Cardiac magnetic resonance diffusion tensor imaging method, apparatus, device and storage medium

Abstract

The application discloses a kind of cardiac magnetic resonance diffusion tensor imaging method, device, equipment and storage medium, the method comprises: obtaining the systolic detection sequence and diastolic detection sequence of multiple target myocardial layers of the person to be detected;Based on the systolic detection sequence and diastolic detection sequence, in the systole and diastole of the multiple heart cycles successively of the person to be detected respectively, each target myocardial layer is sequentially detected by magnetic resonance diffusion tensor imaging;Wherein, each systole and each diastole are respectively imaged to single target myocardial layer, and the minimum time interval between the systolic imaging and diastolic imaging of the same target myocardial layer is N heart cycle;N is integer and greater than or equal to 2.The application can improve the efficiency of the magnetic resonance diffusion tensor imaging of the heart under the premise of guaranteeing the signal-to-noise ratio of the cardiac magnetic resonance diffusion tensor imaging image.

Description

Technical Field

[0001] This invention relates to the field of magnetic resonance imaging technology, and in particular to a method, apparatus, device, and storage medium for cardiac magnetic resonance diffusion tensor imaging. Background Technology

[0002] Cardiac diffusion tensor imaging (DTI) can characterize early changes in myocardial microstructure. Changes in characteristic parameters during systole and diastole reflect changes in myocardial activity; therefore, acquiring these characteristic parameter changes is crucial for analyzing myocardial structural changes. In cardiac DTI models, multiple (generally more than 6, usually 10) images with different diffusion coding directions and one reference image without a diffusion coding gradient are needed for tensor fitting and quantitative parameter solving for each myocardial layer. Current cardiac DTI methods typically use stimulus-echo sequence imaging or spin-echo-planar-echo sequence imaging to acquire diffusion signals layer by layer, phase by phase. Stimulation-echo sequence imaging is less affected by cardiac motion, usually requires breath-holding for acquisition, and to ensure signal recovery of a single layer during imaging, the image signal-to-noise ratio is low, requiring two cardiac cycles (one cardiac cycle consists of one systolic and one diastolic phase) to acquire one image. While spin echo-plane echo sequence imaging can complete single-layer, single-direction, single-phase imaging within one cardiac cycle and does not require the subject to hold their breath during imaging, in order to ensure the recovery of single-layer signals during imaging, an image is usually acquired at intervals of one cardiac cycle, which means that acquiring a single image requires two cardiac cycles.

[0003] The above analysis shows that the commonly used cardiac diffusion tensor imaging method requires an imaging time of the number of layers * number of phases * single image acquisition time (2 cardiac cycles) for each diffusion-weighted direction when acquiring multi-layer, multi-phase, and multi-diffusion-weighted images of the heart. This results in an excessively long overall time for cardiac magnetic resonance diffusion tensor imaging, which limits the clinical application of this technology. Summary of the Invention

[0004] This invention provides a method, apparatus, device, and storage medium for cardiac magnetic resonance diffusion tensor imaging. It can achieve single-shot imaging of a single target myocardial layer during the systolic and diastolic phases of each cardiac cycle while ensuring a good signal-to-noise ratio in the cardiac magnetic resonance diffusion tensor imaging image, thereby improving the efficiency of cardiac magnetic resonance diffusion tensor imaging.

[0005] An embodiment of the present invention provides a method for cardiac magnetic resonance diffusion tensor imaging, comprising:

[0006] Obtain the systolic and diastolic detection sequences of multiple target myocardial layers from the subject of examination;

[0007] Based on the systolic and diastolic detection order, magnetic resonance diffusion tensor imaging was performed on each target myocardial layer during the systolic and diastolic phases of multiple consecutive cardiac cycles of the subject.

[0008] In this process, each systolic phase and each diastolic phase are used to perform a single imaging of a single target myocardial layer, and the time interval between the systolic imaging and the diastolic imaging of the same target myocardial layer is N cardiac cycles; N is an integer and is greater than or equal to 2.

