Magnetic resonance image generation method and apparatus, computer device, and storage medium

Abstract

The application relates to a magnetic resonance image generation method and device, computer equipment and a storage medium. The method comprises the following steps: in a target cardiac cycle, a preparation module is applied in response to receiving an electrocardio trigger signal to flip a first initial longitudinal magnetization vector corresponding to a detection object into a first transverse magnetization vector and to scatter into a first vector value; an inversion recovery pulse is applied in response to reaching a vector recovery time after the preparation module is applied; magnetic resonance data of the detection object is acquired by using a target imaging sequence in response to reaching an inversion recovery time after the inversion recovery pulse is applied; and the magnetic resonance data is reconstructed to obtain a target magnetic resonance image of the detection object. The method ensures that the longitudinal magnetization vector corresponding to the detection object is recovered from the first vector value to the signal strength of the vector recovery time before the inversion recovery pulse is applied at the interval vector recovery time, so that the longitudinal magnetization vectors corresponding to the detection object are all the same, and the quality of the magnetic resonance image is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of image processing, in particular to a magnetic resonance image generation method and device, computer equipment and storage medium. BACKGROUND

[0002] The magnetic resonance cardiac delayed enhancement imaging technology is generally to inject contrast agent for 10 minutes, and then use fast gradient echo imaging sequence under the conditions of electrocardiogram gating and breath holding, use non-selective inversion recovery pulse, selectively suppress normal myocardial signal, and highlight the enhanced infarct myocardial tissue.

[0003] The traditional magnetic resonance cardiac delayed enhancement imaging method includes: applying an inversion recovery pulse after a certain delay time of each electrocardio R wave, applying a fast imaging sequence when reaching the TI time after the application of the inversion recovery pulse, and acquiring magnetic resonance imaging data based on the longitudinal magnetization vector corresponding to the current heart, and then reconstructing the magnetic resonance image based on the magnetic resonance imaging data.

[0004] However, using the traditional technology, the longitudinal magnetization vector corresponding to the heart in the magnetic resonance imaging process may not be fully recovered, resulting in artifacts in imaging, so the quality of the magnetic resonance image is low. SUMMARY

[0005] Therefore, it is necessary to provide a magnetic resonance image generation method, device, computer equipment and storage medium capable of improving image quality in view of the above technical problems.

[0006] A magnetic resonance image generation method, the method comprising:

[0007] In a target cardiac cycle, a preparation module is applied in response to receiving an electrocardio trigger signal to flip the first initial longitudinal magnetization vector corresponding to the detection object into a first transverse magnetization vector, and to scatter into a first vector value;

[0008] A magnetization preparation pulse is applied to the detection object, and magnetic resonance data of the detection object is acquired after the magnetization preparation pulse is excited;

[0009] The magnetic resonance data is reconstructed to obtain a target magnetic resonance image of the detection object.

[0010] In one of the embodiments, the magnetization preparation pulse applied to the detection object comprises:

[0011] An inversion recovery pulse is applied in response to reaching the vector recovery time after the application of the preparation module;

[0012] A target scanning sequence is applied to the detection object in response to reaching the inversion recovery time after the application of the inversion recovery pulse.

[0013] In one of the embodiments, the applying the magnetization preparation pulse to the detection object comprises:

[0014] In response to reaching a set time after the preparation module is applied, a target scan sequence is applied to the detection object.

[0015] In one of the embodiments, the method further comprises:

[0016] In a reference cardiac cycle, in response to a preset waiting time after receiving an electrocardio trigger signal, a reference signal is acquired using a reference imaging sequence;

[0017] The reference signal is reconstructed to obtain a reference image;

[0018] According to the target magnetic resonance image and the reference image, a phase-sensitive real part image is obtained.

[0019] In one of the embodiments, according to the target magnetic resonance image and the reference image, a phase-sensitive real part image is obtained, comprising:

[0020] The target magnetic resonance image and the reference image are registered;

[0021] The registered target magnetic resonance image and the reference image are phase-sensitive inversion recovery reconstructed to obtain a phase-sensitive real part image.

[0022] In one of the embodiments, in the reference cardiac cycle, the detection object is a heart, in the reference cardiac cycle, in response to a preset waiting time after receiving an electrocardio trigger signal, a reference signal is acquired using a reference imaging sequence, comprising:

[0023] In a reference cardiac cycle, in response to receiving an electrocardio trigger signal, a preparation module is applied to flip a second initial longitudinal magnetization vector corresponding to the heart into a second transverse magnetization vector, and to dephase into a second vector value;

[0024] In response to reaching a vector recovery time after the preparation module is applied, a reference signal is acquired using the reference imaging sequence.

[0025] In one of the embodiments, the resolution of the target magnetic resonance image is greater than the resolution of the reference image.

[0026] In one of the embodiments, the target imaging sequence comprises a target flip angle radio frequency pulse, the reference imaging sequence comprises a reference flip angle radio frequency pulse, and the reference flip angle is less than or equal to the target flip angle.

[0027] In one of the embodiments, the first K-space data corresponding to the target magnetic resonance image is filled by magnetic resonance data in a plurality of adjacent target cardiac cycles.

[0028] A magnetic resonance image generation apparatus, the apparatus comprising:

[0029] A preparation module application module is configured to apply a preparation module to flip a first initial longitudinal magnetization vector corresponding to the detection object to a first transverse magnetization vector and to scatter a first vector value in a target cardiac cycle in response to receiving an electrocardio trigger signal.

