Magnetic resonance perfusion imaging method, device, computer equipment and readable storage medium

Abstract

The present application discloses a magnetic resonance perfusion imaging method, device, computer equipment and readable storage medium, which relates to the field of medical imaging technology. In combination with heartbeat movement, continuous marker images and reference images are collected using marker and imaging technology, so that the generated perfusion signal reaches a steady state, and the limitation of heartbeat time is removed, the operation difficulty is reduced, the scanning time is shortened, and the imaging efficiency and imaging quality are improved. The method includes: in response to an image acquisition instruction, determining a target area of ​​the heart to be imaged; in multiple consecutive heartbeat cycles, image acquisition is performed on the target area to obtain a preset number of marker images and a preset number of reference images; based on the preset number of marker images and the preset number of reference images, a perfusion weighted image of the target area is generated.

Description

Technical Field

[0001] The present application relates to the field of medical imaging technology, and in particular to a magnetic resonance perfusion imaging method, apparatus, computer equipment and readable storage medium. Background Art

[0002] Magnetic resonance imaging (MRI) is one of the main imaging methods in modern medical imaging. Its basic principle is to use the magnetic resonance phenomenon, use radio frequency excitation to excite hydrogen protons in the human body, use gradient fields for position encoding, then use receiving coils to receive signals with position information, and finally reconstruct image information through Fourier transform. Magnetic resonance imaging has been widely used in medical imaging, especially perfusion imaging, which has played a huge role in the identification and diagnosis of stroke.

[0003] Arterial spin labeling technology has achieved remarkable results in brain perfusion imaging, but for moving tissues, such as the heart, perfusion imaging based on arterial spin labeling technology still faces great challenges due to tissue movement. Summary of the invention

[0004] In view of this, the present application provides a magnetic resonance perfusion imaging method, apparatus, computer equipment and readable storage medium, the main purpose of which is to solve the current problems of long scanning time, low imaging efficiency and low imaging quality.

[0005] According to a first aspect of the present application, a magnetic resonance perfusion imaging method is provided, the method comprising:

[0006] In response to the image acquisition instruction, determining a target area of ​​the heart for image acquisition;

[0007] In a plurality of consecutive heartbeat cycles, the target area is imaged to obtain a preset number of marked images and a preset number of reference images, wherein the marked images are obtained by image acquisition after the blood flow is signaled, and the reference images are acquired without signaling the blood flow;

[0008] A perfusion weighted image of the target area is generated based on the preset number of marker images and the preset number of reference images.

[0009] Optionally, the preset number of marked images are obtained by collecting images after signal marking of blood flow in multiple consecutive heartbeat cycles, and the preset number of reference images are obtained by collecting images without signal marking of blood flow in multiple consecutive heartbeat cycles; or,

[0010] The marker images and the reference images are collected alternately in a plurality of consecutive heartbeat cycles until the number of the marker images and the number of the reference images collected reach the preset number.

[0011] Optionally, the signal marking of blood flow comprises:

[0012] A double focusing mode or a single focusing mode is adopted to apply an inversion and / or saturation pulse signal to the blood flow in the target area to label the blood spin.

[0013] Optionally, the collecting an image of the target area includes:

[0014] Determining a preset imaging sequence, wherein the preset imaging sequence includes one of a balanced steady-state free precession sequence or a gradient echo sequence;

[0015] The target area is imaged using the preset imaging sequence, and the imaging result is output.

[0016] Optionally, generating the perfusion weighted image of the target area based on the preset number of marked images and the preset number of reference images includes:

[0017] Using an average algorithm to improve the signal-to-noise ratio of the preset number of labeled images to obtain a first output image, and counting the magnetization vectors of protons on the first output image to obtain a first signal intensity of the first output image;

[0018] Using an averaging algorithm to improve the signal-to-noise ratio of the preset number of reference images to obtain a second output image, and counting the magnetization vectors of protons on the second output image to obtain a second signal intensity of the second output image;

[0019] The signal intensity difference is generated based on a difference between the first signal intensity and the second signal intensity, and the perfusion weighted image is generated using the signal intensity difference.

[0020] Optionally, generating the perfusion weighted image of the target area based on the preset number of marked images and the preset number of reference images includes:

[0021] Based on the preset number of marked images and the preset number of reference images, determining the preset number of image groups, each image group in the preset number of image groups includes a marked image and a reference image;

[0022] Based on the intensity difference between the signal intensities of a marked image and a reference image included in the preset number of image groups, obtaining the preset number of intensity difference values;

[0023] Based on the intensity difference, performing perfusion imaging using a hemodynamic model to obtain the preset number of regional perfusion images;

[0024] Based on the preset number of regional perfusion images, a perfusion weighted image of the target region is generated.

