Coil assembly for dual knee joint magnetic resonance imaging

Abstract

The application relates to the technical field of magnetic resonance imaging, in particular to a coil assembly for double-knee magnetic resonance imaging. The coil assembly comprises: a first main body comprising a first coil unit and a first recess recessed from the outer surface of the first main body, the first recess being adapted to receive the double knees of a subject from the back side of the subject; a second main body detachably connected to the first main body, comprising a second coil unit and a second recess recessed from the outer surface of the second main body, the second recess being adapted to receive the double knees of the subject from the front side of the subject; wherein when the second main body is connected to the first main body, the first recess and the second recess define a continuous space accommodating the double knees.

Description

Technical Field

[0001] This application relates to the field of magnetic resonance imaging technology, and more particularly to a coil assembly for magnetic resonance imaging of the bilateral knee joints. Background Technology

[0002] Magnetic resonance imaging (MRI) is widely used in clinical practice. It involves no radiation and offers advantages over X-rays and CT scans, including higher soft tissue resolution, multi-planar imaging, and multi-sequence imaging, significantly improving disease detection and assessment rates. However, the long scan time and numerous contraindications of MRI limit its clinical application.

[0003] Coils are an essential component of MRI; they are necessary to complete an MRI scan. The function of a coil is to be placed at the site to be examined to receive signals from specific tissues for MRI scanning and signal acquisition. Specific areas require dedicated coils; for example, head, abdomen, and joint scans have corresponding head, abdomen, and joint-specific coils. Current knee joint scans are unilateral, allowing only one knee joint to be scanned at a time, taking 15-20 minutes. For bilateral symmetrical joint scans (such as bilateral knee or ankle joints), the coil must be placed on the other joint after scanning one side for repositioning; completing bilateral joint scans takes approximately 30-40 minutes. Current bilateral symmetrical joint scanning methods are time-consuming and limit clinical application. Clinically, there are many cases requiring bilateral symmetrical joint examinations, creating an urgent need for joint coils capable of simultaneously scanning both sides and shortening the scan time. Summary of the Invention

[0004] In view of this, this application provides a coil assembly for magnetic resonance imaging of both knee joints.

[0005] The coil assembly for bilateral knee joint magnetic resonance imaging proposed in this application includes:

[0006] A first body includes a first coil unit and a first recess recessed from the outer surface of the first body, the first recess being adapted to receive the subject's knees from the rear side of the subject;

[0007] A second body detachably connected to the first body includes a second coil unit and a second recess recessed from the outer surface of the second body, the second recess being adapted to receive the knees from the front of the subject;

[0008] When the second body is connected to the first body, the first recess and the second recess define a continuous space that accommodates the knees.

[0009] In some possible implementations, the first coil unit is located inside the first body and extends along the shape of the inner wall surface of the first recess; the second coil unit is located inside the second body and extends along the shape of the inner wall surface of the second recess.

[0010] In some possible implementations, the second body is configured to connect to the first body based on movement from the front side of the subject to the rear side of the subject, and to separate from the first body based on movement from the rear side of the subject to the front side of the subject.

[0011] In some possible implementations, a locking mechanism is included that can switch between a locked state and a released state;

[0012] In the locked state, the locking mechanism prevents the second body from separating from the first body;

[0013] In the released state, the locking mechanism allows the second body to separate from the first body.

[0014] In some possible implementations, the first body includes a first housing defining the first recess, and the first coil unit is mounted inside the first housing;

[0015] The second body includes a second housing defining the second recess, and the second coil unit is mounted inside the second housing.

[0016] In some possible implementations, the first recess has a first protrusion protruding toward the second recess at the midpoint of the left-right direction of the subject, and the second recess has a second protrusion protruding toward the first recess at the midpoint of the left-right direction of the subject.

[0017] When the second body is connected to the first body, the first protrusion and the second protrusion are opposite to each other and spaced apart from each other in the front-back direction of the subject. The first protrusion fills the gap between the knees from the rear side of the subject, and the second protrusion fills the gap between the knees from the front side of the subject.

[0018] In some possible implementations, the space allows the knees to be brought together.

[0019] In some possible implementations, the first body includes a first electrical connector disposed on the outer side of the first recess along the left-right direction of the subject.

[0020] The second body includes a second electrical connector disposed on the outer side of the second recess along the left-right direction of the subject, and connected to the second coil unit;

[0021] It also includes a signal transmission cable that extends from a first part of the first body and is connected to the first electrical connector and the first coil unit, wherein the first part is located in the middle of the first body in the left-right direction of the subject and at the end of the first body in the length direction of the subject.