[0030] A magnetic resonance data acquisition module is configured to apply a magnetization preparation pulse to the detection object and acquire magnetic resonance data of the detection object after the magnetization preparation pulse is excited.

[0031] A magnetic resonance image generation module is configured to reconstruct the magnetic resonance data to obtain a target magnetic resonance image of the detection object.

[0032] A computer device comprising a memory and a processor, the memory stores a computer program, and the processor implements the following steps when executing the computer program:

[0033] A preparation module application module is configured to apply a preparation module to flip a first initial longitudinal magnetization vector corresponding to the detection object to a first transverse magnetization vector and to scatter a first vector value in a target cardiac cycle in response to receiving an electrocardio trigger signal.

[0034] A magnetic resonance data acquisition module is configured to apply a magnetization preparation pulse to the detection object and acquire magnetic resonance data of the detection object after the magnetization preparation pulse is excited.

[0035] A magnetic resonance image generation module is configured to reconstruct the magnetic resonance data to obtain a target magnetic resonance image of the detection object.

[0036] A computer readable storage medium having a computer program stored thereon, the computer program being executed by a processor to implement the following steps:

[0037] A preparation module application module is configured to apply a preparation module to flip a first initial longitudinal magnetization vector corresponding to the detection object to a first transverse magnetization vector and to scatter a first vector value in a target cardiac cycle in response to receiving an electrocardio trigger signal.

[0038] A magnetic resonance data acquisition module is configured to apply a magnetization preparation pulse to the detection object and acquire magnetic resonance data of the detection object after the magnetization preparation pulse is excited.

[0039] A magnetic resonance image generation module is configured to reconstruct the magnetic resonance data to obtain a target magnetic resonance image of the detection object.

[0040] The magnetic resonance image generation method, device, computer device and storage medium described above, by applying the preparation module after receiving the ECG trigger signal in the target cardiac cycle, the first initial longitudinal magnetization vector of the detection object is flipped to the first transverse magnetization vector, and the scattered phase is the first vector value, for example, zero. Therefore, before the inversion recovery pulse is applied within the interval vector recovery time, the longitudinal magnetization vector of the detection object is recovered from the first vector value to the signal intensity of the vector recovery time, so that the longitudinal magnetization vectors corresponding to different cardiac cycles of the detection object are the same, avoiding the generation of artifacts in the magnetic resonance image caused by the inconsistency of the longitudinal magnetization vectors before multiple inversion recovery pulses are applied in multiple target cardiac cycles, and facilitating the improvement of the quality of the magnetic resonance image. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 A flowchart of a magnetic resonance image generation method in an embodiment;

[0042] Figure 2 A pulse application schematic diagram of a magnetic resonance image generation method in an embodiment;

[0043] Figure 2A A preparation module schematic diagram of a magnetic resonance image generation method in an embodiment;

[0044] Figure 3 A pulse application schematic diagram of a magnetic resonance image generation method in another embodiment;

[0045] Figure 4 A pulse application schematic diagram of a magnetic resonance image generation method in another embodiment;

[0046] Figure 5 A pulse application schematic diagram of a target magnetic resonance image generation in an embodiment;

[0047] Figure 6 A pulse application schematic diagram of a target magnetic resonance image generation in another embodiment;

[0048] Figure 7 A structure block diagram of a magnetic resonance image generation device in an embodiment;

[0049] Figure 8 An internal structure diagram of a computer device in an embodiment. DETAILED DESCRIPTION

[0050] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0051] The application provides a magnetic resonance image generation method, which comprises the following steps:

[0052] Optionally, the preparation module comprises a radio frequency saturation pulse and a dispersion gradient pulse, wherein the radio frequency saturation pulse is used to realize the flip of the longitudinal magnetization vector corresponding to the detection object into a transverse magnetization vector, and the dispersion gradient pulse is used to realize the dispersion of the transverse magnetization vector.

[0053] Optionally, the magnetization preparation pulse applied to the detection object can be a T2 preparation pulse or an inversion recovery pulse. For example, in response to the vector recovery time after the application of the preparation module, the inversion recovery pulse is applied; and in response to the inversion recovery time after the application of the inversion recovery pulse, the target scan sequence is applied to the detection object to acquire the magnetic resonance data of the detection object. For another example, in response to a set time after the application of the preparation module, the T2 preparation pulse is applied to the detection object; and the target scan sequence is applied to the detection object to acquire the magnetic resonance data of the detection object.

[0054] In one embodiment, as shown in Figure 1 The application provides a magnetic resonance image generation method, which comprises the following steps:

[0055] In step S102, in a target cardiac cycle, a preparation module is applied in response to the reception of an electrocardio trigger signal, so as to flip a first initial longitudinal magnetization vector corresponding to a detection object into a first transverse magnetization vector and disperse the first vector value. The detection object can be a heart, and the physiological motion cycle / cardiac cycle of the heart is monitored by using an external electrocardiogram (ECG) device during the detection process.

[0056] The cardiac cycle refers to one mechanical activity cycle composed of one contraction and one diastole of the heart. The electrocardio trigger signal can be an electrocardio wave signal. The electrocardio wave can be an R wave, a P wave, a T wave and the like. The longitudinal magnetization vector refers to the magnetic moment vector sum in the direction of the static magnetic field. The transverse magnetization vector refers to the magnetic moment vector sum in the plane perpendicular to the direction of the static magnetic field.