[0009] As an improvement to the above scheme, the step of performing magnetic resonance diffusion tensor imaging on each target myocardial layer during the systolic and diastolic phases of multiple consecutive cardiac cycles of the subject, based on the systolic and diastolic detection sequences, includes:

[0010] Imaging of all the target myocardial layers was completed continuously under the same diffusion-weighted gradient direction;

[0011] The interval between systolic and diastolic imaging of the same target myocardial layer in the same diffusion-weighted gradient direction is N cardiac cycles.

[0012] As an improvement to the above scheme, the step of performing magnetic resonance diffusion tensor imaging on each target myocardial layer during the systolic and diastolic phases of multiple cardiac cycles of the subject based on the systolic and diastolic detection sequences includes:

[0013] Detect the electrocardiogram signal of the subject;

[0014] After detecting the specified waveform of the electrocardiogram signal, the systolic imaging of the target myocardial layer is triggered after a first preset time delay, and the diastolic imaging of the target myocardial layer is triggered after a second preset time delay.

[0015] The first preset time and the second preset time are preset based on the cardiac cine images of the subject being tested.

[0016] As an improvement to the above scheme, the step of performing magnetic resonance diffusion tensor imaging on each target myocardial layer during the systolic and diastolic phases of multiple cardiac cycles of the subject based on the systolic and diastolic detection sequences includes:

[0017] The layer excitation position of the target myocardial layer to be imaged is adjusted based on the respiratory navigation information of the subject in a free breathing state;

[0018] The target myocardial layer to be imaged is excited and imaged based on the adjusted layer excitation position.

[0019] As an improvement to the above scheme, the adjustment of the layer excitation position of the target myocardial layer to be imaged based on the respiratory navigation information of the subject in a free breathing state includes:

[0020] The current position of the subject's diaphragm is determined based on the respiratory navigation information;

[0021] Calculate the diaphragm displacement between the current position of the diaphragm and the reference diaphragm position obtained under standard conditions;

[0022] The heart displacement is calculated based on the diaphragm displacement and the preset heart-diaphragm displacement correlation coefficient.

[0023] The reference layer excitation position of the target myocardial layer to be imaged, obtained under the standard state, is adjusted based on the cardiac displacement.

[0024] As an improvement to the above scheme, the standard state is the breath-holding state at the end of expiration.

[0025] As an improvement to the above scheme, the step of obtaining the systolic and diastolic detection sequences of multiple target myocardial layers of the subject includes:

[0026] When the number of target myocardial layers is even, in one of the systolic detection order and the diastolic detection order, the target myocardial layers of odd number of layers are arranged first, followed by the target myocardial layers of even number of layers; in the other of the systolic detection order and the diastolic detection order, the target myocardial layers of even number of layers are arranged first, followed by the target myocardial layers of odd number of layers.

[0027] When the number of target myocardial layers is odd, in one of the systolic detection order and the diastolic detection order, the target myocardial layers of odd number are arranged first, followed by the target myocardial layers of even number; in the other of the systolic detection order and the diastolic detection order, the target myocardial layers of one odd number are arranged first, followed by the target myocardial layers of even number, and finally the target myocardial layers of the remaining odd number are arranged.

[0028] Another embodiment of the present invention provides a cardiac magnetic resonance diffusion tensor imaging device, comprising:

[0029] The myocardial layer detection sequence acquisition module is used to acquire the systolic and diastolic detection sequences of multiple target myocardial layers of the subject being tested.

[0030] The diffusion tensor imaging detection module is used to perform magnetic resonance diffusion tensor imaging detection on each target myocardial layer during the systolic and diastolic phases of multiple consecutive cardiac cycles of the subject, based on the systolic and diastolic detection sequences.

[0031] In this process, each systolic phase and each diastolic phase are used to perform a single imaging of a single target myocardial layer, and the time interval between the systolic imaging and the diastolic imaging of the same target myocardial layer is N cardiac cycles; N is an integer and is greater than or equal to 2.