[0025] Optionally, after determining the target area for image acquisition in response to the image acquisition instruction, the method further includes:

[0026] Acquire respiratory gating signal;

[0027] Based on the respiratory gating signal, obtaining a respiratory stable period;

[0028] The step of acquiring images of the target area during a plurality of consecutive heartbeat cycles includes:

[0029] During the respiratory stable period, images of the target area are collected in a plurality of consecutive heartbeat cycles.

[0030] According to a second aspect of the present application, a magnetic resonance perfusion imaging device is provided, the device comprising:

[0031] a determination module, configured to determine, in response to the image acquisition instruction, a target area of ​​the heart for image acquisition;

[0032] An acquisition module, used for acquiring images of the target area in a plurality of consecutive heartbeat cycles to obtain a preset number of marked images and a preset number of reference images, wherein the marked images are acquired after the blood flow is signal marked, and the reference images are acquired without signal marking the blood flow;

[0033] A generating module is used to generate a perfusion weighted image of the target area based on the preset number of marked images and the preset number of reference images.

[0034] Optionally, the preset number of marked images are obtained by capturing images after signal marking of blood flow in multiple consecutive heartbeat cycles, and the preset number of reference images are obtained by capturing images without signal marking of blood flow in multiple consecutive heartbeat cycles; or, the acquisition module is used to alternately capture the marked images and the reference images in multiple consecutive heartbeat cycles until the number of captured marked images and the number of reference images reach the preset number.

[0035] Optionally, the acquisition module is used to apply flipping and / or saturation pulse signals to the blood flow in the target area using a double focusing mode or a single focusing mode, mark the blood spins, enhance the signal strength of the position where the pulse signal hits in the blood, and complete the signal marking of the blood flow.

[0036] Optionally, the acquisition module is used to determine a preset imaging sequence, wherein the preset imaging sequence includes one of a balanced steady-state free precession sequence or a gradient echo sequence; use the preset imaging sequence to image the target area, and output the imaging result.

[0037] Optionally, the generating module is configured to use an averaging algorithm to improve the signal-to-noise ratio of the preset number of labeled images to obtain a first output image, and to count the magnetization vectors of protons on the first output image to obtain a first signal intensity of the first output image; use an averaging algorithm to improve the signal-to-noise ratio of the preset number of reference images to obtain a second output image, and to count the magnetization vectors of protons on the second output image to obtain a second signal intensity of the second output image; generate the signal intensity difference based on the difference between the first signal intensity and the second signal intensity, and generate the perfusion weighted image using the signal intensity difference.

[0038] Optionally, the generation module is used to determine the preset number of image groups based on the preset number of marked images and the preset number of reference images, each of the preset number of image groups including a marked image and a reference image; obtain the preset number of intensity differences based on the intensity difference of the signal intensity of a marked image and a reference image included in the preset number of image groups; perform perfusion imaging using a hemodynamic model based on the intensity difference to obtain the preset number of regional perfusion images; and generate a perfusion weighted image of the target area based on the preset number of regional perfusion images.

[0039] Optionally, the device further comprises:

[0040] An acquisition module, used for acquiring a breathing gating signal;

[0041] The acquisition module is further used to acquire a respiratory stable period based on the respiratory gating signal;

[0042] The acquisition module is further used to acquire images of the target area in a plurality of consecutive heartbeat cycles during the respiratory stable period.

[0043] According to a third aspect of the present application, a computer device is provided, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of any one of the methods described in the first aspect when executing the computer program.

[0044] According to a fourth aspect of the present application, a readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of any one of the methods described in the first aspect are implemented.

[0045] By means of the above technical scheme, the present application provides a magnetic resonance perfusion imaging method, apparatus, computer equipment and readable storage medium. The present application responds to an image acquisition instruction, determines a target area of ​​the heart to be imaged, acquires images of the target area in multiple consecutive heartbeat cycles, obtains a preset number of marked images and a preset number of reference images, and generates a perfusion weighted image of the target area based on the preset number of marked images and the preset number of reference images. In combination with heartbeat movement, continuous marked images and reference images are acquired in continuous heartbeat cycles using marking and imaging technology. Not only does the generated perfusion signal reach a steady state based on the signal strength difference between the continuous marked images and the reference images, but also the limitation of the heartbeat time is removed, the operation difficulty is reduced, the scanning time is shortened, and the efficiency and imaging quality of magnetic resonance perfusion imaging are improved.

