Magnetic resonance imaging system and transmitting device, transmitting method

Abstract

The embodiment of the present application provides a kind of magnetic resonance imaging system and transmitting device, transmitting method.The method comprises: generating and outputting pulse signal by transmitting controller;The pulse signal is amplified by radio frequency amplifier;The signal amplified by radio frequency amplifier is transmitted to the transmitting coil of the magnetic resonance imaging system by signal processor;According to the bandwidth data of the transmitting controller, the radio frequency amplifier and the signal processor, frequency offset lookup information for bandwidth compensation to entire transmitting device is generated;The frequency offset lookup information is used to control the transmitting controller to generate output power.Thereby, not only can the digital predistortion processing of power amplifier be carried out using the frequency offset lookup information, but also the bandwidth performance of entire transmitting device can be improved, and the quality of magnetic resonance image is improved.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a magnetic resonance imaging system, a transmitting device, and a transmitting method. Background Technology

[0002] Magnetic Resonance Imaging (MRI) systems are widely used in medical diagnostics. An MRI system typically includes a main magnet, a gradient radio frequency amplifier, gradient coils, a transmitter chain module, transmitter / receiver coils, and a receiver chain module. The transmitter chain module generates pulse signals that are transmitted to the transmitter / receiver coils. These coils then generate radio frequency excitation signals to excite the scanned object, producing a magnetic resonance signal. After excitation, the transmitter / receiver coils receive the magnetic resonance signal and reconstruct medical parameter images based on this signal.

[0003] In magnetic resonance transmitter chain modules, forward power, reverse power, voltage standing wave ratio (VSWR), return loss, and radio frequency energy absorption ratio (SAR) are all important reference indicators. Among them, VSWR reflects the RF load matching condition, return loss represents the ratio of the reflected power of the RF input signal to the input signal power, which also reflects the RF load matching condition, and SAR represents the ratio of the RF signal absorbed by the scanned object. Summary of the Invention

[0004] Currently, the transmitter of a magnetic resonance imaging (MRI) system can include a transmitter controller, a radio frequency amplifier, and a signal processor. However, the inventors have discovered that the bandwidth data of each component in the current transmitter is set separately. Even if the bandwidth data of each component is relatively good, such as + / -650kHz (+ / -0.25dB) or + / -500kHz, the bandwidth data of the entire transmitter is still poor, for example, only + / -250kHz. This significantly affects the performance of the transmitter and reduces the quality of the MRI images.

[0005] To address at least one of the aforementioned technical problems, embodiments of this application provide a magnetic resonance imaging system, a transmitting device, and a transmitting method.

[0006] According to one aspect of the embodiments of this application, a method for transmitting a magnetic resonance imaging system is provided, comprising:

[0007] The pulse signal is generated and output by the transmit controller;

[0008] The pulse signal is amplified by a radio frequency amplifier;

[0009] The signal processor transmits the amplified signal from the radio frequency amplifier to the transmitting coil of the magnetic resonance imaging system.

[0010] Based on the bandwidth data of the transmitter controller, the radio frequency amplifier, and the signal processor, frequency offset lookup information is generated for bandwidth compensation of the entire transmitter; the frequency offset lookup information is used to control the transmitter controller to generate output power.

[0011] In some embodiments, the bandwidth data of the transmit controller, the RF amplifier, and the signal processor are pre-generated according to a standard load, and the bandwidth data of the transmit controller, the RF amplifier, and the signal processor are pre-stored in their respective memories.

[0012] In some embodiments, the method further includes:

[0013] When the transmit controller, the RF amplifier, and the signal processor are integrated and initialized, the bandwidth data of the transmit controller, the RF amplifier, and the signal processor are obtained from their respective memories.

[0014] In some embodiments, the method further includes:

[0015] During the pre-scan phase, multiple training pulse signals modulated at different frequencies across the full bandwidth are generated for a specific load.

[0016] The frequency offset lookup information is updated for the first time based on the plurality of training pulse signals.

[0017] In some embodiments, the method further includes:

[0018] During the scanning phase, for the specific load, the direct digital frequency synthesizer in the transmit controller generates output power based on the first updated frequency offset lookup information.

[0019] In some embodiments, the method further includes:

[0020] The frequency offset lookup information is updated a second time based on a predetermined load or a load determined through machine learning.

[0021] In some embodiments, the method further includes:

[0022] During the scanning phase, for a specific load, the transmit controller generates output power based on the second updated frequency offset lookup information.

[0023] In some embodiments, the method further includes:

[0024] Determine whether a specific load is the same as or similar to a pre-determined load or a load determined by machine learning;

[0025] Under the same or similar circumstances, during the scanning phase for the specific load, the transmit controller generates output power based on the second updated frequency offset lookup information.

[0026] In some embodiments, where they are not the same or dissimilar

[0027] During the pre-scanning phase, for the specific load, multiple training pulse signals modulated at different frequencies across the full bandwidth are generated, and the frequency offset lookup information is updated for the first time based on the multiple training pulse signals; and

[0028] During the scanning phase, for the specific load, the transmit controller generates output power based on the first updated frequency offset lookup information.

[0029] According to another aspect of the embodiments of this application, a transmitting device for a magnetic resonance imaging system is provided, comprising:

[0030] A transmitter controller, used to generate and output pulse signals;

[0031] A radio frequency amplifier, used to amplify the pulse signal;

[0032] A signal processor, which is used to transmit the signal amplified by the radio frequency amplifier to the transmitting coil of the magnetic resonance imaging system;

[0033] The bandwidth compensation unit generates frequency offset lookup information for bandwidth compensation of the entire transmitting device based on the bandwidth data of the transmit controller, the RF amplifier, and the signal processor; the frequency offset lookup information is used to control the transmit controller to generate output power.