[0057] Specifically, as shown in Figure 2As shown in the magnetic resonance cardiac delayed enhancement imaging, after the terminal receives the ECG trigger signal in the target cardiac cycle, the terminal applies a preparation module (SR in the figure after the R wave of the ECG trigger signal) after waiting for a trigger delay time (TD) greater than or equal to 0 ms. The function of the preparation module is to flip the first initial longitudinal magnetization vector of the heart into a first transverse magnetization vector, and to dephase the first transverse magnetization vector into a first vector value. Optionally, the first vector value can be 0, 1 or other numerical values.

[0058] As Figure 2A The preparation module timing diagram of an embodiment of the present application. The SR is composed of a plurality of saturation pulses and dephasing gradients. In this embodiment, the SR specifically includes a plurality of 90° saturation pulses (the selective gradient in the slice direction is not shown), and a dephasing gradient can be applied in the phase encoding direction (Gpe), the frequency encoding direction (Gro) or the slice selection direction (Gss) after each 90° saturation pulse. Each 90° frequency selective pulse has the same half-width, and the interval between two adjacent 90° frequency selective pulses is the same. It can be understood that the type, number, half-width of the pre-preparation module included in the SR and the interval between adjacent pulses can be set according to the cardiac tissue of different detection objects. In the embodiment of the present application, by setting the SR as a plurality of pre-preparation modules, it can be applied to the case that the main magnetic field of the magnetic resonance system is non-uniform and the radio frequency transmission field is non-uniform, that is, it is not sensitive to the non-uniformity of the main magnetic field and the radio frequency field, and especially for the super high field (5 tesla and above) environment, the dephasing effect after the preparation module is applied in the target cardiac cycle can be improved.

[0059] Step S104, in response to reaching the vector recovery time after the preparation module is applied, an inversion recovery pulse is applied.

[0060] Specifically, the terminal applies an inversion recovery pulse (IR in the figure) to invert the longitudinal magnetization vector recovered for T time to a negative direction after the preparation module is applied for an interval of the vector recovery time T.

[0061] Step S106, in response to reaching the inversion recovery time after the inversion recovery pulse is applied, the magnetic resonance data of the detection object is acquired by using the target imaging sequence.

[0062] Specifically, the target imaging sequence (IMG in the figure) is excited to collect the magnetic resonance data at the current time after the inversion recovery pulse is applied for an interval of the inversion recovery time T1. In this embodiment, the target imaging sequence is excited after the TT (trigger time) time of each cardiac cycle. According to the different inversion recovery time T1, the TT corresponding to different cardiac cycles is also different.

[0063] Step S108, reconstruct the magnetic resonance data to obtain the target magnetic resonance image of the detection object.

[0064] Specifically, the terminal reconstructs the magnetic resonance data corresponding to the target imaging sequence to obtain the target magnetic resonance image. Optionally, the terminal performs imaging according to the magnetic resonance data corresponding to the target fast imaging sequence (IMG) to obtain the target magnetic resonance image. Optionally, the target fast imaging sequence can be a gradient recalled echo (GRE) sequence, or a balanced steady state free precession (bSSFP) sequence based on GRE.

[0065] Optionally, the terminal fills the magnetic resonance data corresponding to the target imaging sequence in K-space, and then performs Fourier reconstruction on the filled data in K-space to obtain the target magnetic resonance image. It can be understood that the terminal acquires a part of K-space data of K-space of the delay enhancement data in each target cardiac cycle, wherein the magnetic resonance data acquired after the latter IR and the former IR are filled in different phase encoding positions of K-space, until the entire K-space is filled completely, and the magnetic resonance data in the entire K-space is reconstructed to obtain the target magnetic resonance image.

[0066] In the above magnetic resonance image generation method, after receiving the electrocardiogram trigger signal in the target cardiac cycle, the preparation module is applied to flip the first initial longitudinal magnetization vector corresponding to the detection object into a first transverse magnetization vector, and the scattered phase is a first vector value, for example, zero. In this way, it can be ensured that the longitudinal magnetization vector corresponding to the detection object is recovered from the first vector value to the signal intensity of the vector recovery time before the inversion recovery pulse is applied at the interval vector recovery time, so that the longitudinal magnetization vectors corresponding to different cardiac cycles of the detection object are the same, avoiding the generation of artifacts in the magnetic resonance image due to the inconsistency of the longitudinal magnetization vectors before multiple inversion recovery pulses are applied in multiple target cardiac cycles, and being beneficial to improving the quality of the magnetic resonance image.

[0067] In one embodiment, the method further comprises the following steps:

[0068] Step S112, in the reference cardiac cycle, a reference signal is acquired using a reference imaging sequence in response to a preset waiting time after receiving the electrocardiogram trigger signal;

[0069] Step S114, reconstructing the reference signal to obtain a reference image;

[0070] In step S116, a phase sensitive real part image is obtained according to the target magnetic resonance image and the reference image. Optionally, the target magnetic resonance image and the reference image are subjected to a registration operation; and the phase sensitive real part image is obtained by performing phase sensitive inversion recovery reconstruction on the registered target magnetic resonance image and the reference image.

[0071] The reference cardiac cycle can be a next cardiac cycle adjacent to the target cardiac cycle.