[0046] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0048] Figure 1 A schematic diagram of a magnetic resonance perfusion imaging method provided in an embodiment of the present application is shown;

[0049] Figure 2A A schematic diagram of another magnetic resonance perfusion imaging method provided in an embodiment of the present application is shown;

[0050] Figure 2B A schematic diagram of a marking method provided in an embodiment of the present application is shown;

[0051] Figure 2CA schematic diagram of an imaging timing provided by an embodiment of the present application is shown;

[0052] Figure 3 A schematic structural diagram of a magnetic resonance perfusion imaging device provided in an embodiment of the present application is shown;

[0053] Figure 4 A schematic diagram of the device structure of a computer device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0054] The exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0055] The present application embodiment provides a magnetic resonance perfusion imaging method, such as Figure 1 As shown, the method includes:

[0056] 101. In response to an image acquisition instruction, determine a target area of ​​the heart for image acquisition.

[0057] The present application is applied in a magnetic resonance system and can be used for perfusion imaging of the heart. An image acquisition portal is provided at the front end of the magnetic resonance system. When magnetic resonance imaging of a patient is required, the doctor can trigger the image acquisition portal to set which part of the perfusion image he wants to acquire in the magnetic resonance system, and issue an image acquisition instruction to the magnetic resonance system. In this way, in response to the image acquisition instruction, the magnetic resonance system will use the area to be imaged set by the doctor as the target area, so as to subsequently generate a perfusion-weighted image of the target area. It should be noted that the target area can also be called a region of interest, and the target area can be the entire heart or a partial area of ​​the heart.

[0058] Among them, the image acquisition instruction can be issued manually by the doctor, or it can automatically determine that the image acquisition instruction has been received when the magnetic resonance system detects that the target area has been entered into the acquisition box. The method of issuing the image acquisition instruction in this application is not specifically limited.

[0059] 102. In a plurality of consecutive heartbeat cycles, collect images of the target area to obtain a preset number of marked images and a preset number of reference images.

[0060] At present, in order to obtain myocardial perfusion images, first-pass contrast agent magnetic resonance perfusion imaging technology is generally used in clinical practice. It mainly uses a large dose of gadolinium contrast agent to complete the rapid acquisition of multiple dynamics of the heart in a short time, observe the changes in the signal intensity of the myocardium when the contrast agent passes for the first time, and analyze the relevant perfusion parameters. Myocardial magnetic resonance perfusion imaging usually uses ECG gating triggering, uses saturation (saturation) or inversion (inversion) as a pre-preparation module, and uses bssfp (balance SSFP, balanced steady-state free precession sequence) or gre (gradient echo sequence) to acquire dynamic perfusion images. Non-invasive magnetic resonance perfusion imaging based on arterial spin labeling generally uses spatial selective labeling technology, applies an adiabatic inversion pulse upstream of myocardial perfusion, labels in one heartbeat, waits for a period of time for the marked blood flow to flow into the plane of interest, and collects the marked image in this heartbeat or the next heartbeat. Similarly, the marking module without applying a mark or mirroring on the imaging surface is used for image acquisition to obtain a reference image, and the marked image and the reference image are compared to obtain a perfusion weighted image through the difference between the two images.

[0061] However, the inventors of the present application recognize that both of the above imaging methods have certain drawbacks. The first-pass contrast agent magnetic resonance perfusion imaging technology currently used in clinical practice requires the injection of exogenous contrast agents, which have toxic effects. Other magnetic resonance perfusion imaging technologies based on arterial spin labeling have the following disadvantages: first, the scanning time is long and the efficiency is low; second, the scanning operation requirements are high and the positioning needs to be very accurate. It is difficult to avoid the contamination of the blood flow in other locations by the labeling module; third, due to the time limit of the heartbeat, the conventional labeling module is relatively sensitive to the arterial transfer time and the delay time after labeling.

