Magnetic resonance coil assembly, multi-nuclide imaging method and scanning equipment

Abstract

The present application relates to a magnetic resonance coil assembly, a multi-nuclide imaging method, and a scanning device, which excites at least two nuclides in the test object by applying multi-frequency excitation pulses to the test object. A first coil is used to receive the magnetic resonance signal generated by the first nuclide, and a second coil is used to receive the magnetic resonance signal generated by the second nuclide. The first coil and the second coil are placed in different temperature environments. Since the first nuclide is present in a relatively high concentration in the subject, the imaging effect will not be affected by using a normal temperature coil to receive the magnetic resonance signal generated by the first nuclide and a low temperature coil to receive the magnetic resonance signal generated by the second nuclide. In the imaging method using a combination of a normal temperature coil and a low temperature coil, the low temperature coil only receives signals from a single nuclide and only needs to be tuned for the second nuclide. Moreover, when the frequency deviates far from the first nuclide, there is no need to consider the detuning circuit of the frequency of the first nuclide, so the technical difficulty is greatly reduced.

Description

Technical Field

[0001] The present application relates to the field of medical device technology, and in particular to a magnetic resonance coil assembly, a multi-nuclide imaging method, and a scanning device. Background Art

[0002] Magnetic Resonance Imaging (MRI) technology is a process in which radio frequency pulses are sent to the subject through a radio frequency transmitting coil, which excites the resonance of atomic nuclei (such as hydrogen nuclei) of a specific frequency in the subject to generate magnetic resonance signals. The radio frequency receiving coil then processes the received signals with a computer to form an image of the subject.

[0003] First, when MRI is used for small animal imaging, due to the small size of the subjects and the high resolution required, a higher SNR is generally required. This requires a higher field strength to obtain images with sufficiently high SNR and resolution.

[0004] Secondly, multi-nuclide imaging is sensitive to the magnetic resonance signals produced by two nuclei with specific frequencies. These nuclides can be H, Na, P, F, etc. Generally, due to the low abundance of nuclides other than H in the specimen, it is difficult to achieve a SNR level that can be used for analysis.

[0005] Cryogenic coil technology can reduce the noise of the coil itself, thereby reducing overall noise and, in turn, improving the overall SNR of the image. However, implementing dual-frequency technology with cryogenic coils is challenging. Firstly, the physical space required for the coils is limited, specifically the mechanical structure housing the antenna. Secondly, due to the high Q factor of cryogenic coils, frequency offsets are more sensitive to SNR than normal-temperature coils. This requires an additional tuning mechanism to ensure accurate coil frequency, and the need to tune both frequencies makes this technically challenging to implement. Summary of the Invention

[0006] Based on this, the present application provides a magnetic resonance coil assembly, a multi-nuclide imaging method and a scanning device, which uses a method of combining a normal temperature coil and a low temperature coil to achieve dual-nuclide imaging. Since the low temperature coil only receives signals from a single nuclide, the technical difficulty is greatly reduced.

[0007] A multi-nuclide imaging method, comprising:

[0008] Applying a multi-frequency excitation pulse to a detection object to excite at least two nuclides in the detection object, wherein the at least two nuclides include a first nuclide and a second nuclide;

[0009] Using a first coil to receive a magnetic resonance signal generated by the first nuclear species, and using a second coil to receive a magnetic resonance signal generated by the second nuclear species;

[0010] Wherein, the first coil and the second coil are placed in different temperature environments.

[0011] In one embodiment, the first nuclide is H, and the second nuclide is other nuclide except H; the first coil is placed in a room temperature environment, and the second coil is placed in a low temperature environment.

[0012] In one embodiment, the first nuclide is H, and the second nuclide includes Na, P, or F; the first coil is placed in an environment of 20°C to 30°C, and the second coil is placed in an environment of -248.15°C to -193.15°C.

[0013] In one embodiment, the multi-frequency excitation pulse is applied to the detection object using the first coil;

[0014] Alternatively, a first nuclear species excitation pulse is applied to the detection object using the first coil, and a second nuclear species excitation pulse is applied to the detection object using the second coil.