[0034] In some embodiments, the bandwidth data of the transmit controller, the RF amplifier, and the signal processor are pre-generated according to a standard load, and the bandwidth data of the transmit controller, the RF amplifier, and the signal processor are pre-stored in their respective memories.

[0035] In some embodiments, when the transmit controller, the RF amplifier, and the signal processor are integrated and initialized, the bandwidth compensation unit obtains the bandwidth data of the transmit controller, the RF amplifier, and the signal processor from their respective memories.

[0036] In some embodiments, during the pre-scan phase for a specific load, the transmit controller generates multiple training pulse signals modulated at different frequencies across the full bandwidth, and the bandwidth compensation unit further updates the frequency offset lookup information based on the multiple training pulse signals.

[0037] In some embodiments, during the scanning phase for the specific load, the transmit controller generates output power based on the first updated frequency offset lookup information.

[0038] In some embodiments, the bandwidth compensation unit further updates the frequency offset lookup information a second time based on a predetermined load or a load determined by machine learning.

[0039] In some embodiments, during the scanning phase, for a specific load, the transmit controller generates output power based on the second updated frequency offset lookup information.

[0040] In some embodiments, the transmission controller further determines whether a particular load is the same as or similar to a predetermined load or a load determined by machine learning;

[0041] Under the same or similar circumstances, during the scanning phase for the specific load, the transmit controller generates output power based on the second updated frequency offset lookup information.

[0042] In some embodiments, where they are not identical or similar, the transmit controller generates multiple training pulse signals modulated at different frequencies across the full bandwidth for the specific load during the pre-scan phase, and the bandwidth compensation unit further updates the frequency offset lookup information based on the multiple training pulse signals; and during the scan phase, for the specific load, the transmit controller generates output power based on the first updated frequency offset lookup information.

[0043] According to another aspect of the embodiments of this application, a magnetic resonance imaging system is provided, the system comprising:

[0044] Transmitting coil; and

[0045] The launching device as described above.

[0046] According to another aspect of the embodiments of this application, a storage medium storing a computer-readable program is provided, characterized in that the computer-readable program causes a computer to perform the transmission method as described above in a device.

[0047] One of the beneficial effects of the embodiments of this application is that frequency offset lookup information for bandwidth compensation of the entire transmitting device is generated based on the bandwidth data of the transmit controller, RF amplifier, and signal processor. Therefore, not only can this frequency offset lookup information be used for digital predistortion processing of the power amplifier, but the bandwidth performance of the entire transmitting device can also be improved, and the quality of magnetic resonance images can be enhanced.

[0048] Referring to the following description and accompanying drawings, specific implementation methods of the embodiments of this application are disclosed in detail, indicating how the principles of the embodiments of this application can be adopted. It should be understood that the implementation methods of this application are not limited in scope. Within the spirit and scope of the appended claims, the implementation methods of this application include many changes, modifications, and equivalents. Attached Figure Description

[0049] The accompanying drawings, which form part of the specification, are used to provide a further understanding of the embodiments of this application and illustrate the implementation methods of this application, together with the textual description, to explain the principles of this application. Obviously, the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other implementation methods based on these drawings without creative effort. In the drawings:

[0050] Figure 1 This is a schematic diagram of the transmitting device of a magnetic resonance imaging system;

[0051] Figure 2 This is a schematic diagram of the emission method of the magnetic resonance imaging system according to an embodiment of this application;

[0052] Figure 3 This is a schematic diagram of the transmitting device of a magnetic resonance imaging system according to an embodiment of this application;

[0053] Figure 4 This is a schematic diagram illustrating the relationship between frequency and deviation in an embodiment of this application;

[0054] Figure 5 This is an example diagram of a training pulse signal according to an embodiment of this application;

[0055] Figure 6 This is a schematic diagram of the transmitting device of a magnetic resonance imaging system according to an embodiment of this application;

[0056] Figure 7 This is a schematic diagram of a magnetic resonance imaging system according to an embodiment of this application. Detailed Implementation

[0057] Referring to the accompanying drawings, the foregoing and other features of the embodiments of this application will become apparent from the following description. Specific embodiments of this application are specifically disclosed in the description and drawings, illustrating partial implementations in which the principles of the embodiments of this application can be adopted. It should be understood that this application is not limited to the described embodiments; rather, the embodiments of this application include all modifications, variations, and equivalents falling within the scope of the appended claims.

[0058] In the embodiments of this application, the terms "first," "second," etc., are used to distinguish different elements by name, but do not indicate the spatial arrangement or chronological order of these elements, and these elements should not be limited by these terms. The term "and / or" includes any one or more of the terms listed in association and all combinations thereof. The terms "comprising," "including," "having," etc., refer to the presence of the stated features, elements, components, or assemblies, but do not exclude the presence or addition of one or more other features, elements, components, or assemblies.

[0059] In the embodiments of this application, the singular forms "a," "the," etc., including the plural forms, should be broadly understood as "a kind" or "a class" rather than limited to the meaning of "an." Furthermore, the term "the" should be understood to include both the singular and plural forms, unless the context explicitly indicates otherwise. Additionally, the term "according to" should be understood as "at least partially based on…," and the term "based on" should be understood as "at least partially based on…," unless the context explicitly indicates otherwise.

[0060] Features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments. The term "comprising / including" as used herein means the presence of a feature, integral, step, or component, but does not exclude the presence or addition of one or more other features, integrals, steps, or components.