[0072] The phase sensitive inversion recovery (PSIR) is a pulse sequence using two inversion recovery pre-pulses. In a first step, different inversion time (TI) magnetic resonance images are quickly acquired by using a segmented or single shot pulse to determine different TI values, so as to maximize the delayed enhancement tissue contrast. In a second step, a segmented inversion recovery pre-pulse is used to acquire a corresponding TI weighted image at the selected TI, so as to evaluate the characteristics of the myocardial activity.

[0073] Specifically, in the reference cardiac cycle, no inversion recovery pulse is applied. After receiving the electrocardio trigger signal, the terminal acquires a reference signal by using a reference imaging sequence (Ref in the figure) after a preset waiting time. Then, the terminal reconstructs the reference signal to obtain a reference image. The reference imaging sequence is a reference imaging sequence in the phase sensitive inversion recovery. Finally, the terminal processes the target magnetic resonance image and the reference image by using a phase sensitive inversion recovery algorithm to obtain a phase sensitive real part image.

[0074] Optionally, the terminal fills the reference signal corresponding to the reference imaging sequence in K-space, and then performs Fourier reconstruction on the reference signal corresponding to the reference imaging sequence in K-space to obtain the reference image. It can be understood that the terminal acquires part of K-space data of K-space of the delayed enhancement data in each reference cardiac cycle until the entire K-space is filled, and reconstructs the data in the entire K-space to obtain the reference image.

[0075] In this embodiment, the acquisition of the phase sensitive real part image is realized by acquiring the reference image and then performing the phase sensitive inversion recovery processing.

[0076] In one embodiment, a possible implementation of the above step S112 "in the reference cardiac cycle, a reference signal is acquired by using a reference imaging sequence after a preset waiting time from receiving an electrocardio trigger signal" is involved. On the basis of the above embodiment, step S112 can be implemented by the following steps:

[0077] Step S1122, in the reference cardiac cycle, a preparation module is applied in response to receiving the electrocardiogram trigger signal to flip the second initial longitudinal magnetization vector corresponding to the heart into a second transverse magnetization vector, and to dephasing the second vector value;

[0078] Step S1124, in response to reaching the vector recovery time after the preparation module is applied, a reference signal is acquired using the reference imaging sequence.

[0079] The preset waiting time includes the preparation module application time and the vector recovery time.

[0080] Specifically, as shown in Figure 3 In the reference cardiac cycle, after the terminal receives the electrocardiogram trigger signal, the terminal applies the preparation module (SR in the figure) after waiting for a trigger delay time TD greater than or equal to 0 ms. The function of the preparation module is to flip the second initial longitudinal magnetization vector corresponding to the heart into a second transverse magnetization vector, and to dephase the second transverse magnetization vector to a second vector value. Optionally, the second vector value can be 0, 1 or other numerical values. Then, after a vector recovery time interval after the preparation module is applied, a reference signal is acquired using the reference imaging sequence.

[0081] In this embodiment, by applying the preparation module after receiving the electrocardiogram trigger signal in the reference cardiac cycle, the second initial longitudinal magnetization vector corresponding to the heart is flipped into a second transverse magnetization vector, and is dephased to a second vector value such as zero. This can ensure that before the reference image is imaged, the longitudinal magnetization vector corresponding to the heart is recovered from the second vector value to the signal strength of the vector recovery time, so that the longitudinal magnetization vector corresponding to the heart is the same, avoiding the generation of artifacts in the reference image due to the inconsistency of the longitudinal magnetization vector before the reference image is imaged in multiple reference cardiac cycles, and facilitating the improvement of the quality of the reference image.

[0082] As shown in Figure 4 In one embodiment, the magnetic resonance data of the detection object can be uniformly collected in the first few target cardiac cycles to obtain a complete K-space data, and then the target magnetic resonance image is reconstructed. Similarly, in the last few reference cardiac cycles, the reference data is uniformly collected, and the reference image is reconstructed. In this embodiment, a complete K-space data is obtained by continuous collection, which can ensure the integrity and accuracy of the magnetic resonance data, and is conducive to improving the quality of the subsequently generated magnetic resonance image.

[0083] Optionally, in one embodiment, applying a magnetization preparation pulse to the target and acquiring the target's magnetic resonance data after the magnetization preparation pulse is excited includes: applying a T2 preparation pulse to the target in response to a set time after the preparation module is applied; and applying a target scan sequence to the target to acquire the target's magnetic resonance data. For example, after detecting an ECG trigger signal, a saturation pulse is used to flip the longitudinal magnetization vector to the transverse direction, then a dephasing gradient is used to dephasing the transverse magnetization vector to 0. After waiting for a certain time, a T2 preparation pulse is used, and then data acquisition is performed. This can eliminate the influence of initial Mz inconsistency caused by drastic changes in the cardiac cycle and reduce the scan time. This embodiment can be used for data acquisition before or after drug administration.