[0022] When the second body is connected to the first body, the first electrical connector and the second electrical connector are connected to each other, and the magnetic resonance signal received by the second coil unit is transmitted to the signal transmission cable via the first electrical connector and the second electrical connector.

[0023] In some possible implementations, the space is constructed in a shape symmetrical about a virtual plane, which is a plane perpendicular to the left-right direction of the subject.

[0024] In some possible implementations, the first coil unit and the second coil unit are configured to: receive magnetic resonance signals from the knees, and / or transmit radio frequency signals to the knees.

[0025] According to the coil assembly provided in this application, magnetic resonance scanning of both knee joints can be completed simultaneously to shorten scanning time and improve examination efficiency. It also helps to compare images of the same tissues in the left and right knees to identify abnormal lesions, thereby improving the accuracy of lesion screening. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this application, and are not intended to limit this application.

[0027] Figure 1 This is a three-dimensional schematic diagram of the coil assembly provided in the embodiments of this application when viewed from the foot side of the examinee.

[0028] Figure 2 yes Figure 1 A schematic diagram of the coil assembly when the first and second bodies are separated.

[0029] Figure 3 Observing from another perspective Figure 2 A schematic diagram.

[0030] Figure 4 This is a schematic diagram of the coil assembly provided in the embodiments of this application after the first housing and the second housing have been opened.

[0031] Figure 5 Observing from another perspective Figure 4 A schematic diagram.

[0032] Figure 6 This is a schematic diagram of the coil unit arrangement in the coil assembly provided in the embodiments of this application.

[0033] Figure 7 This is a circuit structure block diagram of the coil assembly provided in the embodiments of this application.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1000-Magnetic Resonance Imaging Equipment;

[0036] 100-Coil Assembly;

[0037] 1-First main body, 1a-First part;

[0038] 2-Second subject;

[0039] 3-First shell, 3a-First recess, 3b-First protrusion;

[0040] 4-Second shell, 4a-Second recess, 4b-Second protrusion;

[0041] 5-space;

[0042] 6-First coil unit;

[0043] 7-Second coil unit;

[0044] 8-Left knee coil unit;

[0045] 9-Right knee coil unit;

[0046] 10-Locking mechanism;

[0047] 11-Locking component;

[0048] 12-Locked component

[0049] 13-First preamplifier;

[0050] 14 - Second preamplifier;

[0051] 15-Switch components;

[0052] 16-3dB four-port coupler;

[0053] 17-Power supply node;

[0054] 18-Spectrometer receiving channel;

[0055] 19-Magnetic Resonance Spectrometer;

[0056] 20 - First electrical connector;

[0057] 21 - Second electrical connector. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of the embodiments of this application 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 application. Based on the described embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. It is understood that, without conflict, some technical means of the various embodiments described herein can be substituted for or combined with each other.

[0059] In the description of this application, the terms "first," "second," etc., are used only to distinguish the described objects and have no sequential or technical meaning. Therefore, objects specified with "first," "second," etc., may explicitly or implicitly include one or more of those objects, and, for example, the term "first element" itself does not imply the existence of a "second element," nor does the term "second element" itself imply the existence of a "first element." Furthermore, words such as "a" or "one" do not indicate a quantity limitation, but rather indicate the presence of at least one, while "multiple" indicates not less than two.

[0060] Figures 1 to 7 A coil assembly 100 according to an embodiment of this application is shown. The coil assembly 100 can be used for magnetic resonance imaging of both knee joints or for magnetic resonance imaging of a single knee joint (left knee or right knee). It mainly includes a first body 1 and a second body 2 detachably connected to the first body 1.

[0061] The first body 1 includes a first housing 3, which is formed substantially entirely of plastic, and a plurality of first coil units 6 mounted within the first housing 3. The first housing 3 defines the entire outer surface of the first body 1 and defines a first recess 3a recessed from the outer surface of the first body 1 (which is also the outer surface of the first housing 3). The first coil units 6 are housed and protected by the first housing 3, and the first coil units 6 extend along the shape of the inner wall of the first recess 3a so as to be as close as possible to the knees of the subject during use.

[0062] The second body 2 includes a second housing 4 formed substantially entirely of plastic and a plurality of second coil units 7 mounted within the second housing 4. The second housing 4 defines the entire outer surface of the second body 2 and also defines a second recess 4a recessed from the outer surface of the second body 2 (which is also the outer surface of the second housing 4). The second coil units 7 are housed and protected by the second housing 4, and the second coil units 7 extend along the shape of the inner wall of the second recess 4a so as to be as close as possible to the knees of the subject during use.

