting magnetic resonance signals to the scanned object. The knee joint radio frequency coil 100 is a birdcage coil, such as... Figure 1 The diagram shows the structure of the knee joint radio frequency coil 100 in this embodiment. The knee joint radio frequency coil 100 includes a first end ring 110, a second end ring 120, and multiple crossbars connecting the two end rings. The first end ring 110 and the second end ring 120 are provided with end ring antennas, and the crossbars are provided with crossbar antennas. The first end ring 110 and the second end ring 120 are provided at both ends of the crossbars and at both ends between two adjacent crossbars, and the crossbars are respectively connected to the first end ring 110 and the second end ring 120 at their respective ends. The multiple crossbars are arranged circumferentially (preferably evenly spaced) along the knee joint radio frequency coil 100. The crossbars also include multiple first crossbars 130 and multiple second crossbars 131. Each first crossbar 130 extends linearly, and each second crossbar 131 is provided with an arc-shaped protrusion to adapt to the protruding joint of the detection object. Figure 1As shown, the second transverse section 131 is generally located above the knee joint radio frequency coil 100 and protrudes and bends in the direction away from the knee joint radio frequency coil 100. The number of second transverse sections 131 can be one or two, and their shape can be arc-shaped or angled, etc., to fit the shape of the knee joint. This curved design allows the second transverse section 131 near the knee to better fit the curved structure of the knee joint, avoiding the local pressure that may be caused by traditional straight transverse sections, which can improve the patient's scanning experience. In addition, the design of the second transverse section 131 increases the effective length, making the longitudinal magnetic field more uniform.

[0041] In one embodiment, a plurality of first crossbars 130 are arranged at equal intervals along the circumference of the knee joint radio frequency coil 100, and a plurality of second crossbars 131 are arranged side by side along the circumference of the knee joint radio frequency coil 100. Specifically, the plurality of first crossbars 130 are concentrated and spaced apart at the lower part of the knee joint radio frequency coil 100 to adapt to the shape of the posterior side of the knee joint when the scanned object is lying flat, and at least one second crossbar 131 or a plurality of second crossbars 131 are concentrated at the upper part of the knee joint radio frequency coil 100 to adapt to the shape of the knee joint of the scanned object.

[0042] In one embodiment, at least two second crossbars 131 are included, and the two second crossbars 131 are configured with a predetermined bending angle to adapt to the knee of the scanned object. The two second crossbars 131 may protrude in a direction opposite to the radial direction, and the bending angle between the two second crossbars 131 may be the same or different. The specific bending angle can be designed according to the position of the second crossbars 131, and the interval between the two second crossbars 131 may be wider than the interval between the first crossbars 130 to accommodate knee rotation. In this embodiment, multiple second crossbars 131 are used, providing more space for the knee joint and improving the comfort of the scanned object.

[0043] In another embodiment, the first end ring 110 and the second end ring 120 can be configured as elliptical shapes. This elliptical shape design better conforms to the anatomical structure of the human knee joint, improving the fit between the knee joint radio frequency coil 100 and the knee joint, making the distance from the circumference of the end ring to the human body structure more uniform, thereby achieving better signal reception. Furthermore, as... Figure 2The diagram shows a schematic of the structure of a knee joint radio frequency coil 100 in one embodiment. The circumference of the first end ring 110 of the knee joint radio frequency coil 100 can be smaller than the circumference of the second end ring 120. The circumference of the first end ring 110 corresponds to the thickness of the human calf, and the circumference of the second end ring 120 corresponds to the thickness of the human thigh, thus forming a gradually decreasing conical structure. This allows the first crossbar 130 of the non-bent part of the scanned object to fit more closely to the human knee joint. Therefore, the distance between each crossbar and the human body structure is more uniform along the axial direction of the knee joint radio frequency coil 100. Furthermore, the lower boundary of the first end ring 110 can be flush with the lower boundary of the second end ring 120. This design can fit the shape of the knee joint and leg when the scanned object is lying flat on the scanning bed.

