Coil assembly and equipment capable of being used for magnetic resonance imaging of double knee joints and single knee joint

Abstract

The invention relates to the technical field of magnetic resonance imaging, in particular to a coil assembly and equipment for magnetic resonance imaging of double knee joints and single knee joint. The coil assembly comprises: N left knee coil units for receiving magnetic resonance signals from a left knee; n right knee coil units for receiving magnetic resonance signals from right knees; the N first preamplifiers are connected with the N left knee coil units in a one-to-one correspondence manner; the N second pre-amplifiers are connected with the N right knee coil units in a one-to-one correspondence manner; the switching device is used for being connected to a power supply node, coupling the power supply node to the N first preamplifiers and decoupling the power supply node from the N second preamplifiers in a first working state; in the second working state, the power supply node is coupled to the N second pre-amplifiers, and the power supply node is decoupled from the N first pre-amplifiers; in a third operating state, the power supply node is coupled to the N first preamplifiers and the N second preamplifiers.

Description

Technical Field

[0001] The present application relates to the field of nuclear magnetic resonance technology, and in particular to a coil assembly and device that can be used for magnetic resonance imaging of both knee joints and a single knee joint. Background Art

[0002] Magnetic resonance imaging (MRI) is widely used in clinical practice. It is radiation-free and offers advantages over plain X-rays and CT, such as high soft tissue resolution, multi-directional imaging, and multiple imaging sequences. This significantly improves disease detection rates. However, MRI's long scanning times and numerous contraindications limit its clinical application.

[0003] The coil is an important and indispensable component of MRI and is required to complete a magnetic resonance imaging examination. The function of the coil is to be placed at the site to be examined in order to receive specific tissues for MRI scanning and signal collection. Certain sites have specific dedicated coils, such as for scanning the head, abdomen, and joints, there are corresponding dedicated coils for the head, abdomen, and joints. Existing knee joints are all used unilaterally and can only complete a single knee joint scan at a time, which takes 15-20 minutes. If a bilaterally symmetrical joint scan is performed (such as bilateral knee joints or ankle joints), after scanning one side of the joint, the coil is placed on the other side of the joint for repositioning and scanning; it takes about 30-40 minutes to complete the scan of both joints. The current bilaterally symmetrical joint scanning method is time-consuming and has limitations in clinical application. Clinically, there are many cases of bilaterally symmetrical joint examinations, and there is an urgent need for a joint coil that can simultaneously complete bilaterally symmetrical joint scans and shorten the scanning time.

[0004] Furthermore, to ensure proper matching between the coil assembly and the MRI system (particularly the MRI spectrometer), each coil unit in the coil assembly has its own identification ID. This coil ID defines the MRI system's definition of the coil unit, such as the number of output channels. Some MRI systems are relatively intelligent, selecting the appropriate number of channels to acquire MRI signals based on the number of channels in the coil assembly. However, some MRI systems are less intelligent and require all defined RF channels to be selected for acquisition during each imaging session. If the system detects the absence of RF signals (MRI signals) on some channels, it may report an error and halt the scan, or cause image artifacts during reconstruction. Summary of the Invention

[0005] In order to solve at least one of the above technical problems, the present application provides a coil assembly and a device that can be used for magnetic resonance imaging of both knee joints and a single knee joint.

[0006] In a first aspect, a coil assembly for magnetic resonance imaging of both knee joints and a single knee joint is provided, comprising:

[0007] N left knee coil units are configured to receive magnetic resonance signals from the left knee of the subject, where N is a positive integer;

[0008] N right knee coil units, configured to receive magnetic resonance signals from the right knee of the subject;

[0009] N first preamplifiers, connected to the N left knee coil units in a one-to-one correspondence;

[0010] N second preamplifiers, connected to the N right knee coil units in a one-to-one correspondence;

[0011] A switching device is configured to be connected to a power supply node and has a first operating state, a second operating state, and a third operating state; in the first operating state, the power supply node is coupled to the N first preamplifiers and the power supply node is decoupled from the N second preamplifiers; in the second operating state, the power supply node is coupled to the N second preamplifiers and the power supply node is decoupled from the N first preamplifiers; and in the third operating state, the power supply node is coupled to the N first preamplifiers and the N second preamplifiers.

[0012] In some possible implementations, the following further comprises:

[0013] N 3dB four-port couplers, each of the 3dB four-port couplers has two input ports and two output ports, the two input ports are respectively connected to one of the first preamplifiers and one of the second preamplifiers, and the two output ports are respectively connected to two spectrometer receiving channels.

[0014] In some possible implementations, the output impedance of the first preamplifier and the output impedance of the second preamplifier are both 50 ohms.

[0015] In some possible implementations, the switch device is a rocker switch.