[0063] The first recess 3a is shaped to receive the subject's knees from the rear, and the second recess 4a is shaped to receive the subject's knees from the front. When the second body 2 is connected to the first body 1, the first recess 3a and the second recess 4a define a continuous (i.e., uninterrupted) space 5 that accommodates the subject's knees.

[0064] Based on this design, in use, the subject's knees can be first placed into the first recess 3a of the first main body 1 from the opening side of the first recess 3a, that is, the first recess 3a receives the subject's knees from the rear side. Then, by moving the second main body 2 from the front side of the subject towards the knees, the second recess 4a receives the subject's knees from the front side. Since the space 5 defined by the first recess 3a and the second recess 4a is a continuous space 5, there is no partition between the subject's knees, allowing the subject's knees to be as close as possible in the left-right direction. This helps to reduce the size of the space 5 and thereby improves the proximity of the first coil unit 6 and the second coil unit 7 to the knees, improving the quality of magnetic resonance imaging.

[0065] In some embodiments, space 5 allows the knees to be close together, that is, allows the subject's knees to touch each other within space 5.

[0066] In this embodiment, the coil assembly 100, particularly the coil units 6 and 7 within it, is used to receive magnetic resonance signals from the subject's knee. In other embodiments, the coil units 6 and 7 in the coil assembly 100 can be used to transmit radio frequency signals to the subject's knee, serving as transmitting coils.

[0067] In this embodiment, the component further includes a locking mechanism 10 capable of switching between a locked state and a released state. In the locked state, the locking mechanism 10 prevents the second body 2 from separating from the first body 1. In the released state, the locking mechanism 10 allows the second body 2 to separate from the first body 1.

[0068] Specifically, the locking mechanism 10 includes a locking member 11 and a locked member 12. The locked member 12 is disposed on the first body 1 and includes a latch extending toward the front of the subject. The locking member 11 is disposed on the second body 2 and includes an unlocking button and an elastic component that applies a biasing force to the unlocking button.

[0069] In use, when the first body 1 receives the subject's knees from the rear, by moving the second body 2 from the front to the rear of the subject, the latch of the locking member 12 is inserted into the second body 2 and engages with the locking member 11. At this time, the second body 2 is connected to the first body 1, and the locking mechanism 10 remains in the locked state under the action of the elastic member. By pressing the unlock button of the locking member 11 to overcome the biasing force of the elastic member, the locking mechanism 10 switches to the released state. At this time, by moving the second body 2 from the rear to the front of the subject, the second body 2 is separated from the first body 1.

[0070] The first recess 3a has a first protrusion 3b protruding towards the second recess 4a at its midpoint along the left-right direction of the subject, and the second recess 4a has a second protrusion 4b protruding towards the first recess 3a at its midpoint along the left-right direction of the subject. When the second body 2 is connected to the first body 1, the first protrusion 3b and the second protrusion 4b are opposite to each other and spaced apart in the front-back direction of the subject. The first protrusion 3b fills the gap between the knees from the rear side of the subject, and the second protrusion 4b fills the gap between the knees from the front side of the subject. This design increases the support of the inner wall of the space 5 for the knees, thereby improving the user experience. It also helps to reduce the size of the space 5, thereby bringing the first coil unit 6 and the second coil unit 7 closer to the knees and improving the quality of magnetic resonance imaging.

[0071] Furthermore, there are two such locking mechanisms 10, which are respectively located on the two outer sides of the space 5 along the left and right directions of the examinee.

[0072] The first body 1 includes two first electrical connectors 20, which are respectively disposed on the two outer sides of the first recess 3a along the left-right direction of the subject. The second body 2 includes two second electrical connectors 21, which are respectively disposed on the two outer sides of the second recess 4a along the left-right direction of the subject, and the second electrical connectors 21 are connected to the second coil unit 7. A signal transmission cable (not shown) extends from a first part 1a of the first body 1 and connects to the first electrical connectors 20 and the first coil unit 6. The first part 1a is located in the middle of the first body 1 in the left-right direction of the subject and at the end of the first body 1 in the length direction of the subject. When the second body 2 is connected to the first body 1, the first electrical connectors 20 and 21 are connected to each other. The magnetic resonance signal received by the second coil unit 7 is transmitted to the signal transmission cable via the first electrical connectors 20 and 21, so as to transmit the magnetic resonance signal to the receiver of the magnetic resonance system.