[0062] Therefore, the embodiment of the present application proposes a magnetic resonance perfusion imaging method, which combines ECG gating and flow rate selective arterial spin labeling to perform magnetic resonance perfusion imaging, reduce the requirements for scanning operations, and obtain fast myocardial magnetic resonance perfusion imaging. Magnetic resonance perfusion imaging combines heartbeat movement, and in multiple consecutive heartbeat cycles, the target area is imaged to obtain a preset number of marked images and a preset number of reference images. Among them, the preset number of marked images are obtained by image acquisition after the blood flow is signaled in multiple consecutive heartbeat cycles, and the preset number of reference images are obtained by image acquisition in multiple consecutive heartbeat cycles without signaling the blood flow. When image acquisition is performed in this way, the process of image acquisition of the target area is divided into two parts. In each heartbeat cycle of the first part, the blood flow upstream of the target area will be signaled and imaged when the blood flow flows into the target area, so as to obtain a marked image; in each heartbeat cycle of the second part, a reference image will be acquired, and the reference image does not need to signal the blood flow upstream of the target area, and is directly acquired, that is, the reference image is acquired without signaling the blood flow. Specifically, the signal marking of the blood flow upstream of the target area can be achieved by applying a flow rate selective arterial spin labeling method. The preset number is determined by the number of consecutive heartbeat cycles collected in one breath holding. For example, taking 20 heartbeats collected in one breath holding as an example, 10 consecutive marked images and 10 consecutive reference images can be obtained, and the preset number is 10. In the embodiment of the present application, the blood flow upstream of the target area is determined according to the flow direction of the blood flow. The blood flow flows into the target area from one side and then flows out of the target area from one side. The blood flow above the inflow side can be called the blood flow upstream of the target area. The marking position of the blood flow upstream of the target area can be set according to actual needs and is not limited here.

[0063] It should be noted that, in the actual application process, the acquisition of a preset number of marked images and a preset number of reference images can also be performed in an alternating acquisition manner, that is, the acquisition of marked images and reference images is performed alternately in multiple consecutive heartbeat cycles until the number of marked images and the number of reference images collected reach a preset number. For example, in a certain heartbeat cycle, the blood flow upstream of the target area is marked and a marked image is collected, and then in the next heartbeat cycle, the blood flow is not marked, and a reference image is directly collected. When entering a new heartbeat cycle, the blood flow is re-marked and a marked image is collected until the number of marked images and the number of reference images collected reach a preset number. By adopting an alternating acquisition method, the acquired marked images and reference images are evenly distributed in the time dimension, which is conducive to further suppressing the influence of irregular heart movement. The embodiment of the present application does not specifically limit the method of collecting a preset number of marked images and reference images.

[0064] 103. Generate a perfusion weighted image of the target area based on a preset number of marked images and a preset number of reference images.

[0065] In the embodiment of the present application, after obtaining a preset number of continuous marked images and reference images, since the signal marking of blood flow is actually a reversal of the proton magnetic moment, the magnetization vector of the proton is reduced, and thus the signal intensity during imaging is reduced. Therefore, based on the signal intensity difference between the preset number of marked images and the preset number of reference images, a perfusion-weighted image of the target area can be generated, so as to facilitate the subsequent further use of the perfusion-weighted image to generate myocardial blood perfusion images, examination reports, and the like.

[0066] The method provided in the embodiment of the present application determines, in response to an image acquisition instruction, a target area of ​​the heart for image acquisition, acquires images of the target area in multiple consecutive heartbeat cycles to obtain a preset number of marked images and a preset number of reference images, and generates a perfusion-weighted image of the target area based on the preset number of marked images and the preset number of reference images, and acquires consecutive marked images and reference images in consecutive heartbeat cycles using marking and imaging technology in combination with heartbeat movement, which not only enables the generated perfusion signal to reach a steady state based on the signal strength difference between the consecutive marked images and the reference images, but also removes the limitation of the heartbeat time, reduces the difficulty of operation, shortens the scanning time, and improves the efficiency and imaging quality of magnetic resonance perfusion imaging.

[0067] The present application embodiment provides a magnetic resonance perfusion imaging method, such as Figure 2A As shown, the method includes:

[0068] 201. In response to an image acquisition instruction, determine a target area of ​​the heart for image acquisition.

[0069] In an embodiment of the present application, the method can be applied to a magnetic resonance system, which utilizes the magnetic resonance phenomenon, uses radio frequency excitation to excite hydrogen protons in the human body, uses a gradient field for position encoding, and then uses a receiving coil to receive a signal with position information, and finally reconstructs the image information through Fourier transform. When the magnetic resonance system receives an image acquisition instruction, it indicates that an image acquisition of the patient's heart is currently required, so in response to the image acquisition instruction, the magnetic resonance system determines the target area of ​​the heart to be imaged. The target area can be manually selected or recognized by the magnetic resonance system itself, and the present application does not specifically limit this.

[0070] 202. Use ECG gating or peripheral pulse gating to identify heartbeats, and when heartbeat motion is identified based on ECG gating or peripheral pulse gating, start imaging scanning of the target area.