[0061] The following section will first explain the transmitting device of the MRI system.

[0062] Figure 1 This is a schematic diagram of the transmitting device of a magnetic resonance imaging system, such as... Figure 1 As shown, the device 100 includes: a transmit controller (also referred to as a transmit control engine, transmit control module / unit, etc.) 101, which generates and outputs a pulse signal; a radio frequency amplifier (also referred to as a radio frequency module / unit, etc.) 102, which amplifies the pulse signal; and a signal processor (also referred to as an output module / unit, etc.) 103, which transmits the signal amplified by the radio frequency amplifier 102 to the transmit coil 104 of the magnetic resonance imaging system. Furthermore, as... Figure 1As shown, the signal processor 103 can receive and adjust the phase of the feedback signal, and output the phase-adjusted feedback signal to the transmission controller 101.

[0063] like Figure 1 As shown, the transmit controller 101 may include a direct digital frequency synthesizer (DDS) 1011, a digital-to-analog converter (DAC) 1012, and a radio frequency front-end circuit 1013. The transmit controller 101 generates the required scan sequence (including radio frequency pulse signals) during an MRI scan according to an instruction or command. These pulse signals can generate a radio frequency field to excite the longitudinal magnetization vector of the scanned object to reverse, thereby generating a transverse magnetization vector. This transverse magnetization vector attenuates spirally around an external magnetic field at a fixed angular frequency to generate a free-induced attenuation signal. The magnetic resonance signal used for imaging can be obtained from this induced attenuation signal.

[0064] The transmitter controller 101 typically generates a low-power radio frequency pulse signal; the transmitter controller 101 is connected to the radio frequency amplifier 102 and inputs the pulse signal into the radio frequency amplifier 102. The type of the scan sequence can be determined as needed, and this application embodiment does not limit it.

[0065] Optionally, the RF front-end circuit 1013 may also include a transmit attenuator (not shown) for controlling the degree to which the pulse signal is attenuated before being input to the RF amplifier 102. Specific embodiments of the transmit controller 101 described above can be found in related technologies, but this application is not intended to limit them.

[0066] The radio frequency amplifier 102 is used to receive the low-power radio frequency pulse signal output by the transmitter controller 101, amplify it, and then output the amplified radio frequency pulse signal. The radio frequency amplifier 102 can process the received radio frequency pulse signal to output a high-power radio frequency pulse signal, thereby meeting the imaging requirements of the magnetic resonance imaging system. The structure and type of the radio frequency amplifier 102 can be referred to in relevant technologies, and will not be listed here.

[0067] The signal processor 103 transmits the amplified signal from the radio frequency amplifier 102 to the transmit coil 104 of the magnetic resonance imaging system and outputs a feedback signal to the transmit controller 101. Optionally, the signal processor 103 may include a transmit / receive mode switch (not shown), which is controlled by a pulse signal from the transmit controller 101 to electrically connect the radio frequency amplifier 102 to the transmit coil of the magnetic resonance imaging system during transmit mode; in addition, the signal processor 103 also receives a portion of the reflected signal generated by the scanned object.

[0068] Signal processor 103 outputs a feedback signal to the transmit controller 101, the feedback signal including a forward feedback signal (e.g., Figure 1 (fwd) and / or reverse feedback signal (e.g. Figure 1 The forward feedback signal is the signal directly output by the signal processor 103, that is, the feedback signal at the front end of the transmitting coil; the reverse feedback signal is the signal returned from the transmitting coil after the radio frequency pulse signal is amplified and reaches the transmitting coil, that is, the feedback signal at the rear end of the transmitting coil.

[0069] The above provides a schematic description of the transmitting device of the MRI system. However, this application is not limited thereto. For example, the various components can be appropriately adjusted, and additional components can be added or some components can be removed. Those skilled in the art can make appropriate modifications based on the above description, and are not limited to the above-described components. Figure 1 The records.

[0070] The inventors discovered that the bandwidth data of each component of the current transmitting device is set separately. Even if the bandwidth data of each component is good, the bandwidth data of the entire transmitting device may still be poor, which greatly affects the performance of the transmitting device and reduces the quality of magnetic resonance images.

[0071] In addition, the subjects being examined by an MRI system may vary, such as weight, height, and body shape, resulting in significant variations in the load on the MRI system. However, these variations in the load on the MRI system can lead to significant differences in the bandwidth of the transmitting device, thereby affecting the performance of the transmitting device and reducing the quality of the magnetic resonance images.

[0072] To address at least one of the above-mentioned problems, the embodiments of this application are described in detail below.

[0073] First aspect of the embodiments

[0074] This application provides a method for transmitting a magnetic resonance imaging system. Figure 2 This is a schematic diagram of the emission method of the magnetic resonance imaging system according to an embodiment of this application, as shown below. Figure 2 As shown, the launch method includes:

[0075] 201. Based on the bandwidth data of the transmitter controller, RF amplifier, and signal processor, frequency offset lookup information is generated for bandwidth compensation of the entire transmitter; the frequency offset lookup information is used to control the transmitter controller to generate output power.

[0076] like Figure 2 As shown, the launch method also includes:

[0077] 202, a pulse signal is generated and output by the transmit controller;

[0078] 203, The pulse signal is amplified by a radio frequency amplifier;

[0079] 204. The signal processor transmits the signal amplified by the radio frequency amplifier to the transmitting coil of the magnetic resonance imaging system.

[0080] It is worth noting that the above appendix Figure 2 The embodiments of this application have only been illustrated schematically, and the application is not limited thereto. For example, the execution order between various operations can be appropriately adjusted, and other operations can be added or some operations can be removed. Those skilled in the art can make appropriate modifications based on the above description, and are not limited to the above-described embodiments. Figure 2 The records.