[0032] Another embodiment of the present invention provides a cardiac magnetic resonance diffusion tensor imaging device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the cardiac magnetic resonance diffusion tensor imaging method described in the above-described embodiment of the invention.

[0033] Another embodiment of the present invention provides a storage medium, the computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to perform the cardiac magnetic resonance diffusion tensor imaging method described in the above-described embodiments of the invention.

[0034] Compared with existing technologies, one of the above technical solutions has at least one of the following advantages:

[0035] By performing magnetic resonance diffusion tensor imaging (MRI) on each target myocardial layer sequentially during the systolic and diastolic phases of multiple consecutive cardiac cycles based on the systolic and diastolic detection sequences of the subject, and by performing a single imaging of each target myocardial layer during each systolic and diastolic phase, the imaging efficiency is doubled compared to existing technologies. Furthermore, the time interval between systolic and diastolic imaging of the same target myocardial layer is at least two cardiac cycles, ensuring a good signal-to-noise ratio in the cardiac MRI diffusion tensor imaging images. Therefore, this invention improves the efficiency of cardiac MRI diffusion tensor imaging while maintaining a good signal-to-noise ratio in the cardiac MRI diffusion tensor imaging images. Attached Figure Description

[0036] Figure 1 This is a schematic flowchart of a cardiac magnetic resonance diffusion tensor imaging method according to an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of the systolic and diastolic imaging of the target myocardial layer in one embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the imaging sequence of target myocardial layers under different cardiac cycles with different diffusion weighting gradient directions in one embodiment of the present invention.

[0039] Figure 4This is an imaging image of each target myocardial layer during systole and diastole under one of the diffusion-weighted gradient directions in one embodiment of the present invention;

[0040] Figure 5 This is a schematic diagram of the structure of a cardiac magnetic resonance diffusion tensor imaging device according to an embodiment of the present invention;

[0041] Figure 6 This is a schematic diagram of the structure of a cardiac magnetic resonance diffusion tensor imaging device according to an embodiment of the present invention. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] See Figure 1 This is a schematic flowchart of a cardiac magnetic resonance diffusion tensor imaging method according to an embodiment of the present invention. The method is executed by a cardiac magnetic resonance diffusion tensor imaging device, and includes steps S10 to S11:

[0044] S10, obtain the systolic and diastolic detection sequences of multiple target myocardial layers of the subject.

[0045] S11, based on the systolic detection sequence and diastolic detection sequence, magnetic resonance diffusion tensor imaging is performed on each target myocardial layer during the systolic and diastolic phases of multiple consecutive cardiac cycles of the subject.

[0046] Each of the systolic and diastolic phases is used to image a single target myocardial layer, and the time interval between the systolic and diastolic imaging of the same target myocardial layer is N cardiac cycles; N is an integer and is greater than or equal to 2.

[0047] For example, in this step, imaging of all target myocardial layers can be completed consecutively under the same diffusion-weighted gradient direction; wherein, the interval between systolic and diastolic imaging of the same target myocardial layer under the same diffusion-weighted gradient direction is N cardiac cycles. It is understood that after imaging of all target myocardial layers under the diffusion-weighted gradient direction of the first target in each cardiac cycle is completed, the above process can be repeated until imaging of all target myocardial layers under the diffusion-weighted gradient direction of all targets in each cardiac cycle is completed.

[0048] In this embodiment of the invention, based on the systolic and diastolic detection sequences, magnetic resonance diffusion tensor imaging (MTI) is performed on each target myocardial layer during the systolic and diastolic phases of multiple consecutive cardiac cycles of the subject. Specifically, a single image of each target myocardial layer is performed during each systolic and diastolic phase, thus doubling the imaging efficiency compared to existing technologies. Furthermore, the time interval between systolic and diastolic imaging of the same target myocardial layer is at least two cardiac cycles, ensuring a good signal-to-noise ratio in the cardiac MTI images. Therefore, this embodiment of the invention improves the efficiency of cardiac MTI while maintaining a good signal-to-noise ratio in the cardiac MTI images.