[0015] A magnetic resonance coil assembly, comprising:

[0016] a first coil, configured to receive a magnetic resonance signal generated by a first nuclear species in a first temperature environment;

[0017] a second coil for receiving a magnetic resonance signal generated by a second nuclear species in a second temperature environment;

[0018] The first temperature environment and the second temperature environment are different temperature environments.

[0019] In one embodiment, the first nuclide is H, and the second nuclide is other nuclide except H; the first temperature environment is a normal temperature environment, and the second temperature environment is a low temperature environment.

[0020] In one embodiment, the second nuclide includes Na, P or F; the first temperature environment is an environment of 20°C to 30°C, and the second temperature environment is an environment of -248.15°C to -193.15°C.

[0021] In one embodiment, the first coil is a dual-frequency transmitting and receiving coil, and the second coil is a single-frequency receiving coil;

[0022] Alternatively, the first coil is a single-frequency transmitting and receiving coil, and the second coil is a single-frequency transmitting and receiving coil.

[0023] A multi-nuclide scanning device comprises the magnetic resonance coil assembly according to any one of the above embodiments.

[0024] In one embodiment, a cooling device is further included, wherein the cooling device is used to keep the second coil in a second temperature environment.

[0025] A multi-nuclide imaging system includes the multi-nuclide scanning device described in the above embodiment.

[0026] A computer device includes a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the multi-nuclide imaging method described in any one of the above embodiments when executing the computer program.

[0027] The multi-nuclide imaging method applies multi-frequency excitation pulses to the subject to excite at least two nuclides in the subject, including a first and a second nuclide. A first coil receives the magnetic resonance signal generated by the first nuclide, while a second coil receives the magnetic resonance signal generated by the second nuclide. The first and second coils are placed in different temperature environments. Because the first nuclide is present in a high concentration within the subject, using a room-temperature coil to receive the magnetic resonance signal generated by the first nuclide and a low-temperature coil to receive the magnetic resonance signal generated by the second nuclide does not affect the imaging effect. Furthermore, dual-nuclide imaging is achieved by combining room-temperature and low-temperature coils. Since the low-temperature coil only receives signals from a single nuclide, tuning only needs to be performed for the second nuclide. Furthermore, when the frequency deviates significantly from the first nuclide, there is no need to consider the detuning circuit for the frequency of the first nuclide, thus significantly reducing the technical difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 A schematic flow chart of a multi-nuclide imaging method provided in one embodiment of the present application;

[0030] Figure 2 A schematic diagram of an application of a magnetic resonance coil assembly provided in one embodiment of the present application;

[0031] Figure 3 A schematic diagram of the dual-frequency birdcage coil structure provided in one embodiment of the present application.

[0032] Description of the main components

[0033] 10. First coil; 20. Cooling device; 30. Second coil; 21. Cooler;

[0034] 22. Cooling conductor; 23. Shell. DETAILED DESCRIPTION

[0035] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar modifications without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0036] It will be understood that the terms "first," "second," and the like, as used herein, may be used to describe various elements herein, but these elements are not limited by these terms. These terms are used solely to distinguish a first element from another element. For example, a first acquisition module may be referred to as a second acquisition module, and similarly, a second acquisition module may be referred to as a first acquisition module, without departing from the scope of this application. The first acquisition module and the second acquisition module are both acquisition modules, but they are not the same acquisition module.

[0037] It should be noted that when an element is referred to as being “disposed on” another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0039] Magnetic resonance imaging (MRI) technology can directly produce transverse, sagittal, and coronal slice images, and has become a vital tool in clinical medical diagnosis and research, particularly for localizing tumors in patients undergoing radiotherapy. MRI systems use radiofrequency coils to transmit electromagnetic waves to excite human tissue, generating resonance signals that are picked up by receiving coils. The signals are then amplified and filtered by the receiving circuitry before being sent to a computer system for display.