[0071] In an embodiment of the present application, magnetic resonance perfusion imaging can be used to perform magnetic resonance perfusion imaging of the heart. Cardiac magnetic resonance perfusion imaging needs to be combined with the patient's heartbeat movement. Therefore, the magnetic resonance system will use ECG gating or peripheral pulse gating to identify the heartbeat, and when the heartbeat movement is identified based on ECG gating or peripheral pulse gating, the sequence execution is triggered to start imaging scanning of the target area, thereby realizing tissue motion monitoring based on gating technology and acquiring images during the motion freezing period.

[0072] It should be noted that, in another optional implementation, since the patient needs to hold his breath during the magnetic resonance process, the embodiment of the present application can also be combined with the recognition of breathing to trigger imaging acquisition during the stable period of the patient's breathing, reduce the difficulty of breath holding, increase the average number of times, and obtain a higher signal-to-noise ratio. Specifically, a respiratory gating signal can be obtained, and based on the respiratory gating signal, the respiratory stable period is obtained. During the respiratory stable period, the target area is imaged in multiple consecutive heartbeat cycles. The embodiment of the present application does not specifically limit whether to perform the respiratory recognition operation.

[0073] 203. In a plurality of consecutive heartbeat cycles, determine a preset imaging sequence, use the preset imaging sequence to image the target area, and output the imaging result to obtain a preset number of marked images and a preset number of reference images.

[0074] In an embodiment of the present application, the magnetic resonance system continuously performs imaging acquisition in multiple consecutive heartbeat cycles, applies imaging operations to the target area, determines a preset imaging sequence, uses the preset imaging sequence to image the target area, and outputs the imaging results to obtain a preset number of labeled images and a preset number of reference images. The preset imaging sequence includes one of a balanced steady-state free precession sequence (bSSFP) or a gradient echo sequence (GRE), that is, after applying the imaging module to the target area, the bSSFP or GRE is used to read out and obtain the imaging result.

[0075] Further, in the embodiment of the present application, the process of image acquisition is divided into two parts, the first part acquires a preset number of marked images, and the second part acquires a preset number of reference images. Among them, the marked image is obtained by image acquisition of the target area after signal marking. In the first part, the blood flow upstream of the target area is signal marked in each heartbeat cycle and imaged when the marked blood flow enters the target area, thereby obtaining a marked image. In an optional implementation scheme, the specific acquisition process is as follows: in the first heartbeat cycle after the heartbeat movement occurs, the blood flow upstream of the target area is signal marked, and image acquisition is performed when the marked blood flow enters the target area to obtain a marked image. Subsequently, when it is identified that the next heartbeat cycle entering the first heartbeat cycle is entered, the acquisition method of the first cycle is used to obtain a marked image, until the number of the collected marked images reaches the preset number, and the preset number of marked images is obtained. It should be noted that the preset number can be set by itself, such as 5, 10, 15, etc., or it can also be determined by the number of consecutive heartbeat cycles collected in one breath holding, and this application does not specifically limit this. Furthermore, the signal marking of the target area can be achieved by using a velocity-selective marking module to mark the endogenous tracer, and a velocity-selective arterial spin label is applied in each heartbeat cycle of the first part. The specific marking mode can be a single convergence or double convergence mode, that is, a double convergence mode or a single convergence mode is used to apply a flip and / or saturation pulse signal to the blood flow, mark the blood spin, enhance the signal strength of the position where the pulse signal hits in the blood, and complete the signal marking of the blood flow. In an optional embodiment, the double convergence mode is used, and a pulse signal of a first angle is applied to the blood flow upstream of the target area, and after a first preset time, a convergence signal of a second angle is applied to the blood flow upstream of the target area again, and after a second preset time, a convergence signal of a second angle is applied to the blood flow upstream of the target area again, and after a third preset time, a pulse signal of a third angle is finally applied to the blood flow upstream of the target area to complete the signal marking of the blood flow upstream of the target area. Specifically, the first angle can be 90 degrees, the second angle can be 180 degrees, and the third angle can be -90 degrees. Figure 2B As shown in FIG. 1 , a double-regression pattern of (90)-(180)-(180)-(-90) is used for labeling, and the signal is as follows: Figure 2BAs shown in the marked image. In another optional implementation scheme, a single refocusing mode is used, and a pulse signal of a fourth angle needs to be applied to the blood flow upstream of the target area, and after a fourth preset time, a refocusing signal of a fifth angle is applied to the blood flow upstream of the target area again, and after a fifth preset time, a refocusing signal of a sixth angle is applied to the blood flow upstream of the target area to complete the marking of the blood flow signal upstream of the target area. Specifically, the fourth angle can be 90 degrees, the fifth angle can be 180 degrees, and the sixth angle is -90 degrees. In this way, the radio frequency pulse signal first sends out a 90-degree excitation pulse signal, and then, after a period of time, a 180-degree refocusing signal is sent out, and after a period of time, a -90-degree pulse signal is finally sent out. Image acquisition is performed after the marked blood flow flows into the target area.