[0049] In one embodiment, specifically, step S11 includes steps S110 to S111:

[0050] S110, Detect the electrocardiogram signal of the subject to be tested.

[0051] As an example, existing ECG trigger acquisition technology can be used to detect the current ECG signal of the subject.

[0052] S111, after detecting the specified waveform of the electrocardiogram signal, the systolic imaging of the target myocardial layer is triggered after a first preset time delay, and the diastolic imaging of the target myocardial layer is triggered after a second preset time delay; wherein, the first preset time and the second preset time are preset according to the cardiac cine images of the subject.

[0053] For example, the specified waveform is the R wave of an electrocardiogram (ECG) signal. See also Figure 2At the first preset time TD1 after each R-wave detection, the target myocardial layer enters the systolic phase (generally 0.1-0.3 seconds, but the duration varies among individuals), and imaging of the target myocardial layer during this phase is initiated. At the second preset time TD2 after each R-wave detection, the target myocardial layer enters the diastolic phase (generally 0.5-0.7 seconds, but the duration varies among individuals), and imaging of the target myocardial layer during this diastolic phase is initiated. Specifically, when imaging the target myocardial layer during systole or diastole, the imaging can be achieved using single-shot plane echo technology: after a 90° pulse excitation at the excitation location, a preset diffusion-weighted gradient pulse is applied, followed by a 180° pulse to refocus the initially diffused signal; a preset diffusion-weighted gradient pulse is applied to the refocused signal to obtain a diffusion-weighted myocardial signal; the diffusion-weighted myocardial signal of the subject's heart is acquired using single-shot plane echo technology, and finally, a diffusion-weighted image of the currently selected myocardial layer under the current diffusion-weighted gradient direction is obtained through reconstruction.

[0054] As an example, the process of setting the first preset time and the second preset time based on the cardiac cine image of the subject can be referred to existing cardiac cine image analysis techniques, and will not be elaborated here.

[0055] In one embodiment, specifically, step S11 includes steps S110' to S111':

[0056] S110', Based on the respiratory navigation information of the subject in a free breathing state, adjust the layer excitation position of the target myocardial layer to be imaged.

[0057] Specifically, step S110' includes steps S1100' to S1100':

[0058] S1100', determine the current position of the diaphragm of the subject based on the respiratory navigation information;

[0059] S1101', Calculate the diaphragm displacement between the current position of the diaphragm and the reference diaphragm position obtained under standard conditions;

[0060] S1102', calculate the heart displacement based on the diaphragm displacement and the preset heart-diaphragm displacement correlation coefficient;

[0061] S1103', Based on the cardiac displacement, adjust the reference layer excitation position of the target myocardial layer to be imaged under the standard state.

[0062] S111', based on the adjusted layer excitation position, excite and image the target myocardial layer to be imaged.

[0063] In this embodiment, under free breathing conditions, by combining spin echo-planar echo imaging with respiratory navigation tracking technology, the current cardiac displacement is calculated using the diaphragm displacement between the current position of the diaphragm and the reference diaphragm position under standard conditions, along with a preset heart-diaphragm displacement correlation coefficient. Then, based on this cardiac displacement, the reference excitation position of the target myocardial layer obtained under standard conditions is adjusted. This enables normal cardiac magnetic resonance diffusion tensor imaging of the subject under free breathing conditions. Therefore, using this embodiment, the subject does not need to hold their breath during cardiac magnetic resonance diffusion tensor imaging, thus requiring less patient compliance and improving patient comfort.

[0064] As an example, the correlation coefficient between heart and diaphragm displacement is 0.6. It is understood that the correlation coefficient can also be calculated using a personalized fitting method, making the correlation coefficient more consistent with the current subject of the test.

[0065] As an example, the standard state is the breath-holding state at the end of expiration.