[0016] In some possible implementations, the N left knee coil units and the N right knee coil units are symmetrical about a virtual plane, where the virtual plane is a plane perpendicular to the left-right direction of the subject.

[0017] In some possible implementations, the coil assembly includes:

[0018] a first body comprising a portion of the N left knee coil units, a portion of the N right knee coil units, and a first recess recessed from an outer surface of the first body, the first recess being adapted to receive both knees of the subject from the back side of the subject;

[0019] A second body detachably connected to the first body includes the remaining portion of the N left knee coil units, the remaining portion of the N right knee coil units, and a second recess recessed from an outer surface of the second body, wherein the second recess is suitable for receiving the two knees from the front side of the subject.

[0020] In some possible embodiments, N is a positive even number, the first body includes N / 2 of the N left knee coil units and N / 2 of the N right knee coil units, and the second body includes the remaining N / 2 of the N left knee coil units and the remaining N / 2 of the N right knee coil units.

[0021] In some possible implementations, when the second body is connected to the first body, the first recess and the second recess define a continuous space that accommodates the left knee and the right knee.

[0022] In some possible implementations, 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.

[0023] In a second aspect, a magnetic resonance device is provided, comprising:

[0024] The coil assembly according to the first aspect, and

[0025] The power supply node. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings described below only relate to some embodiments of the present application, and are not limitations to the present application.

[0027] Figure 1 This is a three-dimensional schematic diagram of the coil assembly provided in an embodiment of the present application when observed from the sole side of the subject's foot.

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

[0029] Figure 3 From another perspective Figure 2 Schematic diagram of .

[0030] Figure 4 This is a schematic diagram of the coil assembly provided by an embodiment of the present application after the first shell and the second shell are opened.

[0031] Figure 5From another perspective Figure 4 Schematic diagram of .

[0032] Figure 6 Schematic diagram of the arrangement of coil units in the coil assembly provided in an embodiment of the present application.

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

[0034] Description of reference numerals:

[0035] 1000-Magnetic resonance equipment;

[0036] 100-coil assembly;

[0037] 1-first body, 1a-first part;

[0038] 2- Second subject;

[0039] 3-first housing, 3a-first recess, 3b-first protrusion;

[0040] 4-second housing, 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 member;

[0048] 12-locked component

[0049] 13- first preamplifier;

[0050] 14- Second preamplifier;

[0051] 15- switch member;

[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 DESCRIPTION

[0058] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below in conjunction with the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application. It is understood that, in the absence of conflict, some technical means of the various embodiments described herein can be replaced or combined with each other.

[0059] In the description of this application, the terms "first," "second," etc., if used, are used solely to distinguish the objects being described and do not convey any order or technical meaning. Thus, an object defined as "first," "second," etc. may explicitly or implicitly include one or more of such objects. Furthermore, for example, the term "first element" alone does not imply the presence of a "second element," nor does the term "second element" alone imply the presence of a "first element." Furthermore, the terms "a" or "an," and the like, do not denote a limitation on quantity, but rather indicate the presence of at least one, and "plurality" means at least two.

[0060] Figures 1 to 7 A coil assembly 100 provided according to an embodiment of the present 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). The coil assembly 100 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 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 within the first housing 3 and extend along the inner wall of the first recess 3a, ensuring that they are positioned as close to the patient's knees as possible 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 within the second housing 4 and extend along the inner wall of the second recess 4a, ensuring that they are positioned as close to the patient's knees as possible during use.

[0063] Among them, the shape of the first recess 3a is designed to be suitable for receiving the subject's knees from the back side of the subject, and the shape of the second recess 4a is designed to be suitable for receiving the subject's knees from the front side. 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., unbroken) space 5, which accommodates the subject's knees.

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

[0065] According to the coil assembly 100 provided in the present application, magnetic resonance scanning of both knee joints can be completed simultaneously to shorten the scanning time and improve the inspection efficiency, and it is helpful to compare images of the same tissues of the left and right knees to find the location of abnormal lesions, which helps to improve the screening accuracy of lesions.

[0066] In some embodiments, the space 5 allows the two knees to be brought together, ie, allows the two knees of the subject to contact each other within the space 5 .

[0067] In this embodiment, the coil assembly 100, particularly the coil units 6 and 7 in the coil assembly 100, 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 a transmitting coil.

[0068] In this embodiment, the assembly further includes a locking mechanism 10 that can be switched between a locked state and a released state. In the locked state, the locking mechanism 10 prevents the second body 2 from being separated from the first body 1. In the released state, the locking mechanism 10 allows the second body 2 to be separated from the first body 1.

[0069] Specifically, the locking mechanism 10 includes a locking member 11 and a locked member 12. The locked member 12 is provided on the first body 1 and includes a latch extending toward the front side of the subject, while the locking member 11 is provided on the second body 2 and includes an unlocking button and an elastic component that applies a biasing force to the unlocking button.

