Nuclear magnetic resonance imaging system and method
An open multi-nucleus imaging platform was constructed by using a multi-nucleus broadband spectrometer and nuclide coils, which solved the problems of limited information and high modification costs of existing magnetic resonance imaging systems, and realized non-invasive multi-nucleus imaging, improving scanning accuracy and flexibility.
Patent Information
- Application Number
- CN202511722390.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-21
- Publication Date
- 2026-02-27
AI Technical Summary
Existing magnetic resonance imaging systems mainly rely on hydrogen proton imaging, which cannot provide information on tissue metabolism, function, or biochemical environment. Furthermore, modifying commercial systems to achieve multi-nucleus imaging is costly and highly invasive.
An open multinucleus imaging platform is constructed by using a multinucleus broadband spectrometer, a switching controller, and nuclide coils. It is compatible with the original magnetic resonance system by utilizing synchronous trigger signals to achieve non-invasive multinucleus imaging and supports the simultaneous excitation and acquisition of radio frequency signals from at least two nuclides.
It improves the scanning accuracy of magnetic resonance imaging, enables non-invasive acquisition of biological information of multiple nuclides, is suitable for flexible imaging of multiple nuclides, and reduces the cost and risk of system modification.
Smart Images
Figure CN121578211A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of magnetic resonance imaging technology, and in particular to a nuclear magnetic resonance imaging system and method. BACKGROUND
[0002] Since the clinical application of magnetic resonance imaging (MRI) technology in the 1970s, hydrogen protons (1H) have long been relied on as the core imaging nuclide. Its technical advantage lies in the high abundance and strong magnetic sensitivity of hydrogen atoms in the human body, which can generate high-resolution anatomical structure images, and is irreplaceable in the detection of soft tissues such as brain tissue, joints, and spinal cord.
[0003] Therefore, most of the magnetic resonance imaging systems used in clinical practice are basically used for hydrogen nucleus imaging, and little consideration is given to imaging of nuclides other than hydrogen nuclei. Therefore, in system design, only the single resonance frequency of hydrogen protons is considered, and narrow-band transmission link components are used for signal excitation and reception.
[0004] However, there are two fundamental limitations of traditional hydrogen proton magnetic resonance imaging (1H-MRI): 1) single information dimension: only anatomical structure information can be provided, and changes in tissue metabolism, function or biochemical environment cannot be directly reflected; 2) bottleneck for early lesion detection: many lesions (such as neurodegenerative diseases and early tumors) have metabolic pathway disorders before physiological structure abnormalities appear, and 1H imaging is not sensitive enough to such changes. SUMMARY
[0005] The embodiments of the present application provide a nuclear magnetic resonance imaging system and method to compatible with magnetic resonance imaging of multiple atomic nuclei.
[0006] In a first aspect, the embodiments of the present application provide a nuclear magnetic resonance imaging system, comprising: a host computer, a multi-nuclear broadband spectrometer, a switching controller, a nuclide coil, and a magnetic resonance imaging system;
[0007] The host computer is in communication connection with the multi-nuclear broadband spectrometer, and is configured to send a control signal to the multi-nuclear broadband spectrometer; the multi-nuclear broadband spectrometer is configured to output a radio frequency excitation pulse according to the control signal; the nuclide coil is configured to output a radio frequency signal of a corresponding nuclide according to the radio frequency excitation pulse and receive an induced voltage signal; the magnetic resonance imaging system is configured to generate a main magnetic field passing through the nuclide coil; and the multi-nuclear broadband spectrometer and the magnetic resonance imaging system are clock-synchronized through a synchronization trigger signal.
[0008] The multi-nuclear broadband spectrometer is in communication connection with the switching controller, and is configured to send a first gate signal to the switching controller; and the switching controller is configured to switch between a transmission state and a reception state according to the first gate signal.
[0009] The switching controller is configured to transmit the induced voltage signal to the multi-nuclear broadband spectrometer in a receiving state; and the switching controller is configured to transmit the radio frequency excitation pulse to the nuclear species coil in a transmitting state.
[0010] In a second aspect, the embodiments of the present application further provide a method for nuclear magnetic resonance imaging, which is applicable to the nuclear magnetic resonance imaging system provided by any of the embodiments of the present application, and the method comprises a sequence of an excitation phase and an acquisition phase.
[0011] In the excitation phase, the host computer controls the multi-nuclear broadband spectrometer to output a first gating signal to the switching controller through a control signal, so that the radio frequency excitation pulse output by the multi-nuclear broadband spectrometer is transmitted to the nuclear species coil through the switching controller.
[0012] In the acquisition phase, the multi-nuclear broadband spectrometer is controlled to output a first gating signal to the switching controller, so that the induced voltage signal output by the nuclear species coil is transmitted to the multi-nuclear broadband spectrometer through the switching controller.