[0081] Therefore, based on the bandwidth data of the transmit controller, RF amplifier, and signal processor, frequency offset lookup information is generated for bandwidth compensation of the entire transmit device. This improves the bandwidth performance of the entire transmit device and enhances the quality of magnetic resonance imaging.

[0082] In some embodiments, the bandwidth data of the transmit controller, RF amplifier, and signal processor are pre-generated according to a standard load, and the bandwidth data of the transmit controller, RF amplifier, and signal processor are pre-stored in their respective memories.

[0083] For example, the transmit controller, RF amplifier, and signal processor are supplied by different vendors. Each vendor can pre-generate its own bandwidth data based on a standard load (e.g., 50 Ohms). Specific details of the bandwidth data can be found in relevant technical documents. Each vendor can store the bandwidth data separately in the memory (e.g., EEPROM) of each component.

[0084] In some embodiments, when the transmit controller, the RF amplifier, and the signal processor are integrated and initialized, bandwidth data of the transmit controller, the RF amplifier, and the signal processor are obtained from their respective memories.

[0085] For example, a processing module in the transmitter controller can read bandwidth data from the EEPROM of each component and generate frequency offset lookup information, such as a LUT (Look-Up Table), for bandwidth compensation of the entire transmitter. This LUT can assign different coefficients to multiple frequencies across the full bandwidth of the transmitter to ensure that the performance of the entire transmitter meets the requirements.

[0086] For example, a LUT is a two-dimensional table of (frequency, coefficients), where each frequency corresponds to a coefficient used for bandwidth compensation, and the initial values ​​of these coefficients can be set to default values. When generating this LUT table, the transmit controller, RF amplifier, and signal processor can be integrated and initialized. The specific values ​​of the LUT are then adjusted to target the ideal (or satisfactory) frequency response of the entire transmitting device, thereby obtaining an LUT corresponding to the ideal output characteristics. For details on the specific content of LUTs and how to generate them, please refer to relevant technologies.

[0087] Figure 3 This is a schematic diagram of the transmitting device of a magnetic resonance imaging system according to an embodiment of this application, as shown below. Figure 3 As shown, the transmitting device 300 includes: a transmitting controller 301 for generating and outputting a pulse signal; a radio frequency amplifier 302 for amplifying the pulse signal; and a signal processor 303 for transmitting the amplified signal from the radio frequency amplifier 302 to the transmitting coil 304 of the magnetic resonance imaging system. Furthermore, as... Figure 3 As shown, the signal processor 303 can receive and adjust the phase of the feedback signal, and output the phase-adjusted feedback signal to the transmission controller 101.

[0088] like Figure 3 As shown, bandwidth data of the transmitter controller 301, the RF amplifier 302, and the signal processor 303 can be read from their respective EEPROMs. Based on this data, a bandwidth compensation unit (LUT) 3014 is generated for bandwidth compensation of the entire transmitter device 300. Certain components or modules in the transmitter controller 301 (e.g., DDS 3011) can generate output power based on this LUT 3014.

[0089] Figure 4 This is a schematic diagram illustrating the relationship between frequency and deviation in an embodiment of this application. Figure 4 As shown, by using the frequency offset lookup information of this application embodiment, the entire transmitting device has better performance.

[0090] The above explanation uses the example of pre-storing bandwidth data for each component, but this application is not limited to this. For example, suppliers may also store the bandwidth data of each component on a medium separate from the component (such as an optical disc or storage medium), or place it on a specific server on the network, or transmit it to the integrator via communication tools, etc.

[0091] Furthermore, the generation and updating of frequency offset lookup information can be implemented by the transmit controller (e.g., a module integrated into the transmit controller) or by other devices separate from the transmit controller. The frequency offset lookup information can be stored in the transmit controller or in other devices separate from the transmit controller. The memory can be EEPROM or any other arbitrary storage medium.

[0092] The above provides an illustrative explanation of the generation of frequency offset lookup information, using a LUT as an example. This application is not limited to this; other data structures can also be used for the frequency offset lookup information. By using this frequency offset lookup information, the overall performance of the integrated components of the transmitter can be adjusted. With good bandwidth data for each component, the entire transmitter can achieve better performance.

[0093] In some embodiments, during the pre-scanning phase, multiple training pulse signals modulated at different frequencies across the full bandwidth are generated for a specific load, and the frequency offset lookup information is first updated based on the multiple training pulse signals.

[0094] For example, for a specific object to be detected (a specific load), an automatic pre-scan (APS) can be performed before the formal scan. The transmit controller can adjust the frequency offset across the entire operating bandwidth, for example, from -650 kHz to +650 kHz. The TCE can generate multiple training pulse signals at these frequencies and capture forward power samples to optimize the LUT for that specific load.

[0095] Figure 5 This is an example diagram of a training pulse signal according to an embodiment of this application. Figure 5 As shown, training pulse signals can be generated at positions with frequency offsets of -650, -625, -600, ..., 0, ... 600, 625, 650. The frequency offset lookup information is then updated based on these training pulse signals (this can be called dynamic updating).

[0096] In some embodiments, during the scanning phase for the specific load, the transmit controller (e.g., the direct digital frequency synthesizer therein) generates output power based on a first updated frequency offset lookup information.

[0097] Therefore, updating the frequency offset lookup information for each specific load can eliminate or reduce the impact of load differences on the bandwidth of the transmitting device, thereby further improving the performance of the transmitting device and enhancing the quality of magnetic resonance images.