[0084] like Figure 5 As shown, during the first cardiac cycle, after detecting an ECG trigger signal, a preparation module SR, including a saturation pulse and a astigmatic gradient, is used to flip the longitudinal magnetization vector to the lateral direction, and then astigmatism is performed using the astigmatic gradient. Then, after waiting for a first time interval (the application interval TT between SR and IMG), an IMG sequence is executed for the first set of data acquisition. Two cardiac cycles later, during the second cardiac cycle, after detecting an ECG trigger signal, a preparation module SR, including a saturation pulse and an astigmatic gradient, is used to flip the longitudinal magnetization vector to the lateral direction, and then astigmatism is performed using the astigmatic gradient. Then, after waiting for a second time interval (the same application interval TT between SR and IMG), a T2 preparation pulse (T2 pre 1) is used, and an IMG sequence is executed for the second set of data acquisition. Two cardiac cycles later, during the third cardiac cycle, after detecting an ECG trigger signal, a preparation module SR, including a saturation pulse and an astigmatic gradient, is used to flip the longitudinal magnetization vector to the lateral direction, and then astigmatism is performed using the astigmatic gradient. Then, after waiting for a third time interval (the same application interval TT between SR and IMG), a T2 preparation pulse (T2 pre 1) is used. 2) Perform the IMG sequence to acquire the third set of data; reconstruct the first, second, and third sets of data to obtain the T2Mapping image of the detected object. This application proposes a rapid cardiac T2Mapping (lateral relaxation time) imaging method. Based on the traditional T2Mapping imaging sequence, a saturation pulse is added, followed by a waiting period before T2Mapping imaging. This ensures that the initial longitudinal magnetization vector is consistent each time, eliminating the need to wait for the longitudinal magnetization vector to recover. Acquisition is performed for each cardiac cycle, significantly saving scan time, reducing the patient's breath-holding time, increasing scan efficiency, and overcoming the influence of drastic changes in the cardiac cycle.

[0085] To shorten the scan time, the acquisition can be performed per cardiac cycle, to increase the amount of data acquired, to provide accuracy of the T2 fitting, without changing the scan time, still using multiple T2 preparation times:

[0086] Please refer to Figure 6 In the first cardiac cycle, after detecting the ECG trigger signal, a preparation module SR including a saturation pulse and a spoiling gradient is used to flip the longitudinal magnetization vector to the transverse direction, and then a spoiling gradient is used for spoiling; then wait for a first time (the application interval TT of SR and IMG), execute the IMG sequence to perform first group data acquisition; adjacent to the first cardiac cycle, in the second cardiac cycle, after detecting the ECG trigger signal, a preparation module SR including a saturation pulse and a spoiling gradient is used to flip the longitudinal magnetization vector to the transverse direction, and then a spoiling gradient is used for spoiling; then wait for a second time (the application interval TT of SR and IMG), use T2 preparation pulse (T2 pre 1), execute the IMG sequence to perform second group data acquisition; adjacent to the second cardiac cycle, in the third cardiac cycle, after detecting the ECG trigger signal, a preparation module SR including a saturation pulse and a spoiling gradient is used to flip the longitudinal magnetization vector to the transverse direction, and then a spoiling gradient is used for spoiling; then wait for a third time (the application interval TT of SR and IMG), use T2 preparation pulse (T2 pre 2), execute the IMG sequence to perform third group data acquisition; reconstruct the first group data, the second group data and the third group data to obtain the T2 mapping image of the detection object.

[0087] In one embodiment, a possible implementation of the above-mentioned step S108 "reconstructing the magnetic resonance data to obtain the target magnetic resonance image of the detection object" is involved. Based on the above-mentioned embodiment, step S108 can be implemented by the following steps:

[0088] Step S1082, imaging according to the magnetic resonance data corresponding to the target imaging sequence at the target resolution associated with the target imaging sequence to obtain the target magnetic resonance image.

[0089] Further, a possible implementation of the above-mentioned step S114 "reconstructing the reference signal to obtain the reference image" is involved. Based on the above-mentioned embodiment, step S114 can be implemented by the following steps:

[0090] Step S1142, imaging according to the reference signal corresponding to the reference imaging sequence at the reference resolution associated with the reference imaging sequence to obtain the reference image.

[0091] Wherein, the reference resolution is less than the target resolution.

[0092] Specifically, the terminal performs imaging according to the magnetic resonance data corresponding to the target imaging sequence at a target resolution associated with the target imaging sequence, to generate a high-resolution target magnetic resonance image. The terminal performs imaging according to the reference signal corresponding to the reference imaging sequence at a reference resolution associated with the reference imaging sequence, to obtain a low-resolution reference image.

[0093] In this embodiment, the low-resolution reference image is acquired, which is advantageous for reducing the magnetic resonance image generation time.

[0094] In one embodiment, a possible implementation of the above-mentioned step S108 "reconstructing the magnetic resonance data to obtain a target magnetic resonance image of the detection object" is involved. On the basis of the above-mentioned embodiment, step S108 can be implemented by the following steps:

[0095] Step S108a, performing imaging according to the magnetic resonance data corresponding to the target imaging sequence at a target flip angle associated with the target imaging sequence, to obtain a target magnetic resonance image.

[0096] Further, a possible implementation of the above-mentioned step S112 "acquiring a reference signal using a reference imaging sequence" is involved. On the basis of the above-mentioned embodiment, step S112 can be implemented by the following steps:

[0097] Step S112a, setting parameters of the reference imaging sequence, wherein the flip angle of the radio frequency pulse in the reference imaging sequence is set to a reference flip angle.

[0098] Wherein, the flip angle of the radio frequency pulse in the target imaging sequence is set to a target flip angle. The reference flip angle is less than or equal to the target flip angle.

[0099] In this embodiment, the same reference flip angle as the target flip angle is used to acquire the reference image, which is advantageous for improving the signal-to-noise ratio of the reference image.