[0040] The existing MRI imaging technology is a single-nuclide imaging technology, and the information contained in its imaging is relatively simple. However, the organism is a complex multi-molecular system. There are various forms and degrees of coupling between these multi-molecular nuclides. Therefore, there is an urgent need for a new imaging system to synchronously measure the nuclear magnetic resonance information of multiple nuclides, and provide more direct information and working principles in tumor cells for biological research and clinical medicine. For this reason, this application provides a multi-nuclide imaging method based on the multi-nuclide multi-frequency resonance principle. Taking into account both endogenous and exogenous nuclides, F, P, Na, and H signals can be collected to obtain biological information at different levels, and then the multi-molecular events of the tumor and related imaging factors can be analyzed to explore its intrinsic connection with the occurrence and development of tumors, and to comprehensively and systematically explain the laws of tumor occurrence and development, providing innovative research tools.

[0041] See Figure 1 The present application provides a multi-nuclide imaging method. The multi-nuclide imaging method includes:

[0042] S10 , applying a multi-frequency excitation pulse to the detection object to excite at least two nuclides in the detection object, wherein the at least two nuclides include a first nuclide and a second nuclide.

[0043] S20: Receive the magnetic resonance signal generated by the first nuclear species using the first coil 10, and receive the magnetic resonance signal generated by the second nuclear species using the second coil 30. The first coil and the second coil are placed in different temperature environments.

[0044] Optionally, the first nuclide is H and the second nuclide is X. X is one or more of Na, P, or F. The first coil 10 is placed in a room temperature environment, and the second coil 30 is placed in a low temperature environment. Optionally, the first coil is placed in an environment of 20°C to 30°C, and the second coil is placed in an environment of -248.15°C (25K) to -193.15°C (80K). In one practicable embodiment, the first coil is placed in an environment of 25°C. The second coil is placed in an environment of -243.15°C (30K).

[0045] In one embodiment, the detection object is human tissue. In another embodiment, the detection object is animal tissue. In yet another embodiment, the detection object is plant tissue.

[0046] There is no specific limitation on the manner of applying multi-frequency excitation pulses to the detection object, as long as at least two nuclides in the detection object can be excited. Optionally, when two nuclides in the detection object need to be excited, the imaging sequence needs to include radio frequency excitation pulses with Larmor frequencies of the two corresponding nuclides. The imaging sequence also needs to include encoding gradients. The encoding gradients may include layer selection gradients, phase encoding gradients, and frequency encoding gradients. In magnetic resonance imaging, when the detection object lies prone or supine on the scanning bed, the magnetic resonance signal can be phase-encoded using the gradient field in the front-to-back direction (i.e., the y direction), layer selection (or layer selection) encoding can be performed using the gradient field in the left-right direction (i.e., the x direction), and frequency encoding / frequency readout encoding can be performed using the gradient field in the up-down direction (i.e., the z direction).

[0047] In one embodiment, the multi-frequency excitation pulse is applied to the detection object using the first coil 10. In this case, the first coil 10 is a dual-frequency transmitting and receiving coil. The second coil 30 is a single-frequency receiving coil. In addition, the first coil 10 is used to transmit H nuclides and X nuclides. The first coil 10 is also used to receive H nuclides. The second coil 30 is used to receive X nuclides. Optionally, the first coil 10 is a dual-frequency birdcage coil. The dual-frequency birdcage coil can be formed by a single birdcage coil to form a dual frequency, including at least the X nuclide frequency in addition to H. For the specific structure, please refer to Figure 3 The inductor L3 and its parallel capacitor form an LC parallel circuit, which exhibits different impedance characteristics at different frequencies, thereby achieving dual-band detection. The first port and the second port are respectively input ports for different transmit powers. At the same time, the first port and the second port also serve as H-frequency receiving ports. It is understood that the first coil 10 can include a single coil unit to adapt to detection environments in small spaces. The first coil 10 can also be an array unit composed of multiple coil units.

[0048] In another embodiment, the first coil 10 is used to apply an H nucleus excitation pulse to the subject, and the second coil 30 is used to apply an X nucleus excitation pulse to the subject. In this case, the first coil 10 is a single-frequency transmitting and receiving coil, and its operating frequency is the H nuclide frequency. The second coil 30 is also a single-frequency transmitting and receiving coil, and its operating frequency is the X nuclide frequency. Optionally, the first coil 10 and the second coil 30 are single-frequency birdcage coils. It will be understood that the first coil 10 may comprise a single coil unit, or it may be an array unit composed of multiple coil units.