[0044] In another embodiment, the knee joint radio frequency coil 100 includes a plurality of first crossbars 130 and a plurality of second crossbars 131. Each first crossbar 130 extends in a straight line, and each second crossbar 131 is provided with an arc-shaped protrusion to adapt to the protruding joint of the detection object. The first end ring 110 and the second end ring 120 are elliptical, and the circumference of the first end ring 110 is smaller than that of the second end ring 120. Referring to Figure 3, Figure 3(a) is a schematic diagram of the cross-sectional B1+ field of a conventional birdcage coil (left) and the knee joint radio frequency coil 100 (right) in this embodiment. It can be seen from the figure that although the cross-section of the knee joint radio frequency coil 100 is elliptical, its internal field is as uniform as that of a conventional birdcage coil and can also form circular polarization. Figure 3(b) is a schematic diagram of the sagittal B1 field of a conventional birdcage coil (left) and the knee joint radio frequency coil 100 (right) in this embodiment. As can be seen from the figure, the internal field of the knee joint radio frequency coil 100 is more uniform and stronger than that of the conventional coil, which improves the fill factor of the coil (the proportion of the scanned object to the coil volume / space), increases comfort, and enhances the signal-to-noise ratio. Figure 4 The graph shows the B1 field (RF field) curves at the center of the sagittal plane for both the traditional birdcage coil and the knee joint RF coil 100. As can be seen from the graph, with the B1 field at Z=-65 as the baseline, the B1 of the knee joint RF coil 100 decreases by 25.7% at Z=60, while the traditional birdcage coil decreases by 34.7%. At Z=130, the coverage of the knee joint RF coil 100 is exceeded, but not by the traditional birdcage coil. However, the B1 of the knee joint RF coil 100 is still 6.3% higher than that of the traditional birdcage coil, indicating that the B1 of the knee joint RF coil 100 is more uniform in the Z-axis direction.

[0045] In one embodiment, two adjacent crossbars are connected by a fixed capacitor or an adjustable capacitor. The two adjacent crossbars, together with the first end ring 110 and the second end ring 120 located between them, form a loop. Therefore, the knee joint radio frequency coil 100 includes multiple loops arranged circumferentially, and the number of loops is equal to the number of crossbars in the knee joint radio frequency coil 100. In this embodiment, the number of feed ports is equal to the number of loops, i.e., one feed port acts on one loop. Optionally, the feed ports can be located at the end. For example, in this embodiment, multiple feed ports are spaced apart circumferentially along the same end of the knee joint radio frequency coil 100, i.e., the feed ports are located on the end subunit. Each loop can be controlled to independently transmit magnetic resonance signals. Further, as... Figure 2 As shown, this embodiment can form three different loops. The first loop can be formed by the two first crossbars 130 and the partial end loop between them. The second loop can be formed by the two second crossbars 131 and the partial end loop between them. The third loop can be formed by the first crossbars 130 and the second crossbars 131 and the partial end loop between them, forming a total of six loops. Considering that there are multiple loops such as the first loop and the second loop in the knee joint radio frequency coil 100, and that the circuit perimeter of each loop is different, there will be deviations in the fixed capacitors connected between the crossbars. In this embodiment, it is preferable to configure two adjacent crossbars to be connected by an adjustable capacitor to achieve adjustment of the resonant frequency of different loops, thereby achieving precise adjustment of the resonant frequency of the knee joint radio frequency coil 100.

[0046] Specifically, the capacitors connecting the crossbars can be respectively set on the first end ring 110 and the second end ring 120. The capacitance values ​​on the first end ring 110 and the second end ring 120 can be precisely set according to the circuit circumference of the end rings and the crossbars. In order to adapt to the shape of the calf and the thigh, the circumference of the first end ring 110 located on the calf is smaller than the circumference of the second end ring 120 located on the thigh. The total capacitance set on the first end ring 110 can also be smaller than that on the second end ring 120. That is, the total capacitance value set on the first end ring 110 and the second end ring 120 is proportional to its circumference, so that the internal field of the coil is more uniform. For example, the ratio of the total capacitance value of the second end ring 120 to the first end ring 110 can be 1:1.5, 1:2.5, etc. In practice, it can be adjusted according to the ratio of the circumferences of the two end rings to ensure the symmetry and consistency of the entire resonant structure of the knee joint radio frequency coil 100, so that the current is evenly distributed and thus the internal field is uniform. Figure 5 The graphs show the field at the center of the sagittal plane (B1) of the RF coil 100 for different capacitance ratios in the knee joint, combined with... Figure 5It can be seen that, taking B1 at Z=-60 as the baseline value, the B1 ratio at Z=60 and Z=130 (outside the coverage range of the birdcage coil) is calculated respectively. As the ratio of the large and small end ring capacitance increases, B1 decreases more slowly. Even when the ratio is 1:2.5, B1 at Z=60 increases by 8%. This experiment shows that the higher the ratio of the large and small end ring capacitance, the stronger B1 at the lower leg.