[0013] In the present application, an open multi-nuclear imaging platform is formed by combining the multi-nuclear broadband spectrometer and the original commercial nuclear magnetic resonance imaging system. The host computer can send a control signal to the multi-nuclear broadband spectrometer, the multi-nuclear broadband spectrometer outputs a radio frequency excitation pulse according to the control signal, the nuclear species coil outputs a radio frequency signal of the corresponding nuclear species according to the radio frequency excitation pulse, the magnetic resonance imaging system is used to generate a main magnetic field passing through the nuclear species coil, and a switching controller is further arranged between the multi-nuclear broadband spectrometer and the nuclear species coil. The multi-nuclear broadband spectrometer can send a first gating signal to the switching controller, so that the switching controller switches between a transmitting state and a receiving state. In the transmitting state, the switching controller transmits the radio frequency excitation pulse to the nuclear species coil, so as to excite the radio frequency signal. The radio frequency field formed by the radio frequency signal excites the proton spin and generates a rotating transverse magnetization in the patient's body. The transverse magnetization intensity is spatially encoded by the magnetic field gradient. In the receiving state, the nuclear species coil receives the above-mentioned transverse magnetization intensity and detects it as an induced voltage signal, and the nuclear species coil sends the induced voltage signal to the multi-nuclear broadband spectrometer. In the present embodiment, at least two nuclear species are excited by changing the radio frequency excitation pulse output by the multi-nuclear broadband spectrometer, and the multi-nuclear broadband spectrometer and the original magnetic resonance imaging system are clock-synchronized through a synchronous trigger signal. An external nuclear species imaging platform compatible with the original magnetic resonance system is non-invasively constructed, multi-nuclear imaging with zero risk is realized, and the scanning accuracy of the magnetic resonance imaging is improved. BRIEF DESCRIPTION OF DRAWINGS
[0014] Figure 1 FIG. 1 is a structural schematic diagram of a nuclear magnetic resonance imaging system provided by an embodiment of the present application;
[0015] Figure 2Another structural schematic diagram of a magnetic resonance imaging system provided by an embodiment of the present application is provided;
[0016] Figure 3 A flowchart of a synchronous trigger signal provided by an embodiment of the present application is provided;
[0017] Figure 4 Another flowchart of a synchronous trigger signal provided by an embodiment of the present application is provided;
[0018] Figure 5 Another flowchart of a synchronous trigger signal provided by an embodiment of the present application is provided;
[0019] Figure 6 A flowchart of a magnetic resonance imaging method provided by an embodiment of the present application is provided. 2 An imaging schematic diagram of H is provided.
[0020] Figure 7 A flowchart of a magnetic resonance imaging method provided by an embodiment of the present application is provided. DETAILED DESCRIPTION
[0021] The present application will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely intended for the purpose of interpretation of the present application and are not limiting of the present application. In addition, it should be noted that, for the purpose of description, only the parts related to the present application are shown in the accompanying drawings, rather than all the structures. The acquisition, storage, use, processing, etc. of data in the technical solution of the present application all comply with the relevant provisions of national laws and regulations.
[0022] Non-hydrogen nucleus imaging has significant value, and commercial clinical magnetic resonance imaging systems have begun to introduce clinical magnetic resonance systems supporting multi-nuclear imaging. However, the price of a commercial multi-nuclear imaging system is high. In order to realize non-hydrogen nucleus imaging on an existing device, the hardware of the existing magnetic resonance system must be replaced or expanded and modified. In addition to solving the problem of coil switching, the interface box, transmission and reception link and a series of components involved also need to be modified to support magnetic resonance multi-nuclear imaging. This often needs to be upgraded by the original manufacturer, which is expensive and limited to specific models. Therefore, due to cost / technical threshold, primary hospitals often cannot popularize it.
[0023] In order to realize non-hydrogen nucleus imaging without modifying the original system hardware structure, the prior art mainly adds a frequency conversion unit on the transmission and reception link of the coil, converts the hydrogen proton transmission frequency to the resonance frequency required for exciting non-hydrogen nuclei, and then converts the non-hydrogen nucleus receiving signal to the hydrogen proton receiving frequency, and receives and reconstructs it by the standard receiving link of the magnetic resonance imaging system. The advantage of this scheme is that it does not need to make big changes to the existing magnetic resonance imaging, only needs to add a frequency converter on the radio frequency link, and has good compatibility with the existing clinical magnetic resonance system.
[0024] However, the inventors discovered during the implementation of the embodiments of the present invention that the drawback of the method of adding frequency conversion units is that each nuclide requires a separate frequency converter, thus limiting its flexibility and scalability. Furthermore, because it occupies the hydrogen signal path during signal acquisition, simultaneous imaging of multiple nuclides is not possible. Moreover, since the multi-nucleus coil needs to be connected to the port of the commercial system bed, it is somewhat invasive and therefore requires original manufacturer permission; otherwise, there is a risk of violating the original MRI system warranty agreement.
[0025] To address the aforementioned issues, this invention provides a non-invasive external non-hydrogen nuclide imaging platform compatible with existing magnetic resonance imaging systems, enabling zero-risk multi-nucleus imaging and simultaneous excitation and acquisition of radio frequency signals from at least two nuclides. Figure 1 This is a schematic diagram of a magnetic resonance imaging system provided in an embodiment of the present invention. Figure 1 As shown, this embodiment of the invention provides a magnetic resonance imaging system, including: a host computer 11, a multi-core broadband spectrometer 12, a switching controller 13, a nuclide coil 14, and a magnetic resonance imaging system 15;
[0026] The host computer 11 is communicatively connected to the multi-core broadband spectrometer 12 and is used to send control signals to the multi-core broadband spectrometer 12; the multi-core broadband spectrometer 12 is used to output radio frequency excitation pulses according to the control signals; the nuclide coil 14 is used to output radio frequency signals of the corresponding nuclide according to the radio frequency excitation pulses and receive induced voltage signals; the magnetic resonance imaging system 15 is used to generate the main magnetic field passing through the nuclide coil 14; the multi-core broadband spectrometer 12 and the magnetic resonance imaging system 15 achieve clock synchronization through a synchronization trigger signal (e.g., a TTL synchronization signal);
[0027] The multi-core broadband spectrometer 12 is communicatively connected to the switching controller 13 and is used to send a first gating signal to the switching controller 13; the switching controller 13 is used to switch between the transmit state and the receive state according to the first gating signal.
