Multi-phase heart image acquisition method and device, equipment and storage medium
By acquiring and processing the heart image using different flip angles when collecting heart movies in multi-coils, the non-uniform signal problem caused by the near-coil effect is solved, and high-quality multi-phase heart images are achieved.
Patent Information
- Application Number
- CN202311470461.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-06
- Publication Date
- 2025-05-06
AI Technical Summary
When collecting cardiac movie imaging with multi-coil, there is an inhomogeneous signal caused by near-coil effect, which affects the observation of multi-phase cardiac images.
By acquiring the to-merged heart images of the multi-phase phase corresponding to the multi-channel according to the first flip angle, and performing channel merging of the to-merged heart images of the same phase phase, a reference heart image is obtained. Then, the cardiac image to be uniformized is acquired according to the second flip angle, and the cardiac image to be uniformized based on the reference cardiac image to obtain a target cardiac image.
Effectively eliminate the heterogeneous signals caused by near-coil effect, retain the contrast signal reflecting the difference in T1 value, and improve the quality of multi-phase heart images.
Smart Images
Figure CN119941922A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of magnetic resonance imaging, and in particular to a method, apparatus, computer equipment, storage medium and computer program product for acquiring multi-phase cardiac images. Background Art
[0002] Cardiac cine imaging is one of the techniques for cardiac function imaging. Through cardiac cine imaging, multi-phase cardiac images within the cardiac cycle can be obtained.
[0003] When multiple coils are used to collect magnetic resonance signals for cardiac cine imaging, there is a near-coil effect, which causes multi-phase cardiac images to contain non-uniform signals caused by the near-coil effect, affecting observation. Summary of the invention
[0004] Based on this, it is necessary to provide a method, apparatus, computer equipment, storage medium and computer program product for acquiring multi-phase cardiac images in order to solve the above technical problems.
[0005] The present application provides a method for acquiring a multi-phase cardiac image, the method comprising:
[0006] According to the first flip angle, a cardiac image to be merged of multiple phases corresponding to multiple channels is obtained;
[0007] Performing channel merging on the cardiac images to be merged in the same phase to obtain reference cardiac images in multiple phases;
[0008] According to a second flip angle, a multi-phase cardiac image to be homogenized is obtained; the second flip angle is greater than the first flip angle;
[0009] The cardiac image to be homogenized is homogenized based on the reference cardiac image of the same phase to obtain a target cardiac image of multiple phases.
[0010] In one embodiment, the step of performing channel merging on the cardiac images to be merged in the same phase to obtain reference cardiac images in multiple phases includes:
[0011] Merging channels of the cardiac images to be merged in the same phase to obtain a fused cardiac image of multiple phases;
[0012] The multi-phase fused cardiac image is filtered to obtain a multi-phase reference cardiac image.
[0013] In one embodiment, before obtaining the multi-phase cardiac images to be merged corresponding to the multi-channels according to the first flip angle, the method further includes:
[0014] Obtain the ease with which the longitudinal magnetization of protons recovers to a steady state after being acted upon at different flip angles;
[0015] The first flip angle is determined according to the ease; the higher the ease, the greater the probability of being selected as the first flip angle.
[0016] In one embodiment, obtaining a multi-phase cardiac image to be homogenized according to the second flip angle includes:
[0017] After acquiring magnetic resonance data based on the first flip angle, performing an empty scan based on the second flip angle;
[0018] When the duration of the empty scan is at least one cardiac cycle, magnetic resonance data acquisition is performed;
[0019] The collected data are reconstructed to obtain a multi-phase cardiac image to be homogenized.
[0020] In one embodiment, the step of performing a homogenization process on the cardiac image to be homogenized based on the reference cardiac image of the same phase to obtain a target cardiac image of multiple phases includes:
[0021] Based on the reference cardiac image of the same phase, eliminating the non-uniform signal caused by the near-coil effect in the cardiac image to be homogenized;
[0022] A target cardiac image with multiple phases is obtained according to the cardiac image to be homogenized after each phase is eliminated.
[0023] In one embodiment, the removing of the non-uniform signal caused by the near-coil effect in the cardiac image to be homogenized based on the reference cardiac image of the same phase includes:
[0024] The cardiac image to be homogenized in the same phase is divided by the reference cardiac image to eliminate the non-homogeneous signal caused by the near-coil effect in the cardiac image to be homogenized.