[0049] Placing the first coil 10 and the second coil 30 in different temperature environments, specifically placing the second coil 30 in a low-temperature environment, can reduce the noise inherent in the second coil 30, thereby reducing overall noise and, in turn, improving the overall SNR of the image. Furthermore, since H nuclei are present in high concentrations within the subject, the SNR requirement for imaging H nuclei is less stringent. Therefore, the first coil 10, maintained at room temperature, can be used to receive the magnetic resonance signals generated by these H nuclei. This combined imaging method of a room-temperature coil and a low-temperature coil enables dual-nuclide imaging. Since the low-temperature coil receives signals from only a single nuclide, tuning only for X nuclei is required. Furthermore, when the frequency deviates significantly from the H nuclei, there is no need to consider detuning circuits for the H nuclei's frequency, significantly reducing the technical complexity.

[0050] It is understandable that when imaging of more than two nuclides is required, the above method can still be used. In this case, it is only necessary to increase the number of the second coils 30 .

[0051] It is understood that the method of placing the second coil 30 in a low-temperature environment is not specifically limited. In one embodiment, the second coil 30 can be immersed in a cooling material so that the second coil 30 is in a low-temperature operating environment. In another embodiment, the cooling device 20 can be used to contact or approach the second coil 30 so that the second coil 30 is in a low-temperature operating environment. For details, please refer to Figure 2 , a cooler 21 is used to provide a cold fluid. The cold fluid can be a gas, a liquid, or a combination of a gas and a liquid. Of course, any existing technology for providing a cold fluid can be used, including but not limited to, physically transferring liquid helium from a storage dewar; cooling the helium flow with a closed-circuit refrigerator such as a Gifford-Mcmahon or Stirling refrigerator; or cooling using a Joule-Thomson refrigerator. The cold fluid flows through a thin, flexible, preferably metal delivery pipe to a cooling conductor 22 located near the second coil 30. The cooling conductor 22 is typically a block of heat-conducting material. For example, the cooling conductor 22 can be made of a highly thermally conductive non-metallic material (such as Al2O3). In one embodiment, the delivery pipe and the cooling conductor 22 are enclosed in a cold finger device.

[0052] The received magnetic resonance signals generated by the H nuclei and the X nuclei are sent to a reconstruction module for image reconstruction. The encoded data corresponding to the magnetic resonance signals is inserted into the K-space. This K-space is reconstructed to obtain imaging data for each target layer, and then the magnetic resonance images of each layer are reconstructed.

[0053] The multi-nuclide imaging method applies multi-frequency excitation pulses to the subject to excite at least two nuclides in the subject, including one H nucleus and one X nucleus. A first coil 10 receives the magnetic resonance signals generated by the H nuclei, while a second coil 30 receives the magnetic resonance signals generated by the X nuclei. The first coil 10 is placed in a room temperature environment, while the second coil 30 is placed in a low temperature environment. Because H nuclei are present in high concentrations within the subject, using the room temperature coil to receive the magnetic resonance signals generated by H nuclei and the low temperature coil to receive the magnetic resonance signals generated by X nuclei does not affect the imaging quality. Furthermore, the combined imaging method of the room temperature and low temperature coils enables dual-nuclide imaging. Since the low temperature coil only receives signals from a single nuclide, tuning only for the X nuclei is required. Furthermore, when the frequency deviates significantly from the H nuclei, there is no need to consider the detuning circuit for the H nuclei frequency, thus significantly reducing the technical difficulty.

[0054] See Figure 2 The present application provides a magnetic resonance coil assembly, which includes a first coil 10 and a second coil 30 .

[0055] The first coil 10 is used to receive magnetic resonance signals generated by H nuclei. The second coil 30 is used to receive magnetic resonance signals generated by X nuclei.