[0028] The switching controller 13 is used to transmit the induced voltage signal to the multi-core broadband spectrometer 12 when in the receiving state; the switching controller 13 is used to transmit the radio frequency excitation pulse to the nuclide coil 14 when in the transmitting state.
[0029] In recent years, the field of medical imaging has turned its attention to non-hydrogen nuclei, seeking to obtain deeper biological information by detecting their distribution and metabolic state. For example, it can reveal changes in tissue metabolism, functional environment, or biochemical environment; or it can indicate whether metabolic pathways are disordered. Compared to hydrogen nuclei, non-hydrogen nuclei are more sensitive to lesion information, improving the precision and accuracy of lesion detection and enabling early screening. Representative nuclides and their clinical value include: deuterium (… 2 H): Hydrogen ( 1Isotopes of H are involved in metabolic processes, and their imaging allows for radiation-free dynamic tracking of glucose metabolism, which can be used for tumor detection and treatment efficacy evaluation; oxygen ( 17 O: can be used to assess tissue oxygenation and energy metabolism; carbon ( 13 C): It can monitor cellular metabolic flux in real time and can be used to monitor metabolic changes in cancer; phosphorus ( 31 P: Directly involved in cellular energy metabolism (ATP / creatine phosphate), its imaging can quantify tissue energy load in real time, and it is irreplaceable in assessing myocardial ischemia and tumor hypermetabolic processes; Sodium ( 23 Na: Concentration changes are related to cell membrane integrity and osmotic balance, and can be used to detect cerebral edema, tumor necrosis areas, and cartilage degeneration.
[0030] The multi-core broadband spectrometer 12 is used to receive and control the induced voltage signal from non-hydrogen nuclides via frequency excitation and radio frequency signals. The multi-core broadband spectrometer 12 has an internal timing control program for the radio frequency excitation pulse, which can output the radio frequency excitation pulse according to the control signal. Magnetic resonance imaging relies on a strong static magnetic field, the intensity of which is measured in tesla (T). Taking a model with a static magnetic field range of 5 T as an example, the broadband spectrometer supports a frequency range from 10 MHz to 130 MHz, covering the frequency range of this field strength. 17 O (28.48 MHz), 2 H (32.37 MHz), 13 C (53.5 MHz), 23 Na (56.3 MHz) and 31 The resonant frequency of P (86.2 MHz) can generate radio frequency signals from various non-hydrogen nuclides, thus the multi-nucleus broadband spectrometer 12 can be compatible with the excitation and acquisition of radio frequency signals from various non-hydrogen nuclides. The nuclide coil 14 can receive radio frequency excitation pulses and output radio frequency signals of the corresponding nuclides according to the radio frequency excitation pulses. In this embodiment, the nuclide coil 14 has the function of both transmitting radio frequency signals and receiving induced voltage signals. Specifically, the nuclide coil 14 generates radio frequency signals according to the radio frequency excitation pulses, and then the nuclide coil 14 generates a radio frequency field, which excites the proton spin and generates a rotating transverse magnetization in the patient's body. Then, the transverse magnetization intensity is spatially encoded by the magnetic field gradient and detected by the nuclide coil 14 as an induced voltage signal. The magnetic resonance imaging system 15 is an existing commercial clinical magnetic resonance imaging system, which can provide the main magnetic field passing through the nuclide coil 14, that is, the aforementioned static magnetic field. The multi-core broadband spectrometer 12 and the magnetic resonance imaging system 15 are connected by a synchronous trigger signal to enable the multi-core broadband spectrometer 12 and the existing commercial clinical magnetic resonance imaging system (magnetic resonance imaging system 15) to be used together. The execution timing of the multi-core broadband spectrometer 12 and the magnetic resonance imaging system 15 and other components is synchronized without modifying the system, keeping the system maintenance contract valid, so as to achieve multi-core synchronous data acquisition.
[0031] The switching controller 13 is also called a (T / R switching controller), and the switching controller 13 can switch between a transmitting (Tx) state and a receiving (Rx) state. In the receiving state, the switching controller 13 transmits the radio frequency excitation pulse output by the multi-nuclear broadband spectrometer 12 to the nuclear species coil 14, so as to excite the nuclear species coil 14 to generate a radio frequency signal; in the transmitting state, the switching controller 13 transmits the induced voltage signal output by the nuclear species coil 14 to the multi-nuclear broadband spectrometer 12, so that the multi-nuclear broadband spectrometer 12 collects the radio frequency signal. The multi-nuclear broadband spectrometer 12 can also send a first gate signal to the switching controller 13, so as to switch the switching controller 13 between the two transmission directions, thereby controlling the nuclear species coil 14 to switch between the transmitting state and the receiving state.
[0032] The nuclear magnetic resonance imaging system also includes a host computer 11, which is in communication connection with the multi-nuclear broadband spectrometer 12, and the host computer 11 can send a control signal to the multi-nuclear broadband spectrometer 12. Optionally, the host computer 11 can also be used to receive the induced voltage signal output by the multi-nuclear broadband spectrometer 12 and process image data to convert the induced voltage signal into image data, so as to facilitate an operator to more accurately analyze biological information according to the image data.