[0025] In one embodiment, obtaining the cardiac images to be merged of multiple phases corresponding to multiple channels according to the first flip angle includes:
[0026] Acquiring magnetic resonance data of at least one cardiac cycle based on the first flip angle;
[0027] The collected data are reconstructed to obtain a multi-phase cardiac image to be merged corresponding to multiple channels.
[0028] The present application provides a device for acquiring a multi-phase cardiac image, the device comprising:
[0029] A first image acquisition module, used for obtaining a cardiac image to be merged of multiple phases corresponding to multiple channels according to a first flip angle;
[0030] A reference image acquisition module, used for performing channel merging on the cardiac images to be merged in the same phase to obtain reference cardiac images in multiple phases;
[0031] A second image acquisition module, used for obtaining a multi-phase cardiac image to be homogenized according to a second flip angle; the second flip angle is greater than the first flip angle;
[0032] The homogenization processing module is used to perform homogenization processing on the cardiac image to be homogenized based on the reference cardiac image of the same phase to obtain a target cardiac image of multiple phases.
[0033] The present application provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the above method.
[0034] The present application provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to execute the above method.
[0035] The present application provides a computer program product, on which a computer program is stored, and the computer program is executed by a processor to perform the above method.
[0036] Based on the difference in T1 values (Longitudinal Relaxation Time) at different positions of the heart, cardiac movie imaging can be performed to obtain a multi-phase cardiac image. Therefore, the present application obtains a multi-phase cardiac image to be homogenized based on a larger second flip angle. The cardiac image to be homogenized contains a contrast signal reflecting the difference in T1 values and a non-homogeneous signal caused by the near-coil effect (the non-homogeneous signal is an inhomogeneous signal). In order to eliminate non-uniform signals, the present application obtains multi-phase cardiac images to be merged corresponding to multiple channels based on a smaller first flip angle, and performs channel merging on the cardiac images to be merged of the same phase to obtain a multi-phase reference cardiac image. Since the first flip angle is smaller, the longitudinal magnetization of protons at different positions of the heart recovers to a steady state faster after the first flip angle acts. Therefore, in the magnetic resonance signals collected by the multiple coils, there are fewer contrast signals reflecting the difference in T1 values, and more non-uniform signals caused by the near-coil effect. Therefore, the reference cardiac image of each phase mainly contains non-uniform signals caused by the near-coil effect. With the help of the multi-phase reference cardiac images, the multi-phase cardiac images to be homogenized are homogenized, so that the non-uniform signals caused by the near-coil effect in the multi-phase cardiac images to be homogenized can be eliminated, and a multi-phase target cardiac image can be obtained, which mainly contains a contrast signal reflecting the difference in T1 values. BRIEF DESCRIPTION OF THE DRAWINGS
[0037] Figure 1 A schematic diagram of multiple phases of a cardiac cycle in one embodiment;
[0038] Figure 2 is a schematic flow chart of a method for acquiring a multi-phase cardiac image in one embodiment;
[0039] Figure 3 A schematic diagram of a sequence used for cardiac cine imaging in one embodiment;
[0040] Figure 4 A schematic diagram of a Tagging sequence used for cardiac cine imaging in one embodiment;
[0041] Figure 5 A schematic diagram of an image obtained by a stripe tagging sequence in one embodiment;
[0042] Figure 6 A schematic diagram of an image obtained by a grid-shaped Tagging sequence in one embodiment;
[0043] Figure 7 A schematic diagram of the contrast of images obtained at a small flip angle and a large flip angle in one embodiment;
[0044] Figure 8 is a structural block diagram of a device for acquiring a multi-phase cardiac image in one embodiment;
[0045] Fig. 9 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION
[0046] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
[0047] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.