[0047] This application provides a knee joint radio frequency coil 100 for use in magnetic resonance imaging (MRI) detection of the knee joint, transmitting magnetic resonance signals to the scanned object. The specific structure includes: a lower part comprising a lower housing 420 and a plurality of first crossbars 130 disposed within the lower housing, and a lower end ring connected to the plurality of first crossbars 130, the plurality of first crossbars 130 being arranged sequentially along the circumference of the knee joint radio frequency coil 100, each first crossbar 130 extending axially along the knee joint radio frequency coil 100; an upper part detachably connected to the lower part, comprising an upper housing 410 and at least one second crossbar 131 disposed within the upper housing 410, and an upper end ring connected to the plurality of second crossbars 131, wherein at least a portion of the second crossbars 131 is bent; after the upper part is connected to the lower part, the plurality of first crossbars 130, the upper end ring, the plurality of second crossbars 131, and the lower end ring form a transmitting coil with protrusions.

[0048] Specifically, to better support the leg of the scanned object and facilitate coil removal, a rigid outer shell can be used to enclose the knee joint radio frequency coil 100. This outer shell is divided into an upper outer shell 410 and a lower outer shell 420, which are detachably connected. Correspondingly, the knee joint radio frequency coil 100 is also divided into an upper and a lower part. For example... Figure 8 As shown, the upper part of the knee joint radio frequency coil 100 includes at least one second crossbar portion 131, a first crossbar portion 130, and a portion of the first end ring 110 and the second end ring 120. The upper part can also be entirely composed of the second crossbar portion 131 and a portion of the first end ring 110 and the second end ring 120. These crossbar portions are arranged circumferentially along the two end rings. The upper part of the knee joint radio frequency coil 100 is disposed within the upper housing 410. The second crossbar portion 131 is a curved crossbar antenna. The second crossbar portion 131 can also be at least partially curved away from the radial direction of the coil, and its curvature / arc is adapted to the shape of the knee joint of the scanned object. Figure 8As shown in the transmitting coil diagram, the lower part of the knee joint radio frequency coil 100 consists of first crossbars 130 arranged at equal intervals along the circumference of the coil, and another part consisting of first end rings 110 and second end rings 120. The lower part is housed within the lower housing 420. When the upper housing 410 and the lower housing 420 are connected, the upper and lower parts of the knee joint radio frequency coil 100 are connected to form a complete transmitting coil having multiple first crossbars 130, second crossbars 131, first end rings 110, and second end rings 120, which can be used for transmitting magnetic resonance signals.

[0049] This application also provides a transceiver coil assembly 200, such as Figure 6 The diagram shows the structure of the transceiver coil assembly 200. This assembly includes an RF coil and a receiving coil 300. The RF coil is a knee joint RF coil 100, having a first end ring 110 and a second end ring 120 arranged in parallel, and multiple crossbars disposed between the two end rings. These crossbars are spaced apart circumferentially along the knee joint RF coil 100 and extend axially along the coil. Each crossbar includes multiple first crossbars 130 and multiple second crossbars 131. Each first crossbar 130 extends linearly, and each second crossbar 131 has an arc-shaped protrusion to accommodate the protruding joint of the target object. The arc-shaped bend is away from the radial direction of the knee joint RF coil 100 to conform to the shape of the knee joint of the scanned object. The receiving coil 300 is formed by multiple coil units arranged in an overlapping manner. These coil units can be circular, square, etc., and their number (3, 4, etc.) is not limited and can be set according to the actual size of the covered area. The overlapping density of the coil units can also be set according to actual requirements such as signal-to-noise ratio and other imaging parameters.