[0033] In the embodiment of the present application, an open multi-nuclear imaging platform is formed by combining the multi-nuclear broadband spectrometer and the original commercial nuclear magnetic resonance imaging system. The host computer can send a control signal to the multi-nuclear broadband spectrometer, the multi-nuclear broadband spectrometer outputs a radio frequency excitation pulse according to the control signal, the nuclear species coil outputs a radio frequency signal of a corresponding nuclear species according to the radio frequency excitation pulse, the magnetic resonance imaging system is used to generate a main magnetic field passing through the nuclear species coil, a switching controller is further arranged between the multi-nuclear broadband spectrometer and the nuclear species coil, and the multi-nuclear broadband spectrometer can send a first gate signal to the switching controller, so as to switch the switching controller between a transmitting state and a receiving state. In the transmitting state, the switching controller transmits the radio frequency excitation pulse to the nuclear species coil, so as to excite the radio frequency signal; the radio frequency field formed by the radio frequency signal excites the proton spin and generates a rotating transverse magnetization in the patient's body; the transverse magnetization intensity is spatially encoded by the magnetic field gradient; in the receiving state, the nuclear species coil receives the transverse magnetization and detects the induced voltage signal, and the nuclear species coil sends the induced voltage signal to the multi-nuclear broadband spectrometer. In the embodiment, at least two nuclear species are excited by changing the radio frequency excitation pulse output by the multi-nuclear broadband spectrometer, the multi-nuclear broadband spectrometer and the original magnetic resonance imaging system are clock-synchronized through a synchronous trigger signal, an external nuclear species imaging platform compatible with the original magnetic resonance system is non-invasively constructed, zero-risk multi-nuclear imaging is realized, and the scanning accuracy of the magnetic resonance imaging is improved.
[0034] The above is the core idea of the present application. The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0035] Optionally, the nuclide coil 14 can be a single-nuclide tuning coil or a multi-nuclide tuning coil. The single-nuclide tuning coil can realize the resonance frequency of a certain nuclide, and the multi-nuclide tuning coil can realize the resonance frequencies of multiple nuclides. Optionally, the nuclide coil 14 can be a single-channel coil or a multi-channel coil. When the nuclide coil 14 is a single-nuclide tuning coil, a single-channel coil with a simpler structure can be used, and when the nuclide coil 14 needs to be compatible with multiple nuclide resonance frequencies, a multi-channel coil can be used. The multi-channel coil can be provided with multiple plugs, and different combinations of plugs can correspond to nuclide coils of different nuclides. The tunable coil in the embodiment can realize the resonance frequencies of multiple different nuclides and be compatible with multiple atomic magnetic resonance imaging. Optionally, the nuclide coil 14 can be a birdcage coil or a surface coil. As a core component of the magnetic resonance imaging system, the design quality of the nuclide coil 14 has a crucial influence on the clarity and imaging speed of the magnetic resonance imaging. The nuclide coil 14 in the embodiment can be a birdcage coil, which has both transmitting and receiving functions and excellent radio frequency field uniformity; the nuclide coil 14 can also be a surface coil, which has a high signal-to-noise ratio, thereby greatly optimizing the imaging quality.
[0036] Optionally, the nuclide coil 14 can include multiple plugs; and the plugs of the nuclide coil 14 are pluggably connected to the ports of the switch controller 13. In the embodiment, the plugs of the nuclide coil 14 are pluggably connected to the ports of the switch controller 13, so that the radio frequency excitation pulse is loaded to the nuclide coil 14 after being switched by the switch controller 13, and the induced voltage signal carrying biological information or tissue information output by the nuclide coil 14 is received and transmitted to the multi-nuclear broadband spectrometer 12. In the embodiment, the pluggable connection can realize the replacement and upgrading of the nuclide coil 14 at any time, so as to be compatible with more nuclide radio frequency signals, and to replace the nuclide coil 14 that fails in time, thereby improving the reliability of the magnetic resonance imaging system.
[0037] Figure 2 Another structural schematic diagram of a magnetic resonance imaging system provided by the embodiment of the present application is shown in FIG. 6. Figure 2As shown, the nuclear magnetic resonance imaging system can further include: a power amplifier 16; the power amplifier 16 is respectively connected with the multi-nuclear broadband spectrometer 12 and the switching controller 13, and is used for power amplification processing of the radio frequency excitation pulse. The first input end of the power amplifier 16 is connected with the multi-nuclear broadband spectrometer 12, and is used for obtaining the first gate signal. Meanwhile, the multi-nuclear broadband spectrometer 12 also transmits the first gate signal to the switching controller 13. The second input end of the power amplifier 16 is connected with the radio frequency excitation pulse. The power amplifier 16 amplifies the radio frequency excitation pulse, and transmits the amplified radio frequency excitation pulse to the switching controller 13 through the output end of the power amplifier 16. Taking the model of the static magnetic field range of 5T as an example, the working frequency range of the power amplifier 16 covers 10-220MHz. The working frequency range covers the resonance frequencies of various different nuclear species under the field strength. It should be noted that the power amplifier 16 with the corresponding working frequency can be selected according to the frequency range of the resonance frequency of the required nuclear species, so as to adapt to different nuclear species. Of course, as shown in the embodiment, the power amplifier with the working frequency range covering various different nuclear species can also be selected. Optionally, the nuclear magnetic resonance imaging system can further include: a system power supply 17; the system power supply 17 is used for providing power supply for the host computer 11, the multi-nuclear broadband spectrometer 12, the switching controller 13 and the power amplifier 16.