[0048] A typical magnetic resonance imaging system includes the following components: magnet, gradient coil, radio frequency transmitting coil, radio frequency receiving coil, and signal processing and image reconstruction unit. The proton spin in the human body can be equivalent to a small magnetic needle. In the strong magnetic field provided by the magnet, the proton changes from a disordered thermal equilibrium state to a state partially in the direction of the main magnetic field and partially in the opposite direction. The difference between the two forms the net magnetization vector. The proton precesses around the main magnetic field, and the precession frequency is proportional to the magnetic field strength. The gradient unit generates a magnetic field whose intensity varies with the spatial position, which is used for spatial encoding of the signal. The radio frequency transmitting coil flips the proton from the main magnetic field direction to the transverse plane and precesses around the main magnetic field. A current signal is induced in the radio frequency receiving coil. The image of the imaged tissue is obtained through the signal processing and image reconstruction unit.
[0049] In order to observe the beating of the heart, cardiac cine imaging can be used to obtain images of the heart in different phases of the cardiac cycle, that is, multi-phase cardiac images; cardiac cine imaging includes prospective cine imaging and retrospective cine imaging.
[0050] Specifically, refer to Figure 1 The heart can collect some K-space data lines at phase 1 of the N-1th cardiac cycle, the heart can collect some K-space data lines at phase 1 of the Nth cardiac cycle, and the heart can collect some K-space data lines at phase 1 of the N+1th cardiac cycle; based on the K-space data lines collected by the heart at phase 1 of different cardiac cycles, an image of the heart at phase 1 is obtained; in this way, images of the heart at other phases can be obtained, thereby obtaining a multi-phase heart image.
[0051] The method for acquiring multi-phase cardiac images provided in the present application can remove the non-uniform signal caused by the near coil effect in the cardiac image and retain the contrast signal reflecting the difference in T1 value. The method can be executed by a computer device, including Figure 2 The steps shown are:
[0052] Step S201: obtaining a cardiac image to be merged of multiple phases corresponding to multiple channels according to a first flip angle.
[0053] Compared with the flip angle used to collect contrast signals reflecting T1 value differences (such as the second flip angle of the present application), the first flip angle is a small flip angle, and the longitudinal magnetization of protons can recover to a steady state more quickly under the action of the first flip angle.
[0054] Taking the receiving coil including M coils as an example, each coil corresponds to a receiving channel. After applying the excitation pulse of the first flip angle, the magnetic resonance signal collected by the first coil can be obtained. The magnetic resonance signal is transmitted through the receiving channel and phase-encoded to obtain the K-space data line in phase 1. Based on the K-space data line, reconstruction is performed to obtain the heart image R of the receiving channel corresponding to the first coil in phase 1. 1_1 In order to distinguish the cardiac images in other steps, this cardiac image is called the cardiac image to be merged. According to this method, the cardiac images to be merged of the receiving channels corresponding to the second coil to the Mth coil in phase 1 can be obtained, thereby obtaining the cardiac images to be merged of the receiving channels corresponding to the M coils in phase 1 {R 1_1 , R 1_2 , ..., R 1_M}.
[0055] According to the above method, the heart image {R i_1 , R i_2 , ..., R i_M}.
[0056] Step S202 , performing channel merging on the cardiac images to be merged in the same phase to obtain reference cardiac images of multiple phases.
[0057] After obtaining the heart images to be merged in multiple phases of the receiving channels corresponding to the M coils, the heart images to be merged acquired by the multiple receiving channels in the same phase can be merged to obtain a reference heart image of the phase. For example, the heart images to be merged in phase 1 of the receiving channels corresponding to the M coils {R 1_1 , R 1_2 , ..., R 1_M} to obtain the reference cardiac image of phase 1 (denoted as R1), and the cardiac image {R i_1 , R i_2 , ..., R i_M} to obtain the reference cardiac image of phase i (denoted as R i ).
[0058] In the above manner, multiple phases of reference cardiac images {R1, R2, . . . , R i}.
[0059] Since the first flip angle is a small flip angle, the longitudinal magnetization of the proton can recover to a steady state relatively quickly under the action of the first flip angle. Therefore, the reference cardiac image of each phase mainly contains the non-uniform signal caused by the near-coil effect, and the contrast signal reflecting the difference in T1 values is relatively small.
[0060] Step S203, obtaining a multi-phase cardiac image to be homogenized according to a second flip angle; the second flip angle is greater than the first flip angle.