[0050] Specifically, the receiving coil 300 is located inside the knee joint radio frequency coil 100. During operation, the knee joint radio frequency coil 100 transmits radio frequency signals to the scanned object, and the receiving coil 300 receives signals generated by the target tissue for image reconstruction. Because the knee joint radio frequency coil 100 employs a conformal birdcage coil structure that fits the knee joint and uses a small transmitting coil closer to the knee joint, it can generate a uniform and strong radio frequency field. The high-density receiving coil 300 is integrated inside the knee joint radio frequency coil 100, forming a transceiver coil assembly 200, achieving high-efficiency and high-sensitivity signal transmission and reception, facilitating magnetic resonance scanning and improving scanning efficiency.

[0051] In one embodiment, both the first end ring 110 and the second end ring 120 are elliptical, with the circumference of the first end ring 110 being smaller than that of the second end ring 120. The first end ring 110 is positioned on the lower leg of the scanned object, and the second end ring 120 is positioned on the thigh of the scanned object. This design makes the entire knee joint RF coil 100 have a conical structure, conforming to the shape of the human body or other objects being scanned. Furthermore, the lower boundaries of the two end rings can be aligned to better adapt to the shape of the knee joint when the scanned object is lying on the scanning bed, resulting in a higher fill factor for the coil and enhancing the signal-to-noise ratio. Further, the capacitance on each end ring is proportional to its circumference, meaning the capacitance value on the second end ring 120 is greater than that on the first end ring 110. This design ensures consistent resonant frequencies of the knee joint RF coil 100 and improves the uniformity of the RF field.

[0052] In one embodiment, Figure 7 This is a schematic diagram of the housing structure of a transceiver coil assembly 200 in this application. Figure 8 This is a schematic diagram of the cross-sectional structure of the transceiver coil assembly 200 after assembly, combined with... Figure 7 and Figure 8 As shown, the transceiver coil assembly 200 also includes a housing surrounding the knee joint radio frequency coil 100. The housing is made of a rigid material and has a receiving cavity 430. The housing can be made of a material with sufficient mechanical strength, such as engineering plastics (e.g., ABS, polycarbonate), fiber-reinforced composite materials, or metal alloys. It is preferably a non-magnetic or weakly magnetic material to avoid interference with the static magnetic field (B0 field) and radio frequency field (B1 field) of the magnetic resonance. The receiving cavity 430 is used to place the knee joint of the scanning object. The shape of the receiving cavity 430 is adapted to the contour of the knee joint radio frequency coil 100, that is, it is a hollow cylinder as a whole, and it is also curved at the rigid housing corresponding to the second crossbar 131. The shape of the receiving cavity is precisely adapted to the three-dimensional contour of the knee joint radio frequency coil 100, which can reliably accommodate and fix the first end ring 110, the second end ring 120, and all the crossbars. This adaptability design ensures that the coil will not shake inside the housing during operation, improving the stability of the structure and the comfort of the scanning object.

[0053] In one embodiment, such as Figure 7As shown, one or more observation windows are provided on the sides and / or top of the housing. These windows can be transparent openings or windows encapsulated in transparent materials such as acrylic. Their position and size can be designed according to the knee joint radio frequency coil 100 and actual needs, and are located outside the housing, on the crossbar and the two end rings. Understandably, the specific shape (e.g., rectangular, circular, elongated), number, and distribution of the observation windows within the housing can be adjusted according to actual observation needs. These changes all fall within the scope of protection of this invention. This design ensures that the operator has a sufficiently wide field of view to observe the positioning of the knee of the scanned object. In actual operation, the patient places their knee within the transceiver coil assembly 200. The operator can clearly see through the observation windows whether the internal flexible coil has correctly wrapped around the leg or whether the leg is centered in the imaging area, thus allowing for fine-tuning. Throughout the scanning process, the operator can also monitor the patient's movement through the observation windows, ensuring the reliability of the imaging process and image quality.