[0098] In some embodiments, the frequency offset lookup information is updated a second time based on a predetermined load or a load determined by machine learning.

[0099] For example, in certain scenarios, the subjects to be detected are relatively consistent and can be predetermined. For instance, in a children's hospital or pediatric ward, the subjects are relatively easy to classify, so several typical loads can be predetermined. For example, children aged 3-8 are classified as the first type of load, children aged 9-12 as the second type of load, and so on. Based on these predetermined loads, the frequency offset lookup information can be updated in advance (this can be called semi-static pre-update).

[0100] For example, machine learning can be used to statistically analyze the detected objects. For instance, by statistically analyzing various parameters of an MRI system under different loads, typical loads can be determined. Based on these loads determined through machine learning, the frequency offset lookup information can be updated (this can be called a semi-static post-event update).

[0101] In some embodiments, during the scanning phase, for a specific load, the transmit controller (e.g., a direct digital frequency synthesizer therein) generates output power based on a second updated frequency offset lookup information.

[0102] Therefore, for a specific load, the updated frequency offset lookup information can be used to eliminate or reduce the impact of load differences on the bandwidth of the transmitter, thereby further improving the performance of the transmitter and enhancing the quality of magnetic resonance images.

[0103] In some embodiments, it can be determined whether a specific load is the same as or similar to a predetermined load or a load determined by machine learning; if they are the same or similar (e.g., the difference is less than or equal to a preset threshold, or the difference is within a preset range), during the scanning phase, for the specific load, the transmit controller (e.g., the direct digital frequency synthesizer therein) generates output power based on the second updated frequency offset lookup information.

[0104] Therefore, for a specific load, the updated frequency offset lookup information corresponding to a typical load that is the same or similar to that specific load can be used to eliminate or reduce the impact of load differences on the bandwidth of the transmitting device, thereby further improving the performance of the transmitting device and enhancing the quality of the magnetic resonance images. In this case, the step of updating the frequency offset lookup information for each specific load in the pre-scanning stage can be skipped, improving scanning efficiency while ensuring scanning performance.

[0105] In some embodiments, it can be determined whether a specific load is the same as or similar to a pre-determined load or a load determined by machine learning; if they are not the same or similar (e.g., the difference is greater than a preset threshold, or the difference is outside a preset range),

[0106] During the pre-scanning phase, for a specific load, multiple training pulse signals modulated at different frequencies across the full bandwidth are generated, and the frequency offset lookup information is updated for the first time based on the multiple training pulse signals; and

[0107] During the scanning phase, for the specific load, the transmit controller (e.g., the direct digital frequency synthesizer therein) generates output power based on the first updated frequency offset lookup information.

[0108] Therefore, when there are no identical or similar reserved loads for a specific load, updating the frequency offset lookup information for that specific load can eliminate or reduce the impact of load differences on the bandwidth of the transmitting device, thereby further improving the performance of the transmitting device and enhancing the quality of the magnetic resonance images. In this case, updating the frequency offset lookup information for atypical loads during the pre-scanning stage can further improve scanning performance.

[0109] The above embodiments are merely illustrative examples of embodiments of this application, but this application is not limited thereto, and appropriate modifications can be made based on the above embodiments. For example, the above embodiments can be used alone, or one or more of the above embodiments can be combined.

[0110] As can be seen from the above embodiments, frequency offset lookup information for bandwidth compensation of the entire transmitting device is generated based on the bandwidth data of the transmit controller, RF amplifier, and signal processor. Therefore, this frequency offset lookup information can not only be used for digital predistortion processing of the power amplifier, but also improve the bandwidth performance of the entire transmitting device and enhance the quality of magnetic resonance images.

[0111] Furthermore, updating the frequency offset lookup information dynamically or semi-statically can eliminate or reduce the impact of load differences on the bandwidth of the transmitting device, thereby further improving the performance of the transmitting device and enhancing the quality of magnetic resonance images.

[0112] Second aspect of the embodiments

[0113] This application provides a transmitting device for a magnetic resonance imaging system. The working process of the transmitting device has been described in the first aspect of the embodiment, and the contents that are the same as those in the first aspect of the embodiment will not be repeated.

[0114] Figure 6 This is a schematic diagram of the transmitting device of a magnetic resonance imaging system according to an embodiment of this application. Figure 6 As shown, the transmitting device 600 of the magnetic resonance imaging system includes:

[0115] Transmitter controller 601, which is used to generate and output pulse signals;

[0116] Radio frequency amplifier 602, which is used to amplify the pulse signal;

[0117] Signal processor 603 is used to transmit the signal amplified by the radio frequency amplifier to the transmitting coil of the magnetic resonance imaging system.

[0118] like Figure 6 As shown, the transmitting device 600 of the magnetic resonance imaging system also includes:

[0119] The bandwidth compensation unit 604 generates frequency offset lookup information for bandwidth compensation of the entire transmitting device based on the bandwidth data of the transmit controller 601, the radio frequency amplifier 602 and the signal processor 603; the frequency offset lookup information is used to control the transmit controller 601 to generate output power.

[0120] Figure 6 The example shown includes a direct digital frequency synthesizer (DDS), a digital-to-analog converter (DAC), an RF front-end circuit, a feedback module, etc., but this application is not limited thereto. For specific structures of the transmitter controller 601, the RF amplifier 602, and the signal processor 603, please refer to related technologies.

[0121] In some embodiments, the bandwidth compensation unit 604 may be integrated into the transmit controller 601, for example, as a module of the transmit controller 601. Figure 3 As shown; the bandwidth compensation unit 604 can also be set separately from the transmit controller 601, for example Figure 6 As shown. The embodiments in this application are not limited thereto.