[0061] The second flip angle is a flip angle for collecting contrast signals reflecting T1 value differences, and is a large flip angle. For example, after applying an excitation pulse with the second flip angle, the magnetic resonance signal collected by the first coil can be obtained, and the magnetic resonance signal is transmitted through the receiving channel and phase-encoded to obtain a K-space data line in phase 1. Reconstruction is performed based on the K-space data line to obtain a cardiac image I of the receiving channel corresponding to the first coil in phase 1. 1_1 In this way, the cardiac images of the receiving channels corresponding to the second coil to the Mth coil in phase 1 can be obtained. 1_2 ,......,I 1_M}; Then, the receiving channels corresponding to the first coil to the Mth coil are respectively in phase 1 {I 1_1 , I 1_2 ,......,I 1_M} to perform channel merging, and obtain the cardiac image I1 of phase 1. In order to distinguish the cardiac images in other steps, this cardiac image can be called the cardiac image to be homogenized. According to the above method, the cardiac images to be homogenized {I2, ..., I i}, thereby forming the cardiac images {I1, I2, ..., I i}.
[0062] Step S204: performing homogenization processing on the cardiac image to be homogenized based on the reference cardiac image of the same phase to obtain a target cardiac image of multiple phases.
[0063] After obtaining a multi-phase reference cardiac image {R1, R2, ..., R i} and the cardiac image to be homogenized {I1, I2, ..., I i}, for a cardiac image to be homogenized in a certain phase, the reference cardiac image of the phase can be used to perform homogenization processing on the cardiac image to be homogenized in the phase, so as to obtain a target cardiac image of the phase (which can be recorded as UI); for example, R i to I i Perform homogenization and remove I i The non-uniform signal caused by the near coil effect is used to obtain the target heart image UI of phase i. i , the target cardiac image mainly contains contrast signals reflecting the difference in T1 values.
[0064] This embodiment obtains a multi-phase cardiac image to be homogenized based on a larger second flip angle. The cardiac image to be homogenized contains a contrast signal reflecting a difference in T1 values and a non-homogeneous signal caused by a near-coil effect. In order to eliminate non-uniform signals, the present application obtains multi-phase cardiac images to be merged corresponding to multiple channels based on a smaller first flip angle, and performs channel merging on the cardiac images to be merged of the same phase to obtain a multi-phase reference cardiac image. Since the first flip angle is smaller, the longitudinal magnetization of protons at different positions of the heart recovers to a steady state faster after the first flip angle acts. Therefore, in the magnetic resonance signals collected by the multiple coils, there are fewer contrast signals reflecting the difference in T1 values, and more non-uniform signals caused by the near-coil effect. Therefore, the reference cardiac image of each phase mainly contains non-uniform signals caused by the near-coil effect. With the help of the multi-phase reference cardiac images, the multi-phase cardiac images to be homogenized are homogenized, so that the non-uniform signals caused by the near-coil effect in the multi-phase cardiac images to be homogenized can be eliminated, and a multi-phase target cardiac image can be obtained, which mainly contains a contrast signal reflecting the difference in T1 values.
[0065] In one embodiment, step S202 of performing channel merging on the cardiac images to be merged in the same phase to obtain a reference cardiac image of multiple phases includes: performing channel merging on the cardiac images to be merged in the same phase to obtain a fused cardiac image of multiple phases; and performing filtering processing on the fused cardiac image of multiple phases to obtain a reference cardiac image of multiple phases.
[0066] Exemplarily, after obtaining the heart images to be merged of the receiving channels of the M coils in multiple phases, the heart images to be merged acquired by the multiple receiving channels in the same phase can be merged to obtain a fused heart image of the phase, and then the fused heart image of the phase is filtered to obtain a reference heart image of the phase. The filtering process can include low-pass filtering.
[0067] For example, for the heart image {R 1_1 , R 1_2 , ..., R 1_M} are merged to obtain a fused cardiac image of phase 1, and the fused cardiac image of phase 1 is filtered to obtain a reference cardiac image of phase 1.
[0068] In this embodiment, the cardiac images to be merged acquired by multiple receiving channels in the same phase are merged and then filtered to reduce the interference of noise and improve the accuracy of cardiac movie imaging.
[0069] In one embodiment, before obtaining the multi-phase cardiac image to be merged corresponding to multiple channels according to the first flip angle, the method provided by the present application also includes: obtaining the ease of the longitudinal magnetization of the protons recovering to a steady state after being acted on at different flip angles; determining the first flip angle according to the ease; the higher the ease, the greater the probability of being selected as the first flip angle.