[0076] The reference image is collected in the second part. When collecting the reference image, no signal marking is required in each heartbeat cycle. Only the imaging module is applied. BSSFP or GRE can also be used to read out to obtain a preset number of reference images. The specific collection process is as follows: when it is recognized that a new heartbeat cycle has entered, the target area is imaged to obtain a reference image, and when it is recognized that the next heartbeat cycle of the new heartbeat cycle has entered, the target area is imaged again to obtain a reference image, until the number of reference images collected reaches a preset number, and a preset number of reference images are obtained. Among them, the new heartbeat cycle can be identified after the collection of the preset number of marked images is completed, and the collection of reference images can be started when the new heartbeat cycle is recognized, and the preset number can be consistent with the preset number corresponding to the above-mentioned marked image. In addition, as described in the above step 102, the collection of the preset number of marked images and the preset number of reference images can also be carried out by alternating collection, which will not be repeated here.

[0077] It should be noted that both the marked image and the reference image can be acquired at any position of the cardiac cycle, such as during the cardiac rest period, and this application does not specifically limit this. Figure 2C As shown in the imaging timing diagram, in the first two cardiac cycles, flow-selective arterial spin labeling is applied once during the cardiac rest period of each cardiac cycle, and labeled images are collected to obtain two labeled images; in the next two cardiac cycles, reference images are collected during the cardiac rest period of each cardiac cycle to obtain two reference images.

[0078] 204. Determine a signal strength difference based on a preset number of marked images and a preset number of reference images.

[0079] In the embodiment of the present application, after the continuous quantitative labeled image and the reference image are acquired, the perfusion weighted image can be subsequently obtained by the signal intensity difference between the labeled image and the reference image. Therefore, it is necessary to perform statistics on the signal intensity difference based on the continuous quantitative labeled image and the reference image. The process of statistically calculating the signal intensity difference is as follows:

[0080] First, an averaging algorithm is used to improve the signal-to-noise ratio of a preset number of labeled images to obtain a first output image, and the magnetization vectors of protons on the first output image are counted to obtain a first signal intensity of the first output image. Subsequently, an averaging algorithm is used to improve the signal-to-noise ratio of a preset number of reference images to obtain a second output image, and the magnetization vectors of protons on the second output image are counted to obtain a second signal intensity of the second output image. Finally, based on the difference between the first signal intensity and the second signal intensity, a signal intensity difference is generated. Specifically, variance calculation can be performed based on the averaging algorithm to reduce image noise and improve the signal-to-noise ratio. In this way, by processing multiple consecutive labeled images and reference images in the above manner, the signal intensity difference of the final output can be balanced, and multiple acquisitions can be used to ensure the stability of the signal intensity difference, thereby achieving a steady state of the perfusion signal and improving the imaging quality.

[0081] In another optional embodiment, since multiple continuous marker images and reference images are acquired, a quantitative regional perfusion image can be generated after a preset number of marker images and a preset number of reference images are acquired. Specifically, a preset number of image groups can be determined based on the preset number of marker images and the preset number of reference images, wherein each image group in the preset number of image groups includes a marker image and a reference image, and based on the intensity difference of the signal intensity of a marker image and a reference image included in the preset number of image groups, a preset number of intensity differences are obtained. In an optional embodiment, the process of generating a quantitative regional perfusion image is as follows: first, any marker image is selected as the first marker image from the preset number of marker images, and any reference image at the same spatial position is selected as the first reference image from the preset number of reference images, and the two images are used to form an image group. Subsequently, the magnetization vector of the proton on the first marker image is counted to obtain the third signal intensity of the first marker image, and the magnetization vector of the proton on the first reference image is counted to obtain the fourth signal intensity of the first reference image, and the intensity difference between the fourth signal intensity and the third signal intensity is calculated as the intensity difference of the image group. In this way, any other marked image other than the first marked image is selected from the preset number of marked images as the second marked image, and any other reference image at the same spatial position other than the first reference image is selected from the preset number of reference images as the second reference image to form a new image group, and the intensity difference between the signal intensity of the second reference image and the signal intensity of the second marked image is calculated in the newly formed image group, until the preset number of marked images and the preset number of reference images are traversed to obtain the preset number of intensity differences. Then, the following processing is performed on each of the preset number of intensity differences: according to the intensity difference, perfusion imaging is performed using the hemodynamic model to obtain the regional perfusion image of the target area. In this way, the preset number of regional perfusion images corresponding to the preset number of intensity differences can be obtained, and the preset number of regional perfusion images can be output. Taking the target area as the heart as an example, a preset number of myocardial perfusion images can be obtained.