[0122] In some embodiments, the bandwidth data of the transmitter controller 601, the radio frequency amplifier 602, and the signal processor 603 are pre-generated according to a standard load, and the bandwidth data of the transmitter controller 601, the radio frequency amplifier 602, and the signal processor 603 are pre-stored in their respective memories.

[0123] In some embodiments, when the transmit controller 601, the radio frequency amplifier 602, and the signal processor 603 are integrated and initialized, the bandwidth compensation unit 604 obtains the bandwidth data of the transmit controller 601, the radio frequency amplifier 602, and the signal processor 603 from their respective memories.

[0124] In some embodiments, during the pre-scanning phase, for a specific load, the transmit controller 601 generates multiple training pulse signals modulated at different frequencies across the full bandwidth, and the bandwidth compensation unit 604 also performs a first update on the frequency offset lookup information based on the multiple training pulse signals.

[0125] During the scanning phase, for a specific load, the transmit controller 601 generates output power based on the first updated frequency offset lookup information.

[0126] In some embodiments, the bandwidth compensation unit 604 further updates the frequency offset lookup information based on a predetermined load or a load determined by machine learning.

[0127] During the scanning phase, for a specific load, the transmit controller 601 generates output power based on the second updated frequency offset lookup information.

[0128] In some embodiments, the transmit controller 601 further determines whether a particular load is the same as or similar to a predetermined load or a load determined by machine learning;

[0129] Under the same or similar circumstances, during the scanning phase for a specific load, the transmit controller 601 generates output power based on the second updated frequency offset lookup information;

[0130] In cases where they are not identical or similar, the transmit controller 601 generates multiple training pulse signals modulated at different frequencies across the full bandwidth for the specific load during the pre-scan phase, and the bandwidth compensation unit 604 also performs a first update on the frequency offset lookup information based on the multiple training pulse signals; and during the scan phase, for the specific load, the transmit controller 601 generates output power based on the first updated frequency offset lookup information.

[0131] For the sake of simplicity, Figure 6 The diagram only exemplifies the connection relationships or signal flow between various components or modules; however, those skilled in the art should understand that various related technologies, such as bus connections, can be employed. The aforementioned components or modules can be implemented using hardware facilities such as processors and memory; this application does not limit the scope of the embodiments.

[0132] The above embodiments are merely illustrative examples of embodiments of this application, but this application is not limited thereto, and appropriate modifications can be made based on the above embodiments. For example, the above embodiments can be used alone, or one or more of the above embodiments can be combined.

[0133] As can be seen from the above embodiments, frequency offset lookup information for bandwidth compensation of the entire transmitting device is generated based on the bandwidth data of the transmit controller, RF amplifier, and signal processor. Therefore, this frequency offset lookup information can not only be used for digital predistortion processing of the power amplifier, but also improve the bandwidth performance of the entire transmitting device and enhance the quality of magnetic resonance images.

[0134] Furthermore, updating the frequency offset lookup information dynamically or semi-statically can eliminate or reduce the impact of load differences on the bandwidth of the transmitting device, thereby further improving the performance of the transmitting device and enhancing the quality of magnetic resonance images.

[0135] Third aspect of the embodiments

[0136] This application also provides a magnetic resonance imaging system.

[0137] Figure 7 This is a schematic diagram of a magnetic resonance imaging system according to an embodiment of this application, as shown below. Figure 7 As shown, the magnetic resonance imaging system 700 includes: a transmitting coil 701 and a transmitting device 600 in the second aspect embodiment, which can be used to set scanning parameters before the MRI system performs a pre-scan or formal scan. The contents that are the same as those in the first and second aspect embodiments will not be repeated.

[0138] In some embodiments, the magnetic resonance imaging system may further include a main magnet assembly 702, a gradient coil assembly 703, a gradient coil driver 704, a receiving device 705, a controller 506, a scanning bed 707, an image processing unit 708, etc. Specific implementations can be found in related technologies, and the embodiments in this application are not intended to limit the scope of the invention.

[0139] In some embodiments, the main magnet assembly 702 typically includes, for example, a superconducting magnet with a main magnet coil disposed circumferentially along the superconducting magnet. The superconducting magnet is mounted within an annular vacuum container and defines a cylindrical imaging space surrounding the object to be scanned. A constant static magnetic field, such as a static magnetic field B0, is generated along the Z-direction of this imaging space. The MRI system uses the generated static magnetic field B0 to transmit a magnetic flux density pulse signal to the object to be scanned placed in the imaging space, thereby ordering the precession of protons within the object and generating a longitudinal magnetization vector.

[0140] In some embodiments, the transmitting coil 701 is typically arranged along the inner ring of the main magnet and is used to respond to an RF excitation pulse emitted from the transmitting device 600 to emit a radio frequency field B1 orthogonal to the static magnetic field B0 towards the object to be scanned, thereby exciting the atomic nuclei within the object and transforming the longitudinal magnetization vector into a transverse magnetization vector. For example, the controller 706 may instruct the transmitting controller 601 to generate a scanning sequence and generate an RF pulse signal, which is amplified by the RF amplifier 602 and then transmitted to the RF transmitting coil 701 by the signal processor 603.

[0141] In some embodiments, after the radio frequency excitation pulse ends, a free induction attenuation signal, i.e., a magnetic resonance signal that can be acquired, is generated as the transverse magnetization vector of the object to be scanned gradually returns to zero.