[0100] Optionally, before reconstructing the reference image and the target magnetic resonance image, the method may further include: acquiring the physiological motion curve of the object being detected; and filtering the magnetic resonance data corresponding to the target imaging sequence and the reference signal corresponding to the reference imaging sequence based on the physiological motion curve. In one embodiment, a set threshold is provided, retaining only the data acquired during cardiac phases with signal intensity within the set threshold range on the physiological motion curve. During reconstruction, the magnetic resonance data corresponding to the target imaging sequence and the reference signal corresponding to the reference imaging sequence acquired during cardiac phases exceeding the set threshold range are not used. Alternatively, for magnetic resonance data corresponding to the target imaging sequence acquired within the target cardiac cycle and where the cardiac phase exceeds the set threshold range, re-acquisition is performed. In this embodiment, it is applicable to objects with arrhythmia. When a cardiac cycle is detected to be too short or too long, the data acquired during that cardiac cycle is discarded and re-acquired, avoiding the impact on image quality due to unsatisfactory data acquisition in a single cycle. The above filtering process is performed in real time, avoiding the need for re-acquisition of the entire target imaging sequence due to arrhythmia in a single cardiac cycle, thus improving the efficiency of cardiac scanning.

[0101] It should be understood that, although Figure 1 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 1 At least some of the steps in the process may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but may be executed at different times. The execution order of these steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least some of the steps or stages in other steps.

[0102] In one embodiment, such as Figure 7 As shown, a magnetic resonance image generation device is provided, comprising: a preparation module, an application module 202, a magnetic resonance data acquisition module 204, and a magnetic resonance image generation module 206, wherein:

[0103] The preparation module application module 202 is used to apply the preparation module in response to receiving an electrocardiogram trigger signal during the target cardiac cycle, so as to flip the first initial longitudinal magnetization vector corresponding to the detection object into a first transverse magnetization vector and dephasing into a first vector value.

[0104] The magnetic resonance data acquisition module 204 is used to apply a magnetization preparation pulse to the object being detected and to acquire the magnetic resonance data of the object being detected after the magnetization preparation pulse is excited.

[0105] The magnetic resonance image generation module 206 is configured to reconstruct the magnetic resonance data to obtain the target magnetic resonance image of the detection object.

[0106] In the magnetic resonance image generation device, the preparation module is applied after the electrocardiogram trigger signal is received in the target cardiac cycle, so that the first initial longitudinal magnetization vector of the detection object is flipped to a first transverse magnetization vector, and the spin is a first vector value, for example, zero. Therefore, before the inversion recovery pulse is applied at the interval vector recovery time, the longitudinal magnetization vector of the detection object is recovered from the first vector value to the signal intensity of the vector recovery time, so that the longitudinal magnetization vectors of the detection object corresponding to different cardiac cycles are the same. This avoids the generation of artifacts in the magnetic resonance image caused by the inconsistency of the longitudinal magnetization vector before the application of multiple inversion recovery pulses in multiple target cardiac cycles, and is beneficial to improving the quality of the magnetic resonance image.

[0107] In one embodiment, the magnetic resonance data acquisition module 204 is specifically configured to apply the inversion recovery pulse in response to reaching the vector recovery time after the preparation module is applied; and apply a target scan sequence to the detection object in response to reaching the inversion recovery time after the inversion recovery pulse is applied, to obtain the magnetic resonance data of the detection object.

[0108] In one embodiment, the magnetic resonance data acquisition module 204 is specifically configured to apply a T2 preparation pulse to the detection object in response to reaching a set time after the preparation module is applied; and apply a target scan sequence to the detection object to obtain the magnetic resonance data of the detection object.

[0109] In one embodiment, the device further includes a signal acquisition module, a signal reconstruction module, and a magnetic resonance image processing module, wherein:

[0110] The signal acquisition module is configured to acquire a reference signal using a reference imaging sequence in a reference cardiac cycle in response to a preset waiting time after receiving an electrocardiogram trigger signal.

[0111] The signal reconstruction module is configured to reconstruct the reference signal to obtain a reference image.

[0112] The magnetic resonance image processing module is configured to obtain a phase-sensitive real part image according to the target magnetic resonance image and the reference image.

[0113] In one embodiment, the magnetic resonance image processing module is specifically configured to perform a registration operation on the target magnetic resonance image and the reference image; and perform phase-sensitive inversion recovery reconstruction on the registered target magnetic resonance image and the reference image to obtain the phase-sensitive real part image.

[0114] In one embodiment, the detected object is a heart; the signal acquisition module is specifically configured to, in a reference cardiac cycle, flip the second initial longitudinal magnetization vector corresponding to the heart into a second transverse magnetization vector in response to receiving a cardiac trigger signal, and the second vector value is in a dispersed phase; and in response to reaching a vector recovery time after the preparation module is applied, the reference signal is acquired using a reference imaging sequence.

[0115] The specific limitations on the magnetic resonance image generation apparatus can be referred to the limitations on the magnetic resonance image generation method in the foregoing, which will not be repeated here. Each module in the above magnetic resonance image generation apparatus can be realized by software, hardware and combinations thereof, in whole or in part. The above modules can be embedded in or independent of the processor in the computer device in hardware form, or can be stored in the memory in the computer device in software form, so as to be called and executed by the processor to perform the operations corresponding to the above modules.