[0070] In use, with the first body 1 receiving the subject's knees from the back, the second body 2 is moved from the front to the back of the subject, and the latch pin 12, which is the locked member 12, is inserted into the second body 2 and engages with the locking member 11. At this point, the second body 2 is connected to the first body 1, and the locking mechanism 10 is maintained in the locked state under the action of the elastic member. By pressing the unlocking button of the locking member 11 to overcome the biasing force of the elastic member, the locking mechanism 10 is switched to the released state. At this time, the second body 2 is separated from the first body 1 by moving the second body 2 from the back to the front of the subject.

[0071] The first recess 3a has a first protrusion 3b protruding toward the second recess 4a at its center along the left-right direction of the subject, and the second recess 4a has a second protrusion 4b protruding toward the first recess 3a at its center 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 and spaced apart from each other in the front-to-back direction of the subject. The first protrusion 3b fills the gap between the knees from the back of the subject, and the second protrusion 4b fills the gap between the knees from the front of the subject. This design, on the one hand, increases the support provided by the inner wall of the space 5 to the knees, thereby improving the user experience of the subject. On the other hand, it helps to reduce the size of the space 5, thereby shortening the distance between the first coil unit 6 and the second coil unit 7 and the knees, improving the quality of magnetic resonance imaging.

[0072] Furthermore, two such locking mechanisms 10 are provided, and the two locking mechanisms 10 are respectively arranged at both outer sides of the space 5 along the left-right direction of the subject.

[0073] The first body 1 includes two first electrical connectors 20, one located on either side of the first recess 3a, along the left-right direction of the subject. The second body 2 includes two second electrical connectors 21, one located on either side of the second recess 4a, along the left-right direction of the subject. These second electrical connectors 21 are connected to the second coil unit 7. A signal transmission cable (not shown) extends from a first portion 1a of the first body 1, located in the middle of the first body 1 in the left-right direction of the subject and at one end of the first body 1 in the lengthwise direction of the subject, and connects to the first electrical connectors 20 and the first coil unit 6. When the second body 2 is connected to the first body 1, the first electrical connector 20 and the second electrical connector 21 are connected. Magnetic resonance signals received by the second coil unit 7 are transmitted via the first and second electrical connectors 20, 21 to the signal transmission cable, which then transmits the magnetic resonance signals to a receiver of the magnetic resonance system.

[0074] The space 5 is configured in a symmetrical shape with respect to a virtual plane that is a plane perpendicular to the left-right direction of the subject.

[0075] See Figure 4 and Figure 6 In this embodiment, the first body 1 includes eight first coil units 6. The four first coil units 6 on the left side (from the subject's perspective) are positioned to correspond to the subject's left knee and are primarily used to receive magnetic resonance signals from the subject's left knee. They can be referred to as left knee coil units 8. The other four first coil units 6 on the right side are positioned to correspond to the subject's right knee and are primarily used to receive magnetic resonance signals from the subject's right knee. They can be referred to as right knee coil units 9. Similar to the first coil units 6, the second body 2 also includes eight second coil units 7. The four second coil units 7 on the left side are positioned to correspond to the subject's left knee and are primarily used to receive magnetic resonance signals from the subject's left knee. They can also be referred to as left knee coil units 8. The other four second coil units 7 on the right side are positioned to correspond to the subject's right knee and are primarily used to receive magnetic resonance signals from the subject's right knee. They can also be referred to as right knee coil units 9. That is, the four first coil units 6 and the four second coil units 7 on the left side define eight left knee coil units 8 , and the four first coil units 6 and the four second coil units 7 on the right side define eight right knee coil units 9 .

[0076] 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 the convenience of explaining the present technology, 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.

[0077] A switch component 15 is also provided. This switch component 15 is connected to a power supply node 17 that provides operating power to the preamplifier. By operating the switch component 15 in different states, the operating state of the preamplifier is controlled. Power supply node 17 may be a circuit node that provides DC power. The switch device may be a rocker switch.

[0078] Specifically, the switch member 15 has at least three operating states: first, second, and third. The first operating state is the left knee open state, in which the switch member 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, thereby performing magnetic resonance imaging of the subject's left knee joint using these eight left knee coil units 8 alone. The second operating state is the right knee open state, in which the switch member 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, thereby performing magnetic resonance imaging of the subject's right knee joint using these eight right knee coil units 9 alone. The third operating state is the double knee open state, in which the switch member 15 couples the power supply node 17 to all 16 coil units, namely, the eight first coil units 6 and the eight second coil units 7, thereby performing magnetic resonance imaging of both knee joints of the subject.