[0066] In one embodiment, specifically, step S10 includes:

[0067] When the number of target myocardial layers is even, in one of the systolic detection order and the diastolic detection order, the target myocardial layers of odd number of layers are arranged first, followed by the target myocardial layers of even number of layers; in the other of the systolic detection order and the diastolic detection order, the target myocardial layers of even number of layers are arranged first, followed by the target myocardial layers of odd number of layers.

[0068] When the number of target myocardial layers is odd, in one of the systolic detection order and the diastolic detection order, the target myocardial layers of odd number are arranged first, followed by the target myocardial layers of even number; in the other of the systolic detection order and the diastolic detection order, the target myocardial layers of one odd number are arranged first, followed by the target myocardial layers of even number, and finally the target myocardial layers of the remaining odd number are arranged.

[0069] For ease of understanding, as an example, the systolic and diastolic detection sequences for each target myocardial layer are shown in Table 1. This ensures that the diffusion signal for diffusion tensor imaging of the myocardium has a recovery time of at least two cardiac cycles, thereby guaranteeing a good signal-to-noise ratio for the cardiac magnetic resonance diffusion tensor imaging image. For example, referring to Table 1, when there are 6 target myocardial layers, in the systolic detection sequence, the odd-numbered myocardial layers 1, 5, and 3 are arranged first, followed by the even-numbered myocardial layers 6, 2, and 4; in the diastolic detection sequence, the even-numbered layers 6, 2, and 4 are arranged first, followed by the odd-numbered layers 1, 5, and 3. This ensures that the diffusion signal for diffusion tensor imaging of the myocardium has a recovery time of at least two cardiac cycles. Of course, when the number of target myocardial layers is 6, in the systolic detection sequence, even-numbered layers 6, 2, and 4 can be arranged first, followed by odd-numbered layers 1, 5, and 3; in the diastolic detection sequence, odd-numbered myocardial layers 1, 5, and 3 can be arranged first, followed by even-numbered myocardial layers 6, 2, and 4.

[0070] Table 1. Examples of the systolic and diastolic detection sequences for each target myocardial layer

[0071]

[0072]

[0073] After imaging the target myocardial layers during systole and diastole in one diffusion-weighted gradient direction, another image of the target myocardial layers during systole and diastole in the next diffusion-weighted gradient direction is imaged. For ease of understanding, the following example illustrates this:

[0074] See Figure 3 Taking a scenario where there are 5 target myocardial layers requiring diffusion tensor imaging as an example, it would require 5 cardiac cycles to image the target myocardial layer under each diffusion-weighted gradient direction. For instance, the number of cardiac cycles under the first diffusion-weighted gradient direction (D1) is... Figure 3 The first five cardiac cycles are shown. During the first diffusion-weighted gradient direction (D1) diffusion tensor imaging, the systolic phases of the first, fifth, third, second, and fourth target myocardial layers (S1, S5, S3, S2, S4) and the diastolic phases of the third, second, fourth, fifth, and first myocardial layers (S3, S2, S4, S5, S1) are successively imaged, ensuring that the time interval between the systolic and diastolic imaging of the same target myocardial layer is two cardiac cycles. Please refer to the image of each target myocardial layer for details. Figure 4The diffusion tensor imaging (DTI) of the target myocardial layers during the systolic and diastolic phases of each cardiac cycle can be performed in the second diffusion-weighted gradient direction (D2) and the remaining diffusion-weighted gradient directions, following the process described above. Using this method, with diffusion tensor imaging of 5 target myocardial layers and 10 diffusion-weighted directions, the imaging time is a total of 5*10 = 50 cardiac cycles (a human cardiac cycle is generally less than 1 second). DTI imaging of 5 myocardial layers during the systolic and diastolic phases in 10 diffusion-weighted directions can be completed within 1 minute. In contrast, the traditional method, calculated as: number of layers * number of diffusion-weighted directions * number of phases * single image acquisition time (2 cardiac cycles), requires 5*10*2*2 = 200 cardiac cycles.