[0082] 205. Using signal intensity differences, a perfusion-weighted image of the target area is generated.

[0083] In the embodiment of the present application, after the signal intensity difference is generated, the signal intensity difference can be used to generate a perfusion weighted image of the target area.

[0084] The method provided in the embodiment of the present application identifies heartbeat movements, utilizes marking and imaging technology, collects multiple continuous marking images and reference images, makes the signal intensity difference reach a steady state, and then obtains accurate perfusion weighting and images, removes the limitation of heartbeat time, reduces the difficulty of operation, shortens the scanning time, and improves imaging efficiency and imaging quality.

[0085] Further, as Figure 1 For the specific implementation of the method, the present application embodiment provides a magnetic resonance perfusion imaging device, such as Figure 3 As shown, the device includes: a determination module 301, a collection module 302 and a generation module 303.

[0086] The determination module 301 is used to determine a target area of ​​the heart for image acquisition in response to an image acquisition instruction;

[0087] The acquisition module 302 is used to acquire images of the target area in a plurality of consecutive heartbeat cycles to obtain a preset number of marked images and a preset number of reference images, wherein the marked images are acquired after the blood flow is signal marked, and the reference images are acquired without signal marking the blood flow;

[0088] The generating module 303 is used to generate a perfusion weighted image of the target area based on the preset number of marked images and the preset number of reference images.

[0089] In a specific application scenario, the preset number of marked images are obtained by capturing images after signal marking of blood flow in multiple consecutive heartbeat cycles, and the preset number of reference images are obtained by capturing images without signal marking of blood flow in multiple consecutive heartbeat cycles; or, the acquisition module 302 is used to alternately capture the marked images and the reference images in multiple consecutive heartbeat cycles until the number of the captured marked images and the number of the captured reference images reach the preset number.

[0090] In a specific application scenario, the acquisition module 302 is used to adopt a double focusing mode or a single focusing mode to apply a flipping and / or saturation pulse signal to the blood flow in the target area, mark the blood spin, enhance the signal strength of the position where the pulse signal hits in the blood, and complete the signal marking of the blood flow.

[0091] In a specific application scenario, the acquisition module 302 is used to determine a preset imaging sequence, which includes a balanced steady-state free precession sequence or a gradient echo sequence; use the preset imaging sequence to image the target area, and output the imaging result.

[0092] In a specific application scenario, the generation module 303 is used to use an averaging algorithm to improve the signal-to-noise ratio of the preset number of marked images to obtain a first output image, and to count the magnetization vectors of protons on the first output image to obtain a first signal intensity of the first output image; use an averaging algorithm to improve the signal-to-noise ratio of the preset number of reference images to obtain a second output image, and to count the magnetization vectors of protons on the second output image to obtain a second signal intensity of the second output image; based on the difference between the first signal intensity and the second signal intensity, generate the signal intensity difference, and use the signal intensity difference to generate the perfusion weighted image.

[0093] In a specific application scenario, the generation module 303 is used to determine the preset number of image groups based on the preset number of marked images and the preset number of reference images, each of the preset number of image groups including a marked image and a reference image; based on the intensity difference of the signal intensity of a marked image and a reference image included in the preset number of image groups, obtain the preset number of intensity differences; based on the intensity difference, perform perfusion imaging using a hemodynamic model to obtain the preset number of regional perfusion images; based on the preset number of regional perfusion images, generate a perfusion weighted image of the target area.

[0094] In a specific application scenario, the device also includes:

[0095] An acquisition module, used for acquiring a breathing gating signal;

[0096] The acquisition module is further used to acquire the respiratory stable period based on the respiratory gating signal;

[0097] The acquisition module 302 is further configured to acquire images of the target area during a plurality of consecutive heartbeat cycles during the respiratory stable period.