[0073] Space 5 is constructed in a shape symmetrical about a virtual plane that is perpendicular to the subject's left and right directions.

[0074] Please see Figure 4 and Figure 6 In this embodiment, the first main body 1 contains eight first coil units 6. The four first coil units 6 on the left (from the examinee's perspective) correspond to the examinee's left knee and are mainly used to receive magnetic resonance signals from the examinee's left knee; these can be referred to as left knee coil units 8. The other four first coil units 6 on the right correspond to the examinee's right knee and are mainly used to receive magnetic resonance signals from the examinee's right knee; these can be referred to as right knee coil units 9. Similar to the first coil units 6, the second main body 2 also contains eight second coil units 7. The four second coil units 7 on the left correspond to the examinee's left knee and are mainly used to receive magnetic resonance signals from the examinee's left knee; these can also be referred to as left knee coil units 8. The other four second coil units 7 on the right correspond to the examinee's right knee and are mainly used to receive magnetic resonance signals from the examinee's right knee; these can also be referred to as right knee coil units 9. That is, the four first coil units 6 and four second coil units 7 on the left side define eight left knee coil units 8, and the four first coil units 6 and four second coil units 7 on the right side define eight right knee coil units 9.

[0075] Each first coil unit 6 and each second coil unit 7 is connected to a preamplifier, that is, the 16 coil units are connected to 16 preamplifiers in a one-to-one correspondence. The output impedance of each preamplifier is 50 ohms. For ease of explanation, the eight preamplifiers connected to the eight right knee coil units 9 are referred to as first preamplifiers 13, and the eight preamplifiers connected to the eight right knee coil units 9 are referred to as second preamplifiers 14. In this embodiment, the eight left knee coil units 8 and the eight right knee coil units 9 are also symmetrical about the aforementioned virtual plane.

[0076] Additionally, a switching component 15 is provided. This switching component 15 is used to connect to the power supply node 17 that provides operating power to the preamplifier, and controls the operating state of the preamplifier by operating the switching component 15 in different states. The power supply node 17 can be a circuit node that provides DC power. The switching device can be a rocker switch.

[0077] Specifically, the switching component 15 has at least three operating states: a first state (left knee open), a second state (left knee open), and a third state (right knee open). In the first state, the switching component 15 couples the power supply node 17 to the eight left knee coil units 8 on the left side and decouples the power supply node 17 from the eight right knee coil units 9 on the right side, thus using these eight left knee coil units 8 to perform magnetic resonance imaging (MRI) on the subject's left knee joint. In the second state (right knee open), the switching component 15 couples the power supply node 17 to the eight left knee coil units 8 on the left side and decouples the power supply node 17 from the eight right knee coil units 9 on the right side, thus using these eight right knee coil units 9 to perform MRI on the subject's right knee joint. In the third state (both knees open), the switching component 15 couples the power supply node 17 to all 16 coil units, namely eight first coil units 6 and eight second coil units 7, thus performing MRI on both knee joints of the subject.

[0078] As described in the background section of this application, some magnetic resonance imaging (MRI) systems have relatively low intelligence. Each imaging session requires selecting all predefined radio frequency (RF) channels for acquisition. If some channels are found to lack RF signals, the system may report an error and stop scanning, or image artifacts may occur during image reconstruction. To avoid the aforementioned problems when the coil assembly 100 of this embodiment is applied to such an MRI system, please refer to... Figure 7The coil assembly 100 is also equipped with eight 3dB four-port couplers 16 (3dB Hybrid). Each 3dB four-port coupler 16 has two input ports and two output ports. The two input ports are connected to a first preamplifier 13 and a second preamplifier 14, respectively, and the two output ports are used to connect to two spectrometer receiving channels 18, respectively. That is, the 16 output ports of the eight 3dB four-port couplers 16 are used to connect to 16 spectrometer receiving channels 18.

[0079] As is well known, 3dB four-port couplers have orthogonal output characteristics. Therefore, when both input ports are supplied with magnetic resonance signals, the signal is evenly distributed to the two output ports. When only one input port is supplied with a magnetic resonance signal (RF signal), as long as the other input port is in a 50-ohm matching state (this state only requires the output impedance of the corresponding preamplifier to be 50 ohms), the single-input magnetic resonance signal will be split into two orthogonal output signals, completely isolated from the other input port, so that the four ports are still in a good state of matching, power splitting, and isolation.