[0075] See Figure 5 This is a schematic diagram of a cardiac magnetic resonance diffusion tensor imaging device according to an embodiment of the present invention. The device includes:

[0076] The myocardial layer detection sequence acquisition module 10 is used to acquire the systolic and diastolic detection sequences of multiple target myocardial layers of the subject being tested.

[0077] The diffusion tensor imaging detection module 11 is used to perform magnetic resonance diffusion tensor imaging detection on each target myocardial layer during the systolic and diastolic phases of multiple consecutive cardiac cycles of the subject, based on the systolic detection sequence and the diastolic detection sequence.

[0078] In this process, each systolic phase and each diastolic phase are used to perform a single imaging of a single target myocardial layer, and the time interval between the systolic imaging and the diastolic imaging of the same target myocardial layer is N cardiac cycles; N is an integer and is greater than or equal to 2.

[0079] In this embodiment of the invention, based on the systolic and diastolic detection sequences, magnetic resonance diffusion tensor imaging (MTI) is performed on each target myocardial layer during the systolic and diastolic phases of multiple consecutive cardiac cycles of the subject. Specifically, a single image of each target myocardial layer is performed during each systolic and diastolic phase, thus doubling the imaging efficiency compared to existing technologies. Furthermore, the time interval between systolic and diastolic imaging of the same target myocardial layer is at least two cardiac cycles, ensuring a good signal-to-noise ratio in the cardiac MTI images. Therefore, this embodiment of the invention improves the efficiency of cardiac MTI while maintaining a good signal-to-noise ratio in the cardiac MTI images.

[0080] As an improvement to the above embodiments, the diffusion tensor imaging detection module 11 is specifically used for:

[0081] Imaging of all the target myocardial layers was completed continuously under the same diffusion-weighted gradient direction;

[0082] The interval between systolic and diastolic imaging of the same target myocardial layer in the same diffusion-weighted gradient direction is N cardiac cycles.

[0083] As an improvement to the above embodiments, the diffusion tensor imaging detection module 11 is specifically used for:

[0084] Detect the electrocardiogram signal of the subject;

[0085] After detecting the specified waveform of the electrocardiogram signal, the systolic imaging of the target myocardial layer is triggered after a first preset time delay, and the diastolic imaging of the target myocardial layer is triggered after a second preset time delay.

[0086] The first preset time and the second preset time are preset based on the cardiac cine images of the subject being tested.

[0087] As an improvement to the above embodiments, the diffusion tensor imaging detection module is specifically used for:

[0088] The layer excitation position of the target myocardial layer to be imaged is adjusted based on the respiratory navigation information of the subject in a free breathing state;

[0089] The target myocardial layer to be imaged is excited and imaged based on the adjusted layer excitation position.

[0090] As an improvement to the above embodiments, more specifically, the diffusion tensor imaging detection module 11 is used for:

[0091] The current position of the subject's diaphragm is determined based on the respiratory navigation information;

[0092] Calculate the diaphragm displacement between the current position of the diaphragm and the reference diaphragm position obtained under standard conditions;

[0093] The heart displacement is calculated based on the diaphragm displacement and the preset heart-diaphragm displacement correlation coefficient.

[0094] The reference layer excitation position of the target myocardial layer to be imaged, obtained under the standard state, is adjusted based on the cardiac displacement.

[0095] As an improvement to the above embodiment, the standard state is the breath-holding state at the end of expiration.

[0096] As an improvement to the above embodiment, the myocardial layer detection sequence acquisition module 10 is specifically used for:

[0097] When the number of target myocardial layers is even, in one of the systolic detection order and the diastolic detection order, the target myocardial layers of odd number of layers are arranged first, followed by the target myocardial layers of even number of layers; in the other of the systolic detection order and the diastolic detection order, the target myocardial layers of even number of layers are arranged first, followed by the target myocardial layers of odd number of layers.

[0098] When the number of target myocardial layers is odd, in one of the systolic detection order and the diastolic detection order, the target myocardial layers of odd number are arranged first, followed by the target myocardial layers of even number; in the other of the systolic detection order and the diastolic detection order, the target myocardial layers of one odd number are arranged first, followed by the target myocardial layers of even number, and finally the target myocardial layers of the remaining odd number are arranged.