[0038] With reference to the foregoing Figure 2 Optionally, the nuclear magnetic resonance imaging system can further include: a filter plate 18; the host computer 11, the multi-nuclear broadband spectrometer 12, the power amplifier 16 and the system power supply 17 are arranged on the first side of the filter plate 18; the switching controller 13 and the magnetic resonance imaging system 15 are arranged on the second side of the filter plate 18. The filter plate 18 divides the whole nuclear magnetic resonance imaging system into a scanning room and a magnet room, and separates the radio frequency path between the magnetic resonance imaging system and the multi-nuclear broadband spectrometer, so as to shield the interference between different systems and improve the accuracy of radio frequency signal detection.
[0039] With reference to the foregoing Figure 2 The magnetic resonance imaging system 15 can at least include: a magnetic resonance spectrometer 151, a magnet 152 and a gradient coil 153; the magnetic resonance spectrometer 151 is connected with the multi-nuclear broadband spectrometer 12, and is used for transmitting a synchronous trigger signal to the multi-nuclear broadband spectrometer 12; the magnet 152 is used for generating a main magnetic field passing through the nuclear species coil 14; the gradient coil 153 is arranged between the magnet 152 and the nuclear species coil 14; the magnetic resonance spectrometer 151 is connected with the gradient coil 153, and is used for outputting a second gate signal; the gradient coil 153 is used for generating a gradient field required for magnetic resonance imaging according to the second gate signal. The magnetic resonance imaging system 15 can be an original commercial magnetic resonance system, which includes the magnetic resonance spectrometer 151, the magnet 152 and the gradient coil 153, and is responsible for the control, frequency monitoring, shimming and 1H imaging. The magnetic resonance spectrometer 151 is communicatively connected with the multi-nuclear broadband spectrometer 12. The magnetic resonance spectrometer 151 can send a synchronization trigger signal (TTL synchronization signal) to the multi-nuclear broadband spectrometer 12, or the multi-nuclear broadband spectrometer 12 can send a synchronization trigger signal to the magnetic resonance spectrometer 151. In the embodiment, the trigger signal of the TTL is controlled by a software sequence, the clock of the original magnetic resonance system 15 and the two systems of the external X-nuclear (non-hydrogen nuclear) imaging platform are synchronized, the radio frequency of at least two kinds of nuclear species of hydrogen and X-nuclear are simultaneously excited, and the signals are simultaneously collected. The magnet 152 is used to generate a main magnetic field (static magnetic field) passing through the nuclear coil 14; the magnetic resonance spectrometer 151 also controls the gradient coil 153 to generate a gradient field required for magnetic resonance imaging through a second gate signal. The gradient coil 153 can generate a linear gradient magnetic field to make the magnetic resonance (MR) signals at different positions have different frequencies or phases, so as to realize the spatial positioning of the MR signals and the spatial positioning encoding of the magnetic resonance imaging MRI signals. In the embodiment, the multi-nuclear broadband spectrometer is used in combination with the original commercial magnetic resonance imaging system to open a multi-nuclear imaging platform, the execution timing of each component is synchronized by using a TTL signal, the system does not need to be modified, the system maintenance contract is valid, and real multi-nuclear synchronous data acquisition is realized.
[0040] In one specific example, first, the multi-nuclear broadband spectrometer receives a TTL trigger signal from a commercial magnetic resonance spectrometer, and then generates a radio frequency excitation pulse; synchronously, the multi-nuclear broadband spectrometer outputs a first gate signal to a power amplifier and a T / R switch controller; synchronously, the commercial spectrometer outputs a second gate signal to the gradient coil of the magnetic resonance imaging system, so that the gradient switch and switch are performed according to a specific sequence timing; specifically, the gradient modulation of the magnetic resonance imaging system is related to the positioning of the imaging area and the space-time encoding. The power amplifier receives the first gate signal from the multi-nuclear broadband spectrometer, starts to amplify the power of the radio frequency excitation pulse of the non-hydrogen nuclear species, sends it to the non-hydrogen nuclear coil through the T / R switch controller to realize the excitation of the non-hydrogen nuclear signal, and works according to a specific sequence timing.
[0041] As Figure 3 shown, Figure 3This is a schematic flowchart of a synchronous trigger signal provided in an embodiment of the present invention. During the excitation phase of the sequence timing, the multi-core broadband spectrometer outputs a first gate signal to the T / R switching controller, switching it to the Tx state. This allows the radio frequency excitation pulse output by the multi-core broadband spectrometer to be transmitted to the nuclide coil via the T / R switching controller. During the acquisition phase of the sequence timing, the multi-core broadband spectrometer outputs a first gate signal to the T / R switching controller, switching it to the Rx state. The sensing voltage signal of the non-hydrogen nuclei is returned to the multi-core broadband spectrometer from the non-hydrogen nuclei coil via the T / R switching controller, where it is acquired and stored by the analog-to-digital converter of the multi-core broadband spectrometer. Each excitation and acquisition phase forms a repetition time. Multiple repetition times can be included during the acquisition of the radio frequency signal to obtain a more accurate radio frequency signal.