[0116] In one embodiment, a computer device is provided, which can be a terminal, and the internal structure diagram thereof can be as shown in Figure 8 The computer device includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. The processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The communication interface of the computer device is configured to perform wired or wireless communication with an external terminal. The wireless communication can be achieved through WIFI, a carrier network, NFC (near field communication) or other technologies. The computer program is executed by the processor to implement a magnetic resonance image generation method. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer overlaid on the display screen, or a key, trackball or touchpad arranged on the shell of the computer device, or an external keyboard, touchpad or mouse, etc.

[0117] Those skilled in the art can understand that Figure 8 The structure shown in the above

[0118] In one embodiment, a computer device is provided, which includes a memory and a processor. The memory stores a computer program. The processor executes the computer program to implement the following steps:

[0119] The preparation module is applied in response to receiving the electrocardiogram trigger signal within the target cardiac cycle to flip a first initial longitudinal magnetization vector corresponding to the detection object into a first transverse magnetization vector and to scatter into a first vector value;

[0120] The magnetization preparation pulse is applied to the detection object, and the magnetic resonance data of the detection object is acquired after the magnetization preparation pulse is excited;

[0121] The magnetic resonance data is reconstructed to obtain the target magnetic resonance image of the detection object.

[0122] In the above computer device, the preparation module is applied in response to receiving the electrocardiogram trigger signal within the target cardiac cycle to flip a first initial longitudinal magnetization vector corresponding to the detection object into a first transverse magnetization vector and to scatter into a first vector value, for example, zero. In this way, it can be ensured that the longitudinal magnetization vector corresponding to the detection object is recovered from the first vector value to the signal intensity of the vector recovery time before the inversion recovery pulse is applied within the interval vector recovery time. The longitudinal magnetization vectors corresponding to different cardiac cycles of the detection object are the same, avoiding the generation of artifacts in the magnetic resonance image due to the inconsistency of the longitudinal magnetization vectors before applying multiple inversion recovery pulses within multiple target cardiac cycles, and facilitating the improvement of the quality of the magnetic resonance image.

[0123] In one embodiment, the processor executing the computer program further implements the following steps:

[0124] In response to reaching the vector recovery time after the preparation module is applied, an inversion recovery pulse is applied. In response to reaching the inversion recovery time after the inversion recovery pulse is applied, a target scan sequence is applied to the detection object to acquire magnetic resonance data of the detection object.

[0125] In one embodiment, the processor executing the computer program further implements the following steps:

[0126] In response to reaching the set time after the preparation module is applied, a T2 preparation pulse is applied to the detection object. A target scan sequence is applied to the detection object to acquire magnetic resonance data of the detection object.

[0127] In one embodiment, the processor executing the computer program further implements the following steps:

[0128] In the reference cardiac cycle, a reference signal is acquired using a reference imaging sequence in response to a preset waiting time after receiving the electrocardiogram trigger signal. The reference signal is reconstructed to obtain a reference image. The phase-sensitive real part image is obtained according to the target magnetic resonance image and the reference image.

[0129] In one embodiment, the processor executing the computer program further implements the following steps:

[0130] The target magnetic resonance image and the reference image are registered; and the registered target magnetic resonance image and the reference image are reconstructed by phase-sensitive inversion recovery to obtain a phase-sensitive real part image.

[0131] In one embodiment, the processor, when executing the computer program, also implements the following steps:

[0132] In the reference cardiac cycle, in response to receiving the electrocardio trigger signal, a preparation module is applied to flip the second initial longitudinal magnetization vector corresponding to the heart into a second transverse magnetization vector and to scatter into a second vector value; and in response to reaching the vector recovery time after the preparation module is applied, a reference signal is acquired using the reference imaging sequence.

[0133] In one embodiment, a computer-readable storage medium is provided, having stored thereon a computer program, which, when executed by a processor, implements the following steps:

[0134] In the target cardiac cycle, in response to receiving the electrocardio trigger signal, a preparation module is applied to flip the first initial longitudinal magnetization vector corresponding to the detection object into a first transverse magnetization vector and to scatter into a first vector value;

[0135] A magnetization preparation pulse is applied to the detection object, and after the magnetization preparation pulse is excited, magnetic resonance data of the detection object is acquired;

[0136] The magnetic resonance data is reconstructed to obtain a target magnetic resonance image of the detection object.

[0137] In the above computer-readable storage medium, by applying the preparation module after receiving the electrocardio trigger signal in the target cardiac cycle, the first initial longitudinal magnetization vector corresponding to the detection object is flipped into a first transverse magnetization vector, and scattered into a first vector value such as zero, so that the longitudinal magnetization vector corresponding to the detection object is recovered from the signal intensity of the first vector value to the vector recovery time before the inversion recovery pulse is applied within the interval vector recovery time, so that the longitudinal magnetization vectors corresponding to different cardiac cycles of the detection object are the same, avoiding the generation of artifacts in the magnetic resonance image due to the inconsistency of the longitudinal magnetization vectors before the application of multiple inversion recovery pulses in multiple target cardiac cycles, and facilitating the improvement of the quality of the magnetic resonance image.

[0138] In one embodiment, the computer program, when executed by the processor, also implements the following steps:

[0139] In response to reaching the vector recovery time after the preparation module is applied, an inversion recovery pulse is applied; and in response to reaching the inversion recovery time after the inversion recovery pulse is applied, a target scanning sequence is applied to the detection object to acquire magnetic resonance data of the detection object.