[0099] It should be noted that the embodiments of the cardiac magnetic resonance diffusion tensor imaging devices described above can be referred to the relevant content of the embodiments of the cardiac magnetic resonance diffusion tensor imaging method described above, and will not be repeated here.

[0100] See Figure 6 This is a schematic diagram of a cardiac magnetic resonance diffusion tensor imaging (MRI) device according to an embodiment of the present invention. The cardiac MRI device of this embodiment includes: a processor 100, a memory 101, and a computer program stored in the memory 101 and executable on the processor 100, such as a cardiac MRI diffusion tensor imaging program. When the processor 100 executes the computer program, it implements the steps in the various cardiac MRI diffusion tensor imaging method embodiments described above, for example... Figure 1 The steps shown are for cardiac magnetic resonance diffusion tensor imaging. Alternatively, when the processor 100 executes the computer program, it implements the functions of each module / unit in the above-described device embodiments, such as cardiac magnetic resonance diffusion tensor imaging.

[0101] For example, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in the cardiac magnetic resonance diffusion tensor imaging device.

[0102] The cardiac magnetic resonance diffusion tensor imaging device may include, but is not limited to, a processor and a memory. Those skilled in the art will understand that the schematic diagram is merely an example of a cardiac magnetic resonance diffusion tensor imaging device and does not constitute a limitation on the device. It may include more or fewer components than illustrated, or combine certain components, or use different components. For example, the cardiac magnetic resonance diffusion tensor imaging device may also include input / output devices, network access devices, buses, etc.

[0103] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor. This processor is the control center of the cardiac magnetic resonance diffusion tensor imaging device, connecting all parts of the device via various interfaces and lines.

[0104] The memory can be used to store the computer programs and / or modules. The processor implements various functions of the cardiac magnetic resonance diffusion tensor imaging device by running or executing the computer programs and / or modules stored in the memory and by calling the data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created based on the use of the mobile phone (such as audio data, phonebook, etc.). In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital card (SD) card, flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0105] If the modules / units integrated into the cardiac magnetic resonance diffusion tensor imaging device are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content contained in the computer-readable medium may be appropriately added to or subtracted from the content as required by the legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium may not include electrical carrier signals and telecommunication signals.

[0106] It should be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0107] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for cardiac magnetic resonance diffusion tensor imaging, characterized in that, include: Obtain the systolic and diastolic detection sequences of multiple target myocardial layers from the subject of examination; Based on the systolic and diastolic detection order, magnetic resonance diffusion tensor imaging was performed on each target myocardial layer during the systolic and diastolic phases of multiple consecutive cardiac cycles of the subject. Each systolic phase and each diastolic phase are used to image a single target myocardial layer, and the time interval between systolic and diastolic imaging of the same target myocardial layer is N cardiac cycles; N is an integer and is greater than or equal to 2. The acquisition of the systolic and diastolic detection sequences of multiple target myocardial layers of the subject includes: When the number of target myocardial layers is even, in one of the systolic detection order and the diastolic detection order, the target myocardial layers of odd number of layers are arranged first, followed by the target myocardial layers of even number of layers; in the other of the systolic detection order and the diastolic detection order, the target myocardial layers of even number of layers are arranged first, followed by the target myocardial layers of odd number of layers. When the number of target myocardial layers is odd, in one of the systolic detection order and the diastolic detection order, the target myocardial layers of odd number are arranged first, followed by the target myocardial layers of even number; in the other of the systolic detection order and the diastolic detection order, the target myocardial layers of one odd number are arranged first, followed by the target myocardial layers of even number, and finally the target myocardial layers of the remaining odd number are arranged.