[0079] As described in the background of this application, some magnetic resonance systems have relatively low intelligence. Each imaging session requires the selection of all defined radio frequency channels for acquisition. If no radio frequency signal is detected in some channels, the system may report an error and stop scanning, or image artifacts may appear during imaging reconstruction. To avoid the aforementioned problems when the coil assembly 100 of this embodiment is applied to such a magnetic resonance system, please review Figure 7The coil assembly 100 is further configured 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 respectively connected to a first preamplifier 13 and a second preamplifier 14, and the two output ports are respectively connected to two spectrometer receiving channels 18. In other words, the total of 16 output ports of the eight 3dB four-port couplers 16 are respectively connected to 16 spectrometer receiving channels 18.

[0080] As is well known, a 3dB four-port coupler features orthogonal outputs. Therefore, when both input ports are supplied with a magnetic resonance signal, the signal is split equally between 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 corresponding preamplifier's output impedance to be 50 ohms), the single-channel input magnetic resonance signal is split into two orthogonal output signals, completely isolated from the other input port, ensuring that all four ports maintain a well-matched, power-splitting, and isolated state.

[0081] 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 powered 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 powered 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 powered divided into 16 RF receiving channels, and the 8 channels of the right knee will also be powered divided into 16 RF receiving channels, but due to channel multiplexing, the number of output channels is still 16.

[0082] It can be seen that in this embodiment, no matter whether the coil assembly 100 is in the single-knee working mode or the double-knee working mode, all 16 output channels have signals, which will not cause system misjudgment or image problems. Moreover, no matter which state it is in, the system is in a port matching and well-isolated state, ensuring the good receiving performance of the coil.

[0083] Obviously, the number of left knee coil units 8 and right knee coil units 9 can also be other numbers. However, to ensure equal distribution of each of the left knee coil units 8 and right knee coil units 9 in the first and second bodies 1 and 2, as well as to ensure signal uniformity, the number of 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, a positive even number other than 8.

[0084] The present application also provides a magnetic resonance device 1000. Figure 7As shown, it includes the coil assembly 100 described above, and further includes a DC power supply node 17 connected to the switch member 15 and a magnetic resonance spectrometer 19 connected to the output ports of each 3dB four-port coupler 16 via a spectrometer receiving channel 18.

Claims

1. A coil assembly for magnetic resonance imaging of both knee joints and one knee joint, characterized in that: include: N left knee coil units are configured to receive magnetic resonance signals from the left knee of the subject, where N is a positive integer; N right knee coil units, configured to receive magnetic resonance signals from the right knee of the subject; N first preamplifiers, connected to the N left knee coil units in a one-to-one correspondence; N second preamplifiers, connected to the N right knee coil units in a one-to-one correspondence; a switching device, configured to be connected to a power supply node and having a first operating state, a second operating state, and a third operating state; in the first operating state, coupling the power supply node to the N first preamplifiers and decoupling the power supply node from the N second preamplifiers; In the second working state, coupling the power supply node to the N second preamplifiers and decoupling the power supply node from the N first preamplifiers; In the third operating state, the power supply node is coupled to the N first preamplifiers and the N second preamplifiers.

2. The coil assembly according to claim 1, wherein Also includes: N 3dB four-port couplers, each of the 3dB four-port couplers has two input ports and two output ports, the two input ports are respectively connected to one of the first preamplifiers and one of the second preamplifiers, and the two output ports are respectively connected to two spectrometer receiving channels.

3. The coil assembly according to claim 1 or 2, characterized in that: The output impedance of the first preamplifier and the output impedance of the second preamplifier are both 50 ohms.

4. The coil assembly according to claim 1 or 2, characterized in that: The switch device is a rocker switch.

5. The coil assembly according to claim 1 or 2, characterized in that: The N left knee coil units and the N right knee coil units are symmetrical about a virtual plane, which is a plane perpendicular to the left-right direction of the subject.

6. The coil assembly according to claim 1 or 2, characterized in that: The coil assembly comprises: a first body comprising a portion of the N left knee coil units, a portion of the N right knee coil units, and a first recess recessed from an outer surface of the first body, the first recess being adapted to receive both knees of the subject from the back side of the subject; A second body detachably connected to the first body includes the remaining portion of the N left knee coil units, the remaining portion of the N right knee coil units, and a second recess recessed from an outer surface of the second body, wherein the second recess is suitable for receiving the two knees from the front side of the subject.

7. The coil assembly according to claim 6, wherein: N is a positive even number, the first body includes N / 2 of the N left knee coil units and N / 2 of the N right knee coil units, and the second body includes the remaining N / 2 of the N left knee coil units and the remaining N / 2 of the N right knee coil units.

8. The coil assembly according to claim 6, wherein: When the second body is connected to the first body, the first recess and the second recess define a continuous space that accommodates the left knee and the right knee.

9. The coil assembly according to claim 6, wherein: 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.

10. A magnetic resonance device, characterized in that: include: The coil assembly according to any one of claims 1 to 9, and The power supply node.

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