[0042] It should be noted that this embodiment can also achieve 1 H and 2 Simultaneous imaging of H, Figure 4 This is a schematic diagram of another synchronous triggering signal provided in an embodiment of the present invention. Figure 5 This is a schematic diagram of another synchronous triggering signal provided in an embodiment of the present invention. Figure 4 and Figure 5 Implementation shown 1 H and 2 There are two methods for simultaneous H imaging. The first method is as follows: Figure 4 As shown, within one repetition time TR, the multi-nucleus broadband spectrometer and the magnetic resonance spectrometer simultaneously emit radio frequency excitation pulses ( 1 The excitation pulse of H is 1H RF and 2 The excitation pulse 2H (RF) of H is used, and the sensing voltage signal (1H signal and 2H signal) is acquired simultaneously. The second method, such as... Figure 5 As shown, within one repetition time TR, the magnetic resonance spectrometer first performs the excitation phase (emitting...). 1 The excitation pulse (1H RF) and acquisition phase (acquiring the 1H signal) are performed by the H-excitation phase, followed by the multi-core broadband spectrometer performing the excitation phase (emitting the 1H RF). 2 The invention utilizes a TTL synchronization mechanism to construct an external X-ray imaging platform compatible with the original MRI system without modifying the original MRI system (maintaining the validity of the system maintenance contract). The TTL trigger signal is controlled by software sequence to achieve clock synchronization between the two systems, enabling simultaneous radiofrequency excitation and signal acquisition of at least two radionuclides. It is small in size, flexible in application, suitable for large-scale clinical applications, and highly scalable, allowing free switching between multiple X-ray nuclei. Figure 6 As shown, Figure 6 Provided for embodiments of the present invention 2 A schematic diagram of the imaging of H.Figure 6 The middle right diagram shows magnetic resonance spectrum (MRS), and the left diagram shows spectral imaging (MRSI). The magnetic resonance spectrum shows spectrum, spectral fit, water, lipid and residual spectrum in turn. It can be seen that the spectrum has good signal-to-noise ratio, and the spectral imaging has better imaging effect.
[0043] In another example of the embodiment, if it is required to realize simultaneous imaging of H and H, the magnetic resonance spectrometer can output the excitation pulse 1H RF of H and receive the sensing voltage signal (1H signal), and the multi-nuclear broadband spectrometer can output the excitation pulse 2H RF of H and receive the sensing voltage signal (2H signal). 1 H and H, the magnetic resonance spectrometer can output the excitation pulse 1H RF of H and receive the sensing voltage signal (1H signal), and the multi-nuclear broadband spectrometer can output the excitation pulse 2H RF of H and receive the sensing voltage signal (2H signal). 2 H and H, the magnetic resonance spectrometer can output the excitation pulse 1H RF of H and receive the sensing voltage signal (1H signal), and the multi-nuclear broadband spectrometer can output the excitation pulse 2H RF of H and receive the sensing voltage signal (2H signal). 1 H and H, the magnetic resonance spectrometer can output the excitation pulse 1H RF of H and receive the sensing voltage signal (1H signal), and the multi-nuclear broadband spectrometer can output the excitation pulse 2H RF of H and receive the sensing voltage signal (2H signal). 1 H and H, the magnetic resonance spectrometer can output the excitation pulse 1H RF of H and receive the sensing voltage signal (1H signal), and the multi-nuclear broadband spectrometer can output the excitation pulse 2H RF of H and receive the sensing voltage signal (2H signal). 2 H and H, the magnetic resonance spectrometer can output the excitation pulse 1H RF of H and receive the sensing voltage signal (1H signal), and the multi-nuclear broadband spectrometer can output the excitation pulse 2H RF of H and receive the sensing voltage signal (2H signal). 1 H and H, the magnetic resonance spectrometer can output the excitation pulse 1H RF of H and receive the sensing voltage signal (1H signal), and the multi-nuclear broadband spectrometer can output the excitation pulse 2H RF of H and receive the sensing voltage signal (2H signal). 1 H and H, the magnetic resonance spectrometer can output the excitation pulse 1H RF of H and receive the sensing voltage signal (1H signal), and the multi-nuclear broadband spectrometer can output the excitation pulse 2H RF of H and receive the sensing voltage signal (2H signal). 1 H and H, the magnetic resonance spectrometer can output the excitation pulse 1H RF of H and receive the sensing voltage signal (1H signal), and the multi-nuclear broadband spectrometer can output the excitation pulse 2H RF of H and receive the sensing voltage signal (2H signal).
[0044] In summary, first, the nuclear magnetic resonance imaging system of the embodiment adopts a TTL synchronization mechanism, and a synchronization trigger signal can be sent by a magnetic resonance spectrometer of an original clinical magnetic resonance imaging system to synchronize a multi-nuclear broadband spectrometer; or a synchronization trigger signal can be sent by the multi-nuclear broadband spectrometer to the magnetic resonance spectrometer of the clinical magnetic resonance imaging system to realize timing synchronization, realize an open imaging platform; second, different frequency band power amplifiers can be used to adapt to more nuclei; finally, the open X-nuclear imaging can be realized by a filter board, a T / R switching controller is placed between the original clinical magnetic resonance imaging system magnet, or the T / R switching controller is integrated on other components of the multi-nuclear imaging platform without the filter board, to shield the interference between different systems.
[0045] Based on the same concept, the embodiment of the present application also provides a nuclear magnetic resonance imaging method suitable for the nuclear magnetic resonance imaging system provided by any embodiment of the present application. Figure 7 The flowchart of the nuclear magnetic resonance imaging method provided by the embodiment of the present application is shown in FIG. 4, and the nuclear magnetic resonance imaging method of the embodiment includes an excitation phase and a collection phase in turn, and the specific steps are as follows. Figure 7 The flowchart of the nuclear magnetic resonance imaging method provided by the embodiment of the present application is shown in FIG. 4, and the nuclear magnetic resonance imaging method of the embodiment includes an excitation phase and a collection phase in turn, and the specific steps are as follows.