[0070] This embodiment mainly determines the first flip angle. Specifically, the time required for the longitudinal magnetization of the proton to recover to the steady state after the action of different flip angles can be analyzed. Based on the length of time required for the longitudinal magnetization of the proton to recover to the steady state after the action of different flip angles, the ease of the longitudinal magnetization of the proton to recover to the steady state after the action of different flip angles can be obtained; the longer the required time, the lower the ease of the longitudinal magnetization of the proton to recover to the steady state after the action of the flip angle, and the shorter the required time, the higher the ease of the longitudinal magnetization of the proton to recover to the steady state after the action of the flip angle. Then, according to the ease corresponding to each flip angle, the flip angle as the first flip angle is determined among multiple flip angles. The higher the ease corresponding to the flip angle, the greater the probability of being selected as the first flip angle.
[0071] In one embodiment, a multi-phase cardiac image to be homogenized is obtained according to the second flip angle, comprising: after acquiring magnetic resonance data based on the first flip angle, performing an empty scan based on the second flip angle; acquiring magnetic resonance data after the duration of the empty scan is at least one cardiac cycle; and reconstructing the acquired data to obtain a multi-phase cardiac image to be homogenized.
[0072] The first flip angle is a small flip angle, so the imaging based on the first flip angle can be called small flip angle imaging. In order to improve the imaging efficiency, the small flip angle imaging does not need to be performed for multiple cardiac cycles. For example, refer to Figure 3 , two adjacent R waves are regarded as a cardiac cycle. In this sequence, small flip angle imaging is performed for one cardiac cycle. After applying the excitation pulse of the first flip angle to collect magnetic resonance data in the first cardiac cycle, the excitation pulse of the second flip angle is applied to perform an empty scan in the second cardiac cycle. The empty scan means that magnetic resonance data is not collected, that is, the coil is not turned on. In the third cardiac cycle, the excitation pulse of the second flip angle is applied to collect magnetic resonance data, thereby obtaining a multi-phase cardiac image to be homogenized.
[0073] The empty scan based on the second flip angle may continue for multiple cardiac cycles, for example, the empty scan may continue in the third cardiac cycle.
[0074] The sequence may include Figure 4 The Tagging sequence shown is compared with Figure 3For the sequence shown, a tagging module is added before each cardiac cycle. The tagging sequence can be a stripe tagging sequence or a grid tagging sequence. The image obtained by the stripe tagging sequence is as follows: Figure 5 As shown, the grid-shaped Tagging sequence obtains the image, such as Figure 6 shown.
[0075] In this embodiment, before collecting magnetic resonance data based on the second flip angle, at least one cardiac cycle is first scanned empty to reduce the influence of small flip angle imaging on large flip angle imaging.
[0076] In one embodiment, step S204 performs homogenization processing on the cardiac image to be homogenized based on the reference cardiac image of the same phase to obtain a target cardiac image of multiple phases, including: based on the reference cardiac image of the same phase, eliminating the non-uniform signal caused by the near-coil effect in the cardiac image to be homogenized; and obtaining the target cardiac image of multiple phases according to the cardiac image to be homogenized after the elimination of each phase.
[0077] After obtaining a multi-phase reference cardiac image {R1, R2, ..., R i} and the cardiac image to be homogenized {I1, I2, ..., I i}, you can use R i to I i Perform homogenization and remove I i The non-uniform signal caused by the near-coil effect is removed. i It mainly contains contrast signals reflecting the difference in T1 values. i Target heart image UI as phase i i .
[0078] Furthermore, based on the reference cardiac image of the same phase, the non-uniform signal caused by the proximity coil effect in the cardiac image to be homogenized is eliminated, including: dividing the cardiac image to be homogenized in the same phase by the reference cardiac image to eliminate the non-uniform signal caused by the proximity coil effect in the cardiac image to be homogenized.
[0079] For example, I i Divide by R i , to eliminate I i The non-uniform signal is caused by the near-coil effect.
[0080] In one embodiment, step S201 obtains the multi-phase cardiac image to be merged corresponding to the multi-channel according to the first flip angle, including: acquiring magnetic resonance data of at least one cardiac cycle based on the first flip angle; and reconstructing the acquired data to obtain the multi-phase cardiac image to be merged corresponding to the multi-channel.