[0056] In one embodiment, the multi-frequency excitation pulse is applied to the detection object using the first coil 10. In this case, the first coil 10 is a dual-frequency transmitting and receiving coil. The second coil 30 is a single-frequency receiving coil. In addition, the first coil 10 is used to transmit H nuclides and X nuclides. The first coil 10 is also used to receive H nuclides. The second coil 30 is used to receive X nuclides. Optionally, the first coil 10 is a dual-frequency birdcage coil. The dual-frequency birdcage coil can be formed by a single birdcage coil to form a dual frequency, including at least the X nuclide frequency in addition to H. For the specific structure, please refer to Figure 3 The inductor L3 and its parallel capacitor form an LC parallel circuit, which exhibits different impedance characteristics at different frequencies, thereby achieving dual-band operation. The first port and the second port are respectively used as feed ports for different transmit powers. Simultaneously, the first port and the second port are also H-frequency receive ports. It is understood that the first coil 10 may include a single coil unit or an array unit composed of multiple coil units.

[0057] In another embodiment, the first coil 10 is used to apply an H nucleus excitation pulse to the subject, and the second coil 30 is used to apply an X nucleus excitation pulse to the subject. In this case, the first coil 10 is a single-frequency transmitting and receiving coil, and its operating frequency is the H nuclide frequency. The second coil 30 is also a single-frequency transmitting and receiving coil, and its operating frequency is the X nuclide frequency. Optionally, the first coil 10 and the second coil 30 are single-frequency birdcage coils. It will be understood that the first coil 10 may comprise a single coil unit, or it may be an array unit composed of multiple coil units.

[0058] Placing the first coil 10 and the second coil 30 in different temperature environments, specifically placing the second coil 30 in a low-temperature environment, can reduce the noise inherent in the second coil 30, thereby reducing overall noise and, in turn, improving the overall SNR of the image. Furthermore, since H nuclei are present in high concentrations within the subject, the SNR requirement for imaging H nuclei is less stringent. Therefore, the first coil 10, maintained at room temperature, can be used to receive the magnetic resonance signals generated by these H nuclei. This combined imaging method of a room-temperature coil and a low-temperature coil enables dual-nuclide imaging. Since the low-temperature coil receives signals from only a single nuclide, tuning only for X nuclei is required. Furthermore, when the frequency deviates significantly from the H nuclei, there is no need to consider detuning circuits for the H nuclei's frequency, significantly reducing the technical complexity.

[0059] It is understandable that when imaging of more than two nuclides is required, the above method can still be used. In this case, it is only necessary to increase the number of the second coils 30 .

[0060] In one embodiment, the magnetic resonance coil assembly further includes a cooling device 20. The cooling device 20 is used to keep the second coil 30 at a low temperature.

[0061] The method of placing the second coil 30 in a low temperature environment is not specifically limited. In one embodiment, the second coil 30 can be immersed in a cooling material so that the second coil 30 is in a low temperature operating environment. In another embodiment, the cooling device 20 can be used to contact or approach the second coil 30 so that the second coil 30 is in a low temperature operating environment. For details, please refer to Figure 2, using a cooler 21 to provide a cold fluid. The cold fluid can be a gas, a liquid, or a combination of a gas and a liquid. Of course, any existing technology for providing a cold fluid can be used, including but not limited to, physically transferring liquid helium from a storage dewar; cooling the helium flow with a closed-circuit refrigerator such as a Gifford-Mcmahon or Stirling refrigerator; or cooling with a Joule-Thomson refrigerator. The cold fluid flows through a thin, flexible, preferably metal delivery pipe to a cooling body 22 located near the second coil 30. The cooling body 22 is typically a block of heat-conducting material. For example, the cooling body 22 can be made of a highly thermally conductive non-metallic material (such as Al2O3). In one embodiment, the delivery pipe and the cooling body 22 are enclosed in a cold finger-like device. In one embodiment, the cooling device 20 further includes a housing 23. The cooler 21, the cooling body 22, and the second coil 30 are all placed in the housing 23. Optionally, an amplifier connected to the second coil 30 can also be disposed in the housing 23. Specifically, as Figure 2 As shown, the amplifier is provided on an amplifier board. The amplifier board is located in the housing 23. The amplifier is electrically connected to the second coil 30 via a wire. The amplifier is used to amplify the signal received by the second coil 30.