[0046] Step S110, in the excitation phase, the host computer controls the multi-nuclear broadband spectrometer to output a first gating signal to the switching controller through a control signal, so that the radio frequency excitation pulse output by the multi-nuclear broadband spectrometer is transmitted to the nuclide coil through the switching controller.
[0047] Step S120, in the acquisition phase, the multi-nuclear broadband spectrometer is controlled to output the first gating signal to the switching controller, so that the induced voltage signal output by the nuclide coil is transmitted to the multi-nuclear broadband spectrometer through the switching controller.
[0048] It should be noted that the excitation phase and the acquisition phase constitute a repetition time, and the repetition time can be executed in turn for multiple times, and the number of cycles is not specially limited in the embodiment. Optionally, when simultaneous imaging of 1 H and 2 H is required, the excitation phase and the acquisition phase of 1 H and 2 H are coincided, or the excitation phase and the acquisition phase of 1 H are executed first, and then the excitation phase and the acquisition phase of 2 H are executed. In addition, the embodiment can also complete the simultaneous excitation and signal acquisition of three or more nuclides in one repetition time, and the embodiment does not specially limit this.
[0049] In the embodiment of the application, an open multi-nuclear imaging platform is formed by combining the multi-nuclear broadband spectrometer and the original commercial magnetic resonance imaging system. The host computer can send a control signal to the multi-nuclear broadband spectrometer, the multi-nuclear broadband spectrometer outputs a radio frequency excitation pulse according to the control signal, the nuclide coil outputs a radio frequency signal of the corresponding nuclide according to the radio frequency excitation pulse, the magnetic resonance imaging system is used to generate a main magnetic field passing through the nuclide coil, and a switching controller is further arranged between the multi-nuclear broadband spectrometer and the nuclide coil. The multi-nuclear broadband spectrometer can send a first gating signal to the switching controller, so that the switching controller switches between the transmitting state and the receiving state. In the transmitting state, the switching controller transmits the radio frequency excitation pulse to the nuclide coil to excite the radio frequency signal; the radio frequency field formed by the radio frequency signal excites the proton spin and generates a rotating transverse magnetization in the patient's body; the transverse magnetization intensity is spatially encoded by the magnetic field gradient; in the receiving state, the nuclide coil receives the above transverse magnetization intensity and detects it as an induced voltage signal, and the nuclide coil sends the induced voltage signal to the multi-nuclear broadband spectrometer. The embodiment realizes the excitation of the radio frequency of at least two nuclides by changing the radio frequency excitation pulse output by the multi-nuclear broadband spectrometer, non-invasively constructs an external nuclide imaging platform compatible with the original magnetic resonance system, realizes zero-risk multi-nuclear imaging, and thus improves the scanning accuracy of magnetic resonance imaging.
[0050] On the basis of the above-mentioned embodiments, the nuclear species coil is a multi-nuclear species tuning coil; the multi-nuclear species tuning coil is used at least to generate a first radio frequency signal corresponding to a first nuclear species and a second radio frequency signal corresponding to a second nuclear species; the multi-nuclear species tuning coil is also used to receive a first induced voltage signal corresponding to the first nuclear species and a second induced voltage signal corresponding to the second nuclear species; the multi-nuclear broadband spectrometer is used to output a first radio frequency excitation pulse for exciting the first radio frequency signal and a second radio frequency excitation pulse for exciting the second radio frequency signal; and the magnetic resonance imaging method specifically comprises a first excitation stage, a first acquisition stage, a second excitation stage, and a second acquisition stage; in the first excitation stage, the multi-nuclear broadband spectrometer is controlled to transmit the first radio frequency excitation pulse to the nuclear species coil through a switching controller; in the first acquisition stage, the nuclear species coil is controlled to transmit the first induced voltage signal to the multi-nuclear broadband spectrometer through the switching controller; in the second excitation stage, the multi-nuclear broadband spectrometer is controlled to transmit the second radio frequency excitation pulse to the nuclear species coil through the switching controller; and in the second acquisition stage, the nuclear species coil is controlled to transmit the second induced voltage signal to the multi-nuclear broadband spectrometer through the switching controller.
[0051] In the present embodiment, when excitation and signal acquisition of three nuclear species or more than three nuclear species are required, the multi-nuclear species tuning coil is used at least to generate a first radio frequency signal corresponding to a first nuclear species and a second radio frequency signal corresponding to a second nuclear species, and similarly, the multi-nuclear broadband spectrometer is used to output a first radio frequency excitation pulse for exciting the first radio frequency signal and a second radio frequency excitation pulse for exciting the second radio frequency signal. One repetition time can sequentially comprise a first excitation stage, a first acquisition stage, a second excitation stage, and a second acquisition stage. In the first excitation stage and the first acquisition stage, excitation and radio frequency acquisition of the first nuclear species are completed; and in the second excitation stage and the second acquisition stage, excitation and radio frequency acquisition of the second nuclear species are completed. The multi-nuclear species tuning coil in the present embodiment can simultaneously complete excitation and radio frequency acquisition of the first nuclear species and the second nuclear species, and synchronously, the magnetic resonance spectrometer can complete excitation and radio frequency acquisition of hydrogen nuclei, so that the magnetic resonance imaging system simultaneously completes excitation and detection of hydrogen nuclei, the first nuclear species (non-hydrogen nuclei), and the second nuclear species (non-hydrogen nuclei), thereby effectively improving the efficiency of magnetic resonance imaging.