[0081] Exemplarily, after ECG triggering, an excitation pulse with a first flip angle can be applied, and in phase 1, multiple coils are turned on for magnetic resonance data acquisition to obtain the K-space data line of the receiving channel of each coil in phase 1, and based on the K-space data line of the receiving channel of each coil in phase 1, the heart image to be merged of the receiving channel of each coil in phase 1 can be obtained; in phase 2, multiple coils are turned on for magnetic resonance data acquisition to obtain the K-space data line of the receiving channel of each coil in phase 2, and based on the K-space data line of the receiving channel of each coil in phase 2, the heart image to be merged of the receiving channel of each coil in phase 2 can be obtained. According to the above method, the heart image to be merged of the receiving channel of each coil in each phase can be obtained.
[0082] The contrast of T1 values in images obtained at small flip angles, and the contrast of T1 values in images obtained at large flip angles, such as Figure 7 As shown, the image below the flip angle of 2 is the image obtained by a small flip angle, and the image below the flip angle of 10 is the image obtained by a large flip angle.
[0083] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.
[0084] In one embodiment, Figure 8 As shown, a device for acquiring a multi-phase cardiac image is provided, comprising:
[0085] A first image acquisition module 801 is used to obtain a cardiac image to be merged of multiple phases corresponding to multiple channels according to a first flip angle;
[0086] A reference image acquisition module 802 is used to perform channel merging on the cardiac images to be merged in the same phase to obtain reference cardiac images in multiple phases;
[0087] A second image acquisition module 803, configured to obtain a multi-phase cardiac image to be homogenized according to a second flip angle; the second flip angle is greater than the first flip angle;
[0088] The homogenization processing module 804 is used to perform homogenization processing on the cardiac image to be homogenized based on the reference cardiac image of the same phase to obtain a target cardiac image of multiple phases.
[0089] In one embodiment, the reference image acquisition module 802 is further used to perform channel merging on the cardiac images to be merged in the same phase to obtain a fused cardiac image of multiple phases; and perform filtering on the fused cardiac images of multiple phases to obtain a reference cardiac image of multiple phases.
[0090] In one embodiment, the device provided in the present application also includes: a flip angle determination module, which is used to obtain the ease of the longitudinal magnetization of the proton to recover to a steady state after being subjected to different flip angles; based on the ease, the first flip angle is determined; the higher the ease, the greater the probability of being selected as the first flip angle.
[0091] In one embodiment, the second image acquisition module 803 is further used to perform an empty scan based on the second flip angle after performing magnetic resonance data acquisition based on the first flip angle; perform magnetic resonance data acquisition after the duration of the empty scan is at least one cardiac cycle; and reconstruct the acquired data to obtain a multi-phase cardiac image to be homogenized.
[0092] In one embodiment, the homogenization processing module 804 is further used to eliminate the non-homogeneous signal caused by the near-coil effect in the cardiac image to be homogenized based on the reference cardiac image of the same phase; and obtain the target cardiac image of multiple phases according to the cardiac image to be homogenized after the elimination of each phase.
[0093] In one embodiment, the homogenization processing module 804 is further configured to divide the cardiac image to be homogenized in the same phase by the reference cardiac image to eliminate the non-homogeneous signal caused by the near-coil effect in the cardiac image to be homogenized.
[0094] In one embodiment, the first image acquisition module 801 is further used to acquire magnetic resonance data of at least one cardiac cycle based on the first flip angle; and reconstruct the acquired data to obtain a cardiac image to be merged corresponding to multiple channels and multiple phases.
[0095] The specific definition of the device for acquiring multi-phase cardiac images can be found in the definition of the method for acquiring multi-phase cardiac images in the above text, and will not be repeated here. Each module in the above-mentioned device for acquiring multi-phase cardiac images can be implemented in whole or in part by software, hardware, and a combination thereof. Each of the above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory in the computer device in the form of software, so that the processor can call and execute the operations corresponding to each of the above modules.