[0062] It is understood that the X nuclei may be other nuclides besides H nuclei. In one embodiment, the X nuclei are one or more of F, P, and Na. The manner of applying multi-frequency excitation pulses to the subject is not specifically limited, as long as at least two nuclides in the subject can be excited. Optionally, when two nuclides in the subject need to be excited, the imaging sequence needs to include radio frequency excitation pulses with Larmor frequencies of the two corresponding nuclides. The imaging sequence also needs to include encoding gradients. Encoding gradients may include slice selection gradients, phase encoding gradients, and frequency encoding gradients. In magnetic resonance imaging, when the subject is lying prone or supine on the scanning bed, the magnetic resonance signals can be phase encoded using a gradient field in the anterior-posterior direction (i.e., the y-direction), slice selection (or layer selection) encoding can be performed using a gradient field in the left-right direction (i.e., the x-direction), and frequency encoding / frequency readout encoding can be performed using a gradient field in the up-down direction (i.e., the z-direction).

[0063] The received magnetic resonance signals generated by the H nuclei and the X nuclei are sent to a reconstruction module for image reconstruction. The encoded data corresponding to the magnetic resonance signals is inserted into the K-space. This K-space is reconstructed to obtain imaging data for each target layer, and then the magnetic resonance images of each layer are reconstructed.

[0064] The magnetic resonance coil assembly described above utilizes a first coil 10 to receive magnetic resonance signals generated by H nuclei, and a second coil 30 to receive magnetic resonance signals generated by X nuclei. The first coil 10 is placed in a room temperature environment, while the second coil 30 is placed in a low temperature environment. Since H nuclei are present in high concentrations within the subject, using the room temperature coil to receive magnetic resonance signals generated by H nuclei and the low temperature coil to receive magnetic resonance signals generated by X nuclei does not affect imaging quality. Furthermore, the combined imaging method of room temperature and low temperature coils enables dual-nuclide imaging. Since the low temperature coil only receives signals from a single nuclide, tuning only for X nuclei is required. Furthermore, when the frequency deviates significantly from the H nuclei, there is no need to consider detuning circuits for the H nuclei frequency, thus significantly reducing technical difficulty.

[0065] The present application provides a multi-nuclide scanning device, comprising the magnetic resonance coil assembly according to any one of the above embodiments.

[0066] The object to be subjected to magnetic resonance imaging is referred to as a test object. In one embodiment, the test object is human tissue. In another embodiment, the test object is animal tissue. In yet another embodiment, the test object is plant tissue. The magnet in the scanning device can generate a static magnetic field applied to the test object. The static magnetic field can also be referred to as the main magnetic field. The main magnet can also control the uniformity of the static magnetic field.

[0067] The region of interest of the subject can be any part or tissue, such as the heart, blood vessels, or other organs or tissues with pulsating areas. The region of interest of the subject can be set by a computer. Each region of interest can be a three-dimensional block / three-dimensional volume. The three-dimensional block includes multiple two-dimensional slices.

[0068] The magnetic resonance coil assembly includes a first coil 10 , a cooling device 20 , and a second coil 30 .

[0069] The first coil 10 is used to receive magnetic resonance signals generated by H nuclei. The second coil 30 is in contact with or close to the cooling device 20 and is used to receive magnetic resonance signals generated by X nuclei.

[0070] In one embodiment, the multi-frequency excitation pulse is applied to the test object using the first coil 10. In this case, the first coil 10 is a dual-frequency transmitting and receiving coil. Optionally, the first coil 10 is a dual-frequency birdcage coil. The dual-frequency birdcage coil can be formed by a single birdcage coil to form a dual frequency, including at least the X nuclide frequency in addition to H. For a specific structure, please refer to Figure 3The inductor L3 and its parallel capacitor form an LC parallel circuit, which exhibits different impedance characteristics at different frequencies, thereby achieving dual-band operation. The first port and the second port are respectively used as feed ports for different transmit powers. Simultaneously, the first port and the second port are also H-frequency receive ports. It is understood that the first coil 10 may include a single coil unit or an array unit composed of multiple coil units.