[0052] Note that the above merely describes preferred embodiments of the present application and the principles of the applied technology. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of the present application. Therefore, although the present application has been described in detail through the above embodiments, the present application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.
Claims
1. A magnetic resonance imaging system, characterized in that, include: Host computer, multi-core broadband spectrometer, switching controller, nuclide coils and magnetic resonance imaging system; The host computer is communicatively connected to the multi-core broadband spectrometer and is used to send control signals to the multi-core broadband spectrometer. The multi-nucleus broadband spectrometer is used to output radio frequency excitation pulses according to the control signal; the nuclide coil is used to output radio frequency signals of the corresponding nuclide according to the radio frequency excitation pulses and receive induced voltage signals; the magnetic resonance imaging system is used to generate a main magnetic field passing through the nuclide coil; the multi-nucleus broadband spectrometer and the magnetic resonance imaging system are synchronized by a synchronization trigger signal. The multi-core broadband spectrometer is communicatively connected to the switching controller and is used to send a first gating signal to the switching controller; the switching controller is used to switch between a transmit state and a receive state according to the first gating signal. The switching controller is used to transmit the induced voltage signal to the multi-core broadband spectrometer when in the receiving state; The switching controller is used to transmit the radio frequency excitation pulse to the nuclide coil during the transmission state.
2. The nuclear magnetic resonance imaging system according to claim 1, characterized in that, The nuclide coil is a single-nuclide tuning coil or a multi-nuclide tuning coil.
3. The nuclear magnetic resonance imaging system according to claim 1, characterized in that, The nuclide coil includes multiple plugs; The plug of the nuclide coil is pluggable to the port of the switching controller.
4. The nuclear magnetic resonance imaging system according to claim 1, characterized in that, Also includes: Power amplifier; The power amplifier is communicatively connected to the multi-core broadband spectrometer, the switching controller, and the nuclide coil, respectively, and is used to amplify the power of the radio frequency excitation pulse.
5. The nuclear magnetic resonance imaging system according to claim 1, characterized in that, The multi-core broadband spectrometer is used to convert the induced voltage signal into a digital signal and transmit it to the host computer; the host computer is also used to process the digital signal to form image data.
6. The nuclear magnetic resonance imaging system according to claim 1, characterized in that, The magnetic resonance imaging system includes at least: a magnetic resonance spectrometer, a magnet, and a gradient coil; The magnetic resonance spectrometer is communicatively connected to the multi-nucleus broadband spectrometer and is used to send a synchronization trigger signal to the multi-nucleus broadband spectrometer; the magnet is used to generate a main magnetic field passing through the nuclide coil. The gradient coil is disposed between the magnet and the nuclide coil; the magnetic resonance spectrometer is communicatively connected to the gradient coil and is used to output a second gating signal; the gradient coil is used to generate the gradient field required for magnetic resonance imaging according to the second gating signal.
7. The nuclear magnetic resonance imaging system according to claim 4, characterized in that, Also includes: System power supply; The system power supply is used to provide power to the host computer, the multi-core broadband spectrometer, the switching controller, and the power amplifier.
8. The nuclear magnetic resonance imaging system according to claim 7, characterized in that, Also includes: Filter board; The host computer, the multi-core broadband spectrometer, the power amplifier, and the system power supply are located on the first side of the filter board; The switching controller and the magnetic resonance imaging system are located on the second side of the filter plate.
9. A method for nuclear magnetic resonance imaging, characterized in that, The method, applicable to the magnetic resonance imaging system according to any one of claims 1-8, comprises, in sequence, an excitation phase and an acquisition phase; During the excitation phase, the host computer controls the multi-core broadband spectrometer to output a first gating signal to the switching controller via a control signal, so that the radio frequency excitation pulse output by the multi-core broadband spectrometer is transmitted to the nuclide coil through the switching controller; During the acquisition phase, the multi-nucleus broadband spectrometer is controlled to output a first gating signal to the switching controller, so that the induced voltage signal output by the nuclide coil is transmitted to the multi-nucleus broadband spectrometer through the switching controller.
10. The nuclear magnetic resonance imaging method according to claim 9, characterized in that, The nuclide coil is a multi-nuclide tuning coil; the multi-nuclide tuning coil is at least used to generate a first radio frequency signal corresponding to a first nuclide and a second radio frequency signal corresponding to a second nuclide; the multi-nuclide tuning coil is also used to receive a first induced voltage signal corresponding to a first nuclide and a second induced voltage signal corresponding to a second nuclide; the multi-nuclide broadband spectrometer is used to output a first radio frequency excitation pulse to excite the first radio frequency signal and a second radio frequency excitation pulse to excite the second radio frequency signal. The nuclear magnetic resonance imaging method specifically includes, in sequence: a first excitation stage, a first acquisition stage, a second excitation stage, and a second acquisition stage; In the first excitation phase, the multi-nucleus broadband spectrometer is controlled to transmit the first radio frequency excitation pulse to the nuclide coil through the switching controller; in the first acquisition phase, the nuclide coil is controlled to transmit the first induced voltage signal to the multi-nucleus broadband spectrometer through the switching controller. In the second excitation phase, the multi-nucleus broadband spectrometer is controlled to transmit the second radio frequency excitation pulse to the nuclide coil through the switching controller; in the second acquisition phase, the nuclide coil is controlled to transmit the second induced voltage signal to the multi-nucleus broadband spectrometer through the switching controller.