[0096] In one embodiment, a computer device is provided, whose internal structure diagram can be as follows: Fig. 9 As shown. The computer device includes a processor, a memory and a network interface connected through a system bus. Among them, the processor of the computer device is used 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, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store the acquisition data of multi-phase cardiac images. The network interface of the computer device is used to communicate with an external terminal through a network connection. The computer device also includes an input and output interface, which is a connection circuit for exchanging information between the processor and the external device. They are connected to the processor through a bus, referred to as an I / O interface. When the computer program is executed by the processor, a method for acquiring multi-phase cardiac images is implemented.
[0097] Those skilled in the art will understand that Fig. 9 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.
[0098] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps in the above-mentioned various method embodiments when executing the computer program.
[0099] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.
[0100] In one embodiment, a computer program product is provided, on which a computer program is stored, and the computer program is used by a processor to execute the steps in the above-mentioned various method embodiments.
[0101] Those of ordinary skill 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, and the above-mentioned computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this 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, etc. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).
[0102] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0103] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.
Claims
1. A method for acquiring a multi-phase cardiac image, characterized in that: The method comprises: According to the first flip angle, a cardiac image to be merged of multiple phases corresponding to multiple channels is obtained; Performing channel merging on the cardiac images to be merged in the same phase to obtain reference cardiac images in multiple phases; According to a second flip angle, a multi-phase cardiac image to be homogenized is obtained; the second flip angle is greater than the first flip angle; The cardiac image to be homogenized is homogenized based on the reference cardiac image of the same phase to obtain a target cardiac image of multiple phases.
2. The method according to claim 1, characterized in that The step of performing channel merging on the cardiac images to be merged in the same phase to obtain reference cardiac images in multiple phases includes: Merging channels of the cardiac images to be merged in the same phase to obtain a fused cardiac image of multiple phases; The multi-phase fused cardiac image is filtered to obtain a multi-phase reference cardiac image.
3. The method according to claim 1, characterized in that Before obtaining the multi-phase cardiac images to be merged corresponding to the multi-channels according to the first flip angle, the method further includes: Obtain the ease with which the longitudinal magnetization of protons recovers to a steady state after being acted upon at different flip angles; The first flip angle is determined according to the ease; the higher the ease, the greater the probability of being selected as the first flip angle.
4. The method according to claim 1, characterized in that The step of obtaining a multi-phase cardiac image to be homogenized according to the second flip angle includes: After acquiring magnetic resonance data based on the first flip angle, performing an empty scan based on the second flip angle; When the duration of the empty scan is at least one cardiac cycle, magnetic resonance data acquisition is performed; The collected data are reconstructed to obtain a multi-phase cardiac image to be homogenized.
5. The method according to claim 1, characterized in that The step of performing a homogenization process on the cardiac image to be homogenized based on the reference cardiac image of the same phase to obtain a target cardiac image of multiple phases includes: Based on the reference cardiac image of the same phase, eliminating the non-uniform signal caused by the near-coil effect in the cardiac image to be homogenized; A target cardiac image with multiple phases is obtained according to the cardiac image to be homogenized after each phase is eliminated.
6. The method according to claim 5, characterized in that The step of removing the non-uniform signal caused by the near-coil effect in the cardiac image to be homogenized based on the reference cardiac image in the same phase includes: The cardiac image to be homogenized in the same phase is divided by the reference cardiac image to eliminate the non-homogeneous signal caused by the near-coil effect in the cardiac image to be homogenized.
7. The method according to claim 1, characterized in that The step of obtaining the cardiac images to be merged of multiple phases corresponding to multiple channels according to the first flip angle includes: Acquiring magnetic resonance data of at least one cardiac cycle based on the first flip angle; The collected data are reconstructed to obtain a multi-phase cardiac image to be merged corresponding to multiple channels.
8. A device for acquiring multi-phase cardiac images, characterized in that: The device comprises: A first image acquisition module, used for obtaining a cardiac image to be merged of multiple phases corresponding to multiple channels according to a first flip angle; A reference image acquisition module, used for performing channel merging on the cardiac images to be merged in the same phase to obtain reference cardiac images in multiple phases; A second image acquisition module, used for obtaining a multi-phase cardiac image to be homogenized according to a second flip angle; the second flip angle is greater than the first flip angle; The homogenization processing module is used to perform homogenization processing on the cardiac image to be homogenized based on the reference cardiac image of the same phase to obtain a target cardiac image of multiple phases.
9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.