[0054] In one embodiment, such as Figure 7 and Figure 8 As shown, the outer shell of the knee joint radio frequency coil 100 adopts a split structure, which can be composed of an upper outer shell 410 and a lower outer shell 420. The upper outer shell 410 and the lower outer shell 420 are detachably connected. The first end ring 110, the second end ring 120, and the crossbar portion are respectively located in the upper outer shell 410 and the lower outer shell 420. In use, the upper outer shell 410 and the lower outer shell 420 are first disassembled and separated. After the knee joint of the scanned object is placed on the coil assembly, the two shells are then fixed together. The detachable connection method includes, but is not limited to, snap-fit ​​connection, screw connection, or magnetic connection. For example, threaded holes can be provided at corresponding positions on the edges of the upper and lower shells for fastening with screws; preferably, a snap-fit ​​422 can be installed on one of the upper outer shell 410 or the lower outer shell 420, and a corresponding slot can be installed on the other. The upper outer shell 410 and the lower outer shell 420 can be fixed and disassembled through the cooperation of the snap-fit ​​422 and the slot. The number of latches and their corresponding slots can be two, and they are respectively arranged on both sides of the housing along the width direction of the upper or lower housing. There is no specific limit to the number of latches and their corresponding slots; three or four can also be used depending on the actual situation. This design allows the housing to be opened and closed easily.

[0055] Furthermore, the upper outer shell 410 has a portion of a crossbar and portions of a first end ring 110 and a second end ring 120. A curved second crossbar 131 can be arranged in the upper outer shell 410. The corresponding part of the upper outer shell 410 is also curved to conform to the curvature of the knee of the scanning object. The lower outer shell 420 has a first crossbar 130 and portions of a first end ring 110 and a second end ring 120. After the upper and lower shells are combined, the crossbar, the first end ring 110 and the second end ring 120 in the two shells can form a complete knee joint radio frequency coil 100 and have a complete electrical circuit for transmitting magnetic resonance signals. The opening of the receiving cavity 430 of the shell can also be made into an elliptical shape to conform to the shape of the first end ring 110 and the second end ring 120, or made into a shape with one large and one small opening to conform to the circumference of the two end rings. More specifically, the upper housing 410 and the lower housing 420 are respectively provided with matching male and female plugs 421. When the upper and lower housings are fixed together by means of snaps, the male and female plugs are connected to each other, so that part of the cross section, the first end ring 110 and the second end ring 120 in the upper housing 410 can be electrically connected with part of the antenna in the lower housing 420 to form a complete electrical circuit and generate a uniform radio frequency field.

[0056] In one embodiment, the receiving coil 300 can be directly integrated into the housing. For example... Figure 7 and Figure 8 As shown, the receiving coil 300 is integrated inside the lower housing 420. Before an MRI scan, the physician can first fix the knee of the patient in the receiving coil 300, and then connect the upper housing 410 of the knee joint radiofrequency coil 100 to the lower housing 420. The receiving coil 300 can be detachably fixed to the lower housing 420 using adhesive, Velcro, or other methods. This design brings the receiving coil 300 closer to the scanning area, resulting in a clearer signal, which helps improve the signal-to-noise ratio of the reconstructed image, and also facilitates the storage and use of the receiving coil 300 and the knee joint radiofrequency coil 100.

[0057] Furthermore, the receiving coil 300 can be a flexible coil, and the flexible coil has an opening 330, through which the flexible coil can be wrapped around the target object. Figure 9This is a schematic diagram of the structure of a receiving coil 300 in this application. The receiving coil 300 can be composed of multiple coil units and a flexible substrate 320. The flexible substrate 320 can be made of materials such as polyimide film or other polymer film materials. The coil units are formed on the flexible substrate 320 by printing or etching processes. The multiple coil units can be decoupled using methods such as overlapping decoupling, capacitive decoupling, or inductive decoupling. Preferably, the multiple coil units are arranged in an overlapping array. The flexible coil as a whole can be in the form of a strip or sleeve, and has an opening 330 extending through its length. This opening 330 allows the receiving coil 300 to be opened so that the scanning object (such as a patient's knee) can be placed inside. Preferably, the edges of the opening 330 are provided with fasteners, such as Velcro, hooks, magnetic buckles, or elastic bands, for securely and adjustablely fixing the target object after wrapping around it. The receiving coil 300 adopts a flexible design, which can fit closely to the object being detected, improving signal reception quality.