[0142] In some embodiments, the RF transmitting coil 701 can be switched between a transmitting mode and a receiving mode by a transmit / receive mode switch in the signal processor 603. In the receiving mode, the RF transmitting coil 701 can be used to receive magnetic resonance signals from the object to be scanned, which can also be acquired via an RF receiving coil 709 (optionally) located close to the object to be scanned.

[0143] In some embodiments, the controller 706 provides a gradient waveform to a gradient coil driver 704, which includes GX, GY, and GZ amplifiers, etc. Each GX, GY, and GZ gradient amplifier excites a corresponding gradient coil in the gradient coil assembly 703 to generate a magnetic field gradient for spatial encoding of MR signals during MRI scanning.

[0144] In some embodiments, the receiving device 705 is used to receive magnetic resonance signals acquired by the receiving coil 709 or the transmitting coil 701 in receiving mode. The receiving device 705 may include an RF preamplifier, a phase detector, and an analog-to-digital conversion module, etc., as detailed in related technologies. The RF preamplifier amplifies the received magnetic resonance signal, the phase detector performs phase detection on the amplified magnetic resonance signal, and the analog-to-digital conversion module converts the phase-detected magnetic resonance signal from an analog signal to a digital signal before sending it to the image processing unit 708.

[0145] In some embodiments, the image processing unit 708 can perform preprocessing, reconstruction, and other operations on the received digitized magnetic resonance signals to obtain the desired image or image data. The image processing unit 708 may include a processor and a storage medium on which a predetermined data processing program to be executed by the processor is recorded. The image processing unit 708 may be connected to a controller 706 and perform data processing based on control signals received from the controller 706. Optionally, the image processing unit 708 may be a separate device connected to the MRI system, or its functions may be integrated into the controller 706; this embodiment is not intended to limit the scope of the invention.

[0146] In some embodiments, the controller 706 may include a processor and a storage medium for storing a program that can be executed by the processor. When the computer executes the program, it can cause the components of the MRI system to perform corresponding operations to realize the scanning process of the object to be scanned. The scanning process may include a pre-scan and a formal scan after the pre-scan.

[0147] For example, the controller 706 can control the MRI system to perform a pre-scan according to a predetermined pulse sequence. This may involve, but is not limited to, controlling the amplitude, power, flip angle, and frequency of the RF pulse signal emitted by the transmitter 600, and controlling, but is not limited to, the power of the drive signal emitted by the gradient coil driver 704 and the density of the magnetic resonance signal acquired by the receiver 705.

[0148] Although the embodiments of the second aspect describe that the bandwidth compensation unit 604 can be a separate module component, or the bandwidth compensation unit 604 can be placed in the transmission controller 601, or the function of the bandwidth compensation unit 604 can be integrated into the transmission controller 601, the embodiments of this application are not intended to limit this. For example, the function of the bandwidth compensation unit 604 can be integrated into the processor of the transmission controller 601; however, it is understood that the function of the bandwidth compensation unit 604 can also be implemented by the controller 706.

[0149] In some embodiments, the MRI system may also include user input devices (not shown), such as a keyboard and mouse, through which the operator can input operation signals to the controller 706. For example, the user can send pre-set scan parameters to the controller 706 through the input devices.

[0150] In some embodiments, the MRI system may further include a display unit 710. The display unit 710 may be connected to an input device to display an operating interface, or it may be connected to an image processing unit 708 to display images. Additionally, the storage media in the controller 706 and the image processing unit 708, as well as the memory, may include, for example, ROM, floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, or non-volatile memory card, etc., and the embodiments of this application are not intended to limit this. Furthermore, the magnetic resonance imaging system 700 may also include... Figure 7 Components not shown in the document, such as physiological data acquisition controllers and scanning object positioning devices, can be found in relevant technologies and will not be listed here.

[0151] This application also provides a computer-readable program, wherein when the program is executed in a transmitting device or MRI system, the program causes the computer to perform the transmitting method as described in the first aspect of the embodiment in the transmitting device or MRI system.

[0152] This application also provides a storage medium storing a computer-readable program, wherein the computer-readable program causes a computer to perform the transmission method as described in the first aspect embodiment in a transmission device or MRI system.

[0153] The apparatus and methods described above in this application can be implemented in hardware or in combination with software. This application relates to a computer-readable program that, when executed by a logic component, enables the logic component to implement the apparatus or components described above, or to implement the various methods or steps described above. This application also relates to storage media for storing the above programs, such as hard disks, magnetic disks, optical disks, DVDs, flash memory, etc.

[0154] The methods / apparatus described in conjunction with the embodiments of this application can be directly embodied in hardware, software modules executed by a processor, or a combination of both. For example, one or more and / or combinations of one or more functional block diagrams shown in the figures can correspond to various software modules in a computer program flow, or to various hardware modules. These software modules can correspond to the various steps shown in the figures, respectively. These hardware modules can be implemented, for example, using a field-programmable gate array (FPGA) to embed these software modules.

[0155] The software module can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. A storage medium can be coupled to the processor, enabling the processor to read information from and write information to the storage medium; or the storage medium can be an integral part of the processor. The processor and storage medium can reside in an ASIC. The software module can be stored in the memory of a mobile terminal or in a memory card that can be inserted into the mobile terminal. For example, if the device (such as a mobile terminal) uses a high-capacity MEGA-SIM card or a high-capacity flash memory device, the software module can be stored in the MEGA-SIM card or the high-capacity flash memory device.

[0156] One or more and / or one or more combinations of functional blocks described in the accompanying drawings can be implemented as a general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, or any suitable combination thereof for performing the functions described herein. One or more and / or one or more combinations of functional blocks described in the accompanying drawings can also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in communication with a DSP, or any other such configuration.