[0080] Therefore, when the switch component 15 is in the left knee open state, the 8 (N) channels (coil units) of the left knee will be divided into 16 (2) RF receiving channels; when the switch component 15 is in the right knee open state, the 8 channels of the right knee will be divided into 16 RF receiving channels; when the switch component 15 is in the double knee open state, the 8 channels of the left knee will be divided into 16 RF receiving channels, and the 8 channels of the right knee will also be divided into 16 RF receiving channels, but due to channel multiplexing, the number of output channels is still 16.

[0081] As can be seen, in this embodiment, regardless of whether the coil assembly 100 is in single-knee working mode or double-knee working mode, all 16 output channels have signals, which will not cause system misjudgment or image problems. Moreover, regardless of the state, the system is in a state of good port matching and isolation, ensuring good coil reception performance.

[0082] Obviously, the number of left knee coil units 8 and right knee coil units 9 can be other than 2. However, considering the equal distribution of each of the left knee coil units 8 and right knee coil units 9 in the first body 1 and the second body 2, and the uniformity of the signal, the number of both the left knee coil units 8 and right knee coil units 9 is preferably an integer multiple of 2. That is, the number of left knee coil units 8 and right knee coil units 9 can also be N, which is not equal to 8 but is a positive even number.

[0083] This application also provides a magnetic resonance imaging (MRI) device 1000, such as... Figure 7As shown, it includes the aforementioned coil assembly 100, and also includes a DC power supply node 17 connected to the switching member 15 and a magnetic resonance spectrometer 19 connected to the output ports of each 3dB four-port coupler 16 via the spectrometer receiving channel 18.

Claims

1. A coil assembly for dual knee joint magnetic resonance imaging, characterized by, include: A first body includes a first coil unit and a first recess recessed from the outer surface of the first body, the first recess being adapted to receive the subject's knees from the rear side of the subject; A second body detachably connected to the first body includes a second coil unit and a second recess recessed from the outer surface of the second body, the second recess being adapted to receive the knees from the front of the subject; When the second body is connected to the first body, the first recess and the second recess define a continuous space that accommodates the knees.

2. The coil assembly of claim 1, wherein, The first coil unit is located inside the first body and extends along the shape of the inner wall of the first recess; the second coil unit is located inside the second body and extends along the shape of the inner wall of the second recess.

3. The coil assembly of claim 1, wherein, The second body is configured to connect to the first body based on movement from the front side of the subject to the rear side of the subject, and to separate from the first body based on movement from the rear side of the subject to the front side of the subject.

4. The coil assembly of claim 1, wherein, Includes a locking mechanism that can switch between locked and released states; In the locked state, the locking mechanism prevents the second body from separating from the first body; In the released state, the locking mechanism allows the second body to separate from the first body.

5. The coil assembly according to claim 1, characterized in that, The first body includes a first housing defining the first recess, and the first coil unit is mounted inside the first housing; The second body includes a second housing defining the second recess, and the second coil unit is mounted inside the second housing.

6. The coil assembly of claim 1, wherein, The first depression has a first protrusion protruding toward the second depression at the middle position along the left-right direction of the examinee, and the second depression has a second protrusion protruding toward the first depression at the middle position along the left-right direction of the examinee. When the second body is connected to the first body, the first protrusion and the second protrusion are opposite to each other and spaced apart from each other in the front-back direction of the subject. The first protrusion fills the gap between the knees from the rear side of the subject, and the second protrusion fills the gap between the knees from the front side of the subject.

7. The coil assembly of claim 1, wherein, The space allows the knees to be brought together.

8. The coil assembly according to claim 1, characterized in that, The first body includes a first electrical connector disposed on the outer side of the first recess along the left-right direction of the subject; The second body includes a second electrical connector disposed on the outer side of the second recess along the left-right direction of the subject, and connected to the second coil unit; It also includes a signal transmission cable that extends from a first part of the first body and is connected to the first electrical connector and the first coil unit, wherein the first part is located in the middle of the first body in the left-right direction of the subject and at the end of the first body in the length direction of the subject. When the second body is connected to the first body, the first electrical connector and the second electrical connector are connected to each other, and the magnetic resonance signal received by the second coil unit is transmitted to the signal transmission cable via the first electrical connector and the second electrical connector.

9. The coil assembly of claim 1, wherein, The space is constructed in a shape symmetrical about a virtual plane, which is a plane perpendicular to the left and right directions of the subject.

10. The coil assembly of claim 1, wherein, The first coil unit and the second coil unit are configured to: receive magnetic resonance signals from the knees, and / or transmit radio frequency signals to the knees.

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