2. The cardiac magnetic resonance diffusion tensor imaging method as described in claim 1, wherein the step of performing magnetic resonance diffusion tensor imaging detection on each target myocardial layer during the systolic and diastolic phases of multiple consecutive cardiac cycles of the subject based on the systolic and diastolic detection sequences comprises: Imaging of all the target myocardial layers was completed continuously under the same diffusion-weighted gradient direction; The interval between systolic and diastolic imaging of the same target myocardial layer in the same diffusion-weighted gradient direction is N cardiac cycles.

3. The cardiac magnetic resonance diffusion tensor imaging method as described in claim 1, wherein the step of performing magnetic resonance diffusion tensor imaging detection on each target myocardial layer during the systolic and diastolic phases of multiple cardiac cycles of the subject based on the systolic and diastolic detection sequences comprises: Detect the electrocardiogram signal of the subject; After detecting the specified waveform of the electrocardiogram signal, the systolic imaging of the target myocardial layer is triggered after a first preset time delay, and the diastolic imaging of the target myocardial layer is triggered after a second preset time delay. The first preset time and the second preset time are preset based on the cardiac cine images of the subject being tested.

4. The cardiac magnetic resonance diffusion tensor imaging method as described in claim 1, wherein the step of performing magnetic resonance diffusion tensor imaging detection on each target myocardial layer during the systolic and diastolic phases of multiple cardiac cycles of the subject based on the systolic and diastolic detection sequences comprises: The layer excitation position of the target myocardial layer to be imaged is adjusted based on the respiratory navigation information of the subject in a free breathing state; The target myocardial layer to be imaged is excited and imaged based on the adjusted layer excitation position.

5. The cardiac magnetic resonance diffusion tensor imaging method as described in claim 4, characterized in that, The adjustment of the layer excitation position of the target myocardial layer to be imaged based on the respiratory navigation information of the subject under free breathing includes: The current position of the diaphragm of the subject is determined based on the respiratory navigation information; Calculate the diaphragm displacement between the current position of the diaphragm and the reference diaphragm position obtained under standard conditions; The heart displacement is calculated based on the diaphragm displacement and the preset heart-diaphragm displacement correlation coefficient. The excitation position of the target myocardial layer to be imaged, obtained under the standard state, is adjusted based on the cardiac displacement.

6. The cardiac magnetic resonance diffusion tensor imaging method as described in claim 5, characterized in that, The standard state is the breath-holding state at the end of expiration.

7. A cardiac magnetic resonance diffusion tensor imaging device, characterized in that, include: A myocardial layer detection order acquisition module is used to acquire the systolic and diastolic detection order of multiple target myocardial layers of a subject under test. The acquisition of the systolic and diastolic detection order of multiple target myocardial layers includes: when the number of target myocardial layers is even, in one of the systolic and diastolic detection orders, first arranging the odd-numbered target myocardial layers, then arranging the even-numbered target myocardial layers; in the other of the systolic and diastolic detection orders, first arranging the even-numbered target myocardial layers, then arranging the odd-numbered target myocardial layers; when the number of target myocardial layers is odd, in one of the systolic and diastolic detection orders, first arranging the odd-numbered target myocardial layers, then arranging the even-numbered target myocardial layers; in the other of the systolic and diastolic detection orders, first arranging one odd-numbered target myocardial layer, then arranging the even-numbered target myocardial layers, and finally arranging the remaining odd-numbered target myocardial layers. The diffusion tensor imaging detection module is used to perform magnetic resonance diffusion tensor imaging detection on each target myocardial layer during the systolic and diastolic phases of multiple consecutive cardiac cycles of the subject, based on the systolic and diastolic detection sequences. Each of the systolic and diastolic phases is used to image a single target myocardial layer, and the time interval between the systolic and diastolic imaging of the same target myocardial layer is N cardiac cycles; N is an integer and is greater than or equal to 2.

8. A cardiac magnetic resonance diffusion tensor imaging device, characterized in that, It includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the cardiac magnetic resonance diffusion tensor imaging method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored computer program, wherein, when the computer program is executed, it controls the device on which the computer-readable storage medium is located to perform the cardiac magnetic resonance diffusion tensor imaging method as described in any one of claims 1 to 6.

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