[0157] The present application has been described above with reference to specific embodiments. However, those skilled in the art should understand that these descriptions are exemplary and not intended to limit the scope of protection of the present application. Those skilled in the art can make various modifications and variations to the present application based on the principles thereof, and these modifications and variations are also within the scope of the present application.

Claims

1. A method for transmitting signals in a magnetic resonance imaging system, the method comprising: The pulse signal is generated and output by the transmit controller; The pulse signal is amplified by a radio frequency amplifier; The signal processor transmits the amplified signal from the radio frequency amplifier to the transmitting coil of the magnetic resonance imaging system. The method is characterized in that it further includes: The transmit controller is controlled based on frequency offset lookup information to generate output power; wherein, the frequency offset lookup information is information pre-generated based on the bandwidth data of the transmit controller, the RF amplifier and the signal processor for bandwidth compensation of the entire transmit device.

2. The method according to claim 1, characterized in that, The bandwidth data of the transmitter controller, the radio frequency amplifier, and the signal processor are pre-generated according to a standard load, and the bandwidth data of the transmitter controller, the radio frequency amplifier, and the signal processor are pre-stored in their respective memories.

3. The method according to claim 2, characterized in that, The method further includes: When the transmit controller, the RF amplifier, and the signal processor are integrated and initialized, the bandwidth data of the transmit controller, the RF amplifier, and the signal processor are obtained from their respective memories.

4. The method according to claim 1, characterized in that, The method further includes: During the pre-scan phase, multiple training pulse signals modulated at different frequencies across the full bandwidth are generated for a specific load. The frequency offset lookup information is updated for the first time based on the plurality of training pulse signals.

5. The method according to claim 4, characterized in that, The method further includes: During the scanning phase, for the specific load, the transmit controller generates output power based on the first updated frequency offset lookup information.

6. The method according to claim 1, characterized in that, The method further includes: The frequency offset lookup information is updated a second time based on a predetermined load or a load determined through machine learning.

7. The method according to claim 6, characterized in that, The method further includes: During the scanning phase, for a specific load, the transmit controller generates output power based on the second updated frequency offset lookup information.

8. The method according to claim 6, characterized in that, The method further includes: Determine whether a specific load is the same as or similar to a pre-determined load or a load determined by machine learning; Under the same or similar circumstances, during the scanning phase for the specific load, the transmit controller generates output power based on the second updated frequency offset lookup information.

9. The method according to claim 8, characterized in that, In cases where they are not the same or dissimilar During the pre-scanning phase, for the specific load, multiple training pulse signals modulated at different frequencies across the full bandwidth are generated, and the frequency offset lookup information is updated for the first time based on the multiple training pulse signals. as well as During the scanning phase, for the specific load, the transmit controller generates output power based on the first updated frequency offset lookup information.

10. A transmitting device for a magnetic resonance imaging system, the device comprising: A transmitter controller, used to generate and output pulse signals; A radio frequency amplifier, used to amplify the pulse signal; A signal processor, which transmits the signal amplified by the radio frequency amplifier to the transmitting coil of the magnetic resonance imaging system; The device is characterized in that it further includes: A bandwidth compensation unit controls the transmit controller to generate output power based on frequency offset lookup information; wherein the frequency offset lookup information is information pre-generated based on bandwidth data of the transmit controller, the RF amplifier, and the signal processor for bandwidth compensation of the entire transmitting device.

11. The apparatus according to claim 10, characterized in that, The bandwidth data of the transmitter controller, the radio frequency amplifier, and the signal processor are pre-generated according to a standard load, and the bandwidth data of the transmitter controller, the radio frequency amplifier, and the signal processor are pre-stored in their respective memories.

12. The apparatus according to claim 11, characterized in that, When the transmit controller, the RF amplifier, and the signal processor are integrated and initialized, the bandwidth compensation unit obtains the bandwidth data of the transmit controller, the RF amplifier, and the signal processor from their respective memories.

13. The apparatus according to claim 10, characterized in that, During the pre-scan phase, for a specific load, the transmit controller generates multiple training pulse signals modulated at different frequencies across the full bandwidth, and the bandwidth compensation unit also performs a first update on the frequency offset lookup information based on the multiple training pulse signals.

14. The apparatus according to claim 13, characterized in that, During the scanning phase, for the specific load, the transmit controller generates output power based on the first updated frequency offset lookup information.

15. The apparatus according to claim 10, characterized in that, The bandwidth compensation unit further updates the frequency offset lookup information a second time based on a predetermined load or a load determined through machine learning.

16. The apparatus according to claim 15, characterized in that, During the scanning phase, for a specific load, the transmit controller generates output power based on the second updated frequency offset lookup information.

17. The apparatus according to claim 15, characterized in that, The launch controller also determines whether a specific load is the same as or similar to a pre-determined load or a load determined by machine learning; Under the same or similar circumstances, during the scanning phase for the specific load, the transmit controller generates output power based on the second updated frequency offset lookup information.

18. The apparatus according to claim 17, characterized in that, In cases where they are not the same or similar, the transmit controller generates multiple training pulse signals modulated at different frequencies across the full bandwidth for the specific load during the pre-scan phase, and the bandwidth compensation unit also performs a first update on the frequency offset lookup information based on the multiple training pulse signals. During the scanning phase, for the specific load, the transmit controller generates output power based on the first updated frequency offset lookup information.

19. A magnetic resonance imaging system, the system comprising: Transmitting coil; as well as The launching device according to any one of claims 10 to 18.

20. A storage medium storing a computer-readable program, characterized in that, The computer-readable program causes a computer to perform the launching method described in any one of claims 1 to 9 in the device.

Images