[0140] In one embodiment, the computer program, when executed by the processor, further implements the following steps:

[0141] In response to reaching a set time after the preparation module is applied, a T2 preparation pulse is applied to the detection object; a target scan sequence is applied to the detection object to obtain magnetic resonance data of the detection object.

[0142] In one embodiment, the computer program, when executed by the processor, further implements the following steps:

[0143] In the reference cardiac cycle, in response to a preset waiting time after the electrocardiogram trigger signal is received, a reference signal is obtained using a reference imaging sequence; the reference signal is reconstructed to obtain a reference image; and a phase-sensitive real part image is obtained according to the target magnetic resonance image and the reference image.

[0144] In one embodiment, the computer program, when executed by the processor, further implements the following steps:

[0145] The target magnetic resonance image and the reference image are registered; and phase-sensitive inversion recovery reconstruction is performed on the registered target magnetic resonance image and the reference image to obtain a phase-sensitive real part image.

[0146] In one embodiment, the computer program, when executed by the processor, further implements the following steps:

[0147] In the reference cardiac cycle, in response to receiving the electrocardiogram trigger signal, a preparation module is applied to flip a second initial longitudinal magnetization vector corresponding to the heart into a second transverse magnetization vector and to disperse into a second vector value; and in response to reaching a vector recovery time after the preparation module is applied, a reference signal is obtained using a reference imaging sequence.

[0148] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when executed, can include the processes of the above-mentioned embodiment methods. Any reference to memory, storage, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0149] Any combination of the technical features of the above embodiments can be made. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, but as long as the combination of the technical features does not exist, it should be considered as the scope of the present application.

[0150] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for those skilled in the art, without departing from the concept of the present application, some modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A method for generating magnetic resonance images, characterized in that, The method includes: Within the target cardiac cycle, in response to receiving an ECG trigger signal, a preparation module is applied to flip the first initial longitudinal magnetization vector corresponding to the detection object into a first transverse magnetization vector, and to dephasing the vector into a first vector value; the number of the target cardiac cycles is at least one, and the detection object includes the heart; A magnetization preparation pulse is applied to the object to be detected, and magnetic resonance data of the object to be detected is acquired after the magnetization preparation pulse is excited; the magnetization preparation pulse includes a T2 preparation pulse; The magnetic resonance data is reconstructed to obtain the target magnetic resonance image of the object being detected.

2. The method according to claim 1, characterized in that, Applying a magnetization preparation pulse to the object to be detected, and acquiring magnetic resonance data of the object to be detected after the magnetization preparation pulse is excited, includes: In response to the vector recovery time reached after the preparation module was applied, an inverse recovery pulse is applied; In response to the inversion recovery time after the inversion recovery pulse is applied, a target scan sequence is applied to the object being detected to obtain magnetic resonance data of the object being detected.

3. The method according to claim 1, characterized in that, Applying a magnetization preparation pulse to the object to be detected, and acquiring magnetic resonance data of the object to be detected after the magnetization preparation pulse is excited, includes: In response to the set time after the preparation module is applied, a T2 preparation pulse is applied to the detection object; A target scanning sequence is applied to the object being detected to obtain magnetic resonance data of the object.

4. The method according to claim 2, characterized in that, The method further includes: Within the reference cardiac cycle, in response to a preset waiting time after receiving an ECG trigger signal, a reference signal is acquired using a reference imaging sequence; The reference signal is reconstructed to obtain a reference image; Based on the target magnetic resonance image and the reference image, a phase-sensitive real part image is obtained.

5. The method according to claim 4, characterized in that, Based on the target magnetic resonance image and the reference image, a phase-sensitive real part image is obtained, including: The target magnetic resonance image and the reference image are registered. Phase-sensitive inversion recovery reconstruction is performed on the registered target magnetic resonance image and the reference image to obtain a phase-sensitive real part image.

6. The method according to claim 4, characterized in that, The object of detection is the heart; the step of acquiring a reference signal using a reference imaging sequence within a reference cardiac cycle, in response to a preset waiting time after receiving an electrocardiogram trigger signal, includes: During the reference cardiac cycle, in response to receiving an electrocardiogram trigger signal, a preparation module is applied to flip the second initial longitudinal magnetization vector corresponding to the heart into a second transverse magnetization vector, and to dephase it into a second vector value. In response to the vector recovery time after the preparation module is applied, a reference signal is acquired using the reference imaging sequence.

7. The method according to claim 5, characterized in that, The first K-space data corresponding to the target magnetic resonance image is obtained by filling in magnetic resonance data within multiple adjacent target cardiac cycles.

8. A magnetic resonance image generation device, characterized in that, The device includes: The preparation module application module is used to apply the preparation module in response to receiving an electrocardiogram trigger signal within the target cardiac cycle, so as to flip the first initial longitudinal magnetization vector corresponding to the detection object into a first transverse magnetization vector and dephasing it into a first vector value; the number of the target cardiac cycles is at least one, and the detection object includes the heart; A magnetic resonance data acquisition module is used to apply a magnetization preparation pulse to the object being detected, and to acquire the magnetic resonance data of the object being detected after the magnetization preparation pulse is excited; the magnetization preparation pulse includes a T2 preparation pulse; A magnetic resonance image generation module is used to reconstruct the magnetic resonance data to obtain a target magnetic resonance image of the detected object.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

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