[0071] In another embodiment, the first coil 10 is used to apply an H nucleus excitation pulse to the subject, and the second coil 30 is used to apply an X nucleus excitation pulse to the subject. In this case, the first coil 10 is a single-frequency transmitting and receiving coil, and its operating frequency is the H nuclide frequency. The second coil 30 is also a single-frequency transmitting and receiving coil, and its operating frequency is the X nuclide frequency. Optionally, the first coil 10 and the second coil 30 are single-frequency birdcage coils. It will be understood that the first coil 10 may comprise a single coil unit, or it may be an array unit composed of multiple coil units.

[0072] Placing the first coil 10 and the second coil 30 in different temperature environments, specifically placing the second coil 30 in a low-temperature environment, can reduce the noise inherent in the second coil 30, thereby reducing overall noise and, in turn, improving the overall SNR of the image. Furthermore, since H nuclei are present in high concentrations within the subject, the SNR requirement for imaging H nuclei is less stringent. Therefore, the first coil 10, maintained at room temperature, can be used to receive the magnetic resonance signals generated by these H nuclei. This combined imaging method of a room-temperature coil and a low-temperature coil enables dual-nuclide imaging. Since the low-temperature coil receives signals from only a single nuclide, tuning only for X nuclei is required. Furthermore, when the frequency deviates significantly from the H nuclei, there is no need to consider detuning circuits for the H nuclei's frequency, significantly reducing the technical complexity.

[0073] It is understandable that when imaging of more than two nuclides is required, the above method can still be used. In this case, it is only necessary to increase the number of the second coils 30 .

[0074] It is understood that the method of placing the second coil 30 in a low-temperature environment is not specifically limited. In one embodiment, the second coil 30 can be immersed in a cooling material so that the second coil 30 is in a low-temperature operating environment. In another embodiment, the cooling device 20 can be used to contact or approach the second coil 30 so that the second coil 30 is in a low-temperature operating environment. For details, please refer to Figure 2, using a cooler 21 to provide a cold fluid. The cold fluid can be a gas, a liquid, or a combination of a gas and a liquid. Of course, any existing technology for providing a cold fluid can be used, including but not limited to, physically transferring liquid helium from a storage dewar; cooling the helium flow with a closed-circuit refrigerator such as a Gifford-Mcmahon or Stirling refrigerator; or cooling using a Joule-Thomson refrigerator. The cold fluid flows through a thin, flexible, preferably metal delivery pipe to a cooling body 22 located near the second coil 30. The cooling body 22 is typically a block of heat-conducting material. For example, the cooling body 22 can be made of a highly heat-conducting non-metallic material (such as Al2O3). In one embodiment, the delivery pipe and the cooling body 22 are enclosed in a cold finger-like device. In one embodiment, the cooling device 20 further includes a housing 23. The cooler 21, the cooling body 22, and the second coil 30 are all placed in the housing 23.

[0075] It is understood that the X nuclei may be other nuclides besides H nuclei. In one embodiment, the X nuclei are one or more of F, P, and Na. The manner of applying multi-frequency excitation pulses to the subject is not specifically limited, as long as at least two nuclides in the subject can be excited. Optionally, when two nuclides in the subject need to be excited, the imaging sequence needs to include radio frequency excitation pulses with Larmor frequencies of the two corresponding nuclides. The imaging sequence also needs to include encoding gradients. Encoding gradients may include slice selection gradients, phase encoding gradients, and frequency encoding gradients. In magnetic resonance imaging, when the subject is lying prone or supine on the scanning bed, the magnetic resonance signals can be phase encoded using a gradient field in the anterior-posterior direction (i.e., the y-direction), slice selection (or layer selection) encoding can be performed using a gradient field in the left-right direction (i.e., the x-direction), and frequency encoding / frequency readout encoding can be performed using a gradient field in the up-down direction (i.e., the z-direction).

[0076] The received magnetic resonance signals generated by the H nuclei and the X nuclei are sent to a reconstruction module for image reconstruction. The encoded data corresponding to the magnetic resonance signals is inserted into the K-space. This K-space is reconstructed to obtain imaging data for each target layer, and then the magnetic resonance images of each layer are reconstructed.