[0058] In one embodiment, a pressure pad is also provided on the inner side of the upper outer shell 410. The shape of the pressure pad can conform to the knee joint. The pressure pad can be fixed by means of adhesive, screwing, etc. The number of pressure pads can be one or more, which is not specifically limited here. After the upper outer shell 410 and the lower outer shell 420 are fixed, the pressure pad can fit tightly against the knee joint of the scanned object, fixing the knee joint to prevent artifacts caused by the movement of the scanned object during scanning. By placing the pressure pad on the inner side of the upper outer shell 410, the pressure pad and the transceiver coil are integrated. After the doctor puts the coil on the scanned object, there is no need to insert a pad to fix the knee joint of the scanned object, simplifying the operation process.

[0059] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A knee joint radio frequency coil, characterized in that, include: First end ring (110); Second end ring (120); Multiple crossbars are disposed between the first end ring (110) and the second end ring (120); wherein, the crossbars include multiple first crossbars (130) and multiple second crossbars (131), each first crossbar (130) extends in a straight line, and each second crossbar (131) is provided with an arc-shaped protrusion to adapt to the joint of the protrusion of the detection object.

2. The knee joint radio frequency coil according to claim 1, characterized in that, Multiple first crossbar portions (130) are arranged at equal intervals along the circumference of the knee joint radio frequency coil (100), and multiple second crossbar portions (131) are arranged side by side along the circumference of the knee joint radio frequency coil (100).

3. The knee joint radio frequency coil according to claim 1, characterized in that, The second crossbar (131) includes at least two, and the two second crossbars (131) are set with a set bending angle to adapt to the knee of the scanned object.

4. The knee joint radio frequency coil according to claim 1, characterized in that, The circumference of the first end ring (110) is smaller than the circumference of the second end ring (120), and the capacitance on each end ring is proportional to its circumference.

5. A knee joint radio frequency coil, characterized in that, include: The lower part includes a lower housing (420) and a plurality of first crossbars (130) disposed in the lower housing, and an end ring lower part connected to the plurality of first crossbars (130). The plurality of first crossbars (130) are arranged sequentially along the circumference of the knee joint radio frequency coil (100), and each first crossbar (130) extends along the axial direction of the knee joint radio frequency coil (100). The upper part, detachably connected to the lower part, includes an upper housing (410) and at least one second crossbar (131) disposed in the upper housing (410), an upper end ring connected to a plurality of second crossbars (131), and at least a portion of the second crossbars (131) being bent; After the upper part is connected to the lower part, the plurality of first crossbars (130), the upper part of the end ring, the plurality of second crossbars (131) and the lower part of the end ring can form a transmitting coil with protrusions.

6. A transceiver coil assembly for magnetic resonance imaging at the knee joint, characterized in that, The transceiver coil includes: A knee joint radio frequency coil (100) includes a first end ring (110), a second end ring (120), and a plurality of crossbars; the crossbars are disposed between the first end ring (110) and the second end ring (120); wherein the crossbars include a plurality of first crossbars (130) and a plurality of second crossbars (131), each first crossbar (130) extending in a straight line, and each second crossbar (131) having an arc-shaped protrusion to adapt to the protruding joint of the detection object; The receiving coil (300) is located inside the knee joint radio frequency coil (100) and consists of multiple coil units.

7. The transceiver coil assembly according to claim 6, characterized in that, The circumference of the first end ring (110) is smaller than the circumference of the second end ring (120), and the capacitance on each end ring is proportional to its circumference.

8. The transceiver coil assembly according to claim 6, characterized in that, The transceiver coil assembly (200) also includes a housing that surrounds the knee joint radio frequency coil (100), the housing being made of a rigid material; wherein the housing has a receiving cavity (430) whose shape is adapted to the contour of the knee joint radio frequency coil (100).

9. The transceiver coil assembly according to claim 8, characterized in that, The outer shell is composed of an upper outer shell (410) and a lower outer shell (420), which are detachably connected. Parts of the first end ring (110), the second end ring (120), and the crossbar are located in the upper outer shell (410) and the lower outer shell (420), respectively.

10. The transceiver coil assembly according to claim 9, characterized in that, The receiving coil (300) is fixed to the lower housing (420) of the knee joint radio frequency coil (100); wherein the receiving coil (300) is a flexible coil with an opening (330) through which the flexible coil can be wrapped around the scanning object.

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