[0077] The multi-nuclide scanning device utilizes a first coil 10 to receive magnetic resonance signals generated by H nuclei, and a second coil 30 to receive magnetic resonance signals generated by X nuclei. The first coil 10 is placed in a room temperature environment, while the second coil 30 is placed in a low temperature environment. Since H nuclei are present in high concentrations within the subject, using the room temperature coil to receive magnetic resonance signals generated by H nuclei and the low temperature coil to receive magnetic resonance signals generated by X nuclei does not affect imaging quality. Furthermore, the combined imaging method of room temperature and low temperature coils enables dual-nuclide imaging. Since the low temperature coil only receives signals from a single nuclide, tuning only for X nuclei is required. Furthermore, when the frequency deviates significantly from the H nuclei, there is no need to consider detuning circuits for the H nuclei frequency, significantly reducing technical difficulty.

[0078] The present application provides a multi-nuclide imaging system, including the multi-nuclide scanning device described in the above embodiments.

[0079] The present application provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the multi-nuclide imaging method described in any one of the above embodiments are implemented.

[0080] Memory, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to the multi-nuclide imaging method in the embodiments of the present application. The processor executes the software programs, instructions, and modules stored in the memory to perform various functional applications and data processing of the device, thereby implementing the multi-nuclide imaging method described above.

[0081] The memory may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system and applications required for at least one function. The data storage area may store data created based on the use of the terminal, etc. In addition, the memory may include a high-speed random access memory and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some instances, the memory may further include a memory remotely located relative to the processor, and these remote memories may be connected to the device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0082] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned 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.

[0083] The above-described embodiments merely represent several implementation methods of the present application. 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 a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A multi-nuclide imaging method, characterized in that: include: Applying a multi-frequency excitation pulse to a detection object to excite at least two nuclides in the detection object, wherein the at least two nuclides include a first nuclide and a second nuclide; Using a first coil to receive a magnetic resonance signal generated by the first nuclear species, and using a second coil to receive a magnetic resonance signal generated by the second nuclear species; Wherein, the first coil and the second coil are placed in different temperature environments; the first coil is placed in a normal temperature environment, and the second coil is placed in a low temperature environment.

2. The multi-nuclide imaging method according to claim 1, wherein: The first nuclide is H, and the second nuclide is other nuclide except H.

3. The multi-nuclide imaging method according to claim 2, characterized in that: The second nuclide includes Na, P or F; the first coil is placed in an environment of 20° C. to 30° C., and the second coil is placed in an environment of -248.15° C. to -193.15° C.

4. The multi-nuclide imaging method according to claim 1, wherein: applying the multi-frequency excitation pulse to the detection object using the first coil; Alternatively, a first nuclear species excitation pulse is applied to the detection object using the first coil, and a second nuclear species excitation pulse is applied to the detection object using the second coil.

5. A magnetic resonance coil assembly, characterized in that: include: a first coil, configured to receive a magnetic resonance signal generated by a first nuclear species in a first temperature environment; a second coil for receiving a magnetic resonance signal generated by a second nuclear species in a second temperature environment; The first temperature environment and the second temperature environment are different temperature environments; the first temperature environment is a normal temperature environment, and the second temperature environment is a low temperature environment.

6. The magnetic resonance coil assembly according to claim 5, wherein: The first nuclide is H, and the second nuclide is other nuclide except H.

7. The magnetic resonance coil assembly according to claim 6, wherein: The second nuclide includes Na, P or F; the first temperature environment is an environment of 20° C. to 30° C., and the second temperature environment is an environment of -248.15° C. to -193.15° C.

8. The magnetic resonance coil assembly according to claim 5, wherein: The first coil is a dual-frequency transmitting and receiving coil, and the second coil is a single-frequency receiving coil; Alternatively, the first coil is a single-frequency transmitting and receiving coil, and the second coil is a single-frequency transmitting and receiving coil.

9. A multi-nuclide scanning device, characterized in that: The magnetic resonance coil assembly comprises the magnetic resonance coil assembly according to any one of claims 5 to 8.

10. The multi-nuclide scanning device according to claim 9, characterized in that: A cooling device is also included, wherein the cooling device is used to keep the second coil in a second temperature environment.

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