[0098] The device provided in the embodiment of the present application responds to an image acquisition instruction, determines a target area of ​​the heart for image acquisition, acquires images of the target area in multiple consecutive heartbeat cycles, obtains a preset number of marked images and a preset number of reference images, and generates a perfusion-weighted image of the target area based on the preset number of marked images and the preset number of reference images, and uses marking and imaging technology to acquire consecutive marked images and reference images in consecutive heartbeat cycles in combination with heartbeat movement, which not only enables the generated perfusion signal to reach a steady state based on the signal strength difference between the consecutive marked images and the reference images, but also removes the limitation of the heartbeat time, reduces the difficulty of operation, shortens the scanning time, and improves the efficiency and imaging quality of magnetic resonance perfusion imaging.

[0099] It should be noted that for other corresponding descriptions of the functional units involved in the magnetic resonance perfusion imaging device provided in the embodiment of the present application, reference can be made to Figure 1 and Figure 2A The corresponding description in will not be repeated here.

[0100] In an exemplary embodiment, see Figure 4 , and also provides a device, which includes a bus, a processor, a memory and a communication interface, and may also include an input and output interface and a display device, wherein each functional unit can communicate with each other through the bus. The memory stores a computer program, and the processor is used to execute the program stored in the memory and execute the magnetic resonance perfusion imaging method in the above embodiment.

[0101] A readable storage medium stores a computer program, which implements the steps of the magnetic resonance perfusion imaging method when executed by a processor.

[0102] Through the description of the above implementation methods, those skilled in the art can clearly understand that the present application can be implemented by hardware, or by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.), including a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each implementation scenario of the present application.

[0103] Those skilled in the art will appreciate that the accompanying drawings are merely schematic diagrams of a preferred implementation scenario, and the modules or processes in the accompanying drawings are not necessarily required for implementing the present application.

[0104] Those skilled in the art will appreciate that the modules in the device in the implementation scenario can be distributed in the device in the implementation scenario according to the implementation scenario description, or can be changed accordingly and located in one or more devices different from the implementation scenario. The modules in the above implementation scenario can be combined into one module, or can be further split into multiple sub-modules.

[0105] The above application serial numbers are for description only and do not represent the advantages or disadvantages of the implementation scenarios.

[0106] The above disclosure only discloses several specific implementation scenarios of the present application. However, the present application is not limited thereto, and any changes that can be conceived by technicians in this field should fall within the scope of protection of the present application.

Claims

1. A magnetic resonance perfusion imaging method, characterized in that: include: In response to the image acquisition instruction, determining a target area of ​​the heart for image acquisition; In a plurality of consecutive cardiac cycles, the target area is imaged to obtain a preset number of marked images and a preset number of reference images, wherein the marked images are obtained by performing image acquisition after signal marking of the blood flow, and when acquiring the preset number of marked images, in the first cardiac cycle after the cardiac movement occurs, the blood flow upstream of the target area is signal marked, and when the marked blood flow enters the target area, image acquisition is performed to obtain a marked image, and when it is identified that the next cardiac cycle of the first cardiac cycle has been entered, the acquisition method of the first cycle is adopted to obtain a marked image, until the acquired marked images The number of images reaches the preset number, the preset number of marked images is obtained; the reference images are collected without signal marking of blood flow; the preset number of marked images are obtained by collecting images after signal marking of blood flow in multiple consecutive heartbeat cycles, and the preset number of reference images are obtained by collecting images without signal marking of blood flow in multiple consecutive heartbeat cycles; or, the marked images and the reference images are collected alternately in multiple consecutive heartbeat cycles until the number of the collected marked images and the number of the collected reference images reach the preset number; A perfusion weighted image of the target area is generated based on the preset number of marker images and the preset number of reference images.

2. The method according to claim 1, characterized in that: The signal marking of blood flow comprises: A double focusing mode or a single focusing mode is adopted to apply an inversion and / or saturation pulse signal to the blood flow in the target area to label the blood spin.

3. The method according to claim 1, characterized in that: The step of collecting an image of the target area comprises: Determining a preset imaging sequence, wherein the preset imaging sequence includes one of a balanced steady-state free precession sequence or a gradient echo sequence; The target area is imaged using the preset imaging sequence, and the imaging result is output.

4. The method according to claim 1, characterized in that: The step of generating the perfusion weighted image of the target area based on the preset number of marked images and the preset number of reference images includes: Using an average algorithm to improve the signal-to-noise ratio of the preset number of labeled images to obtain a first output image, and counting the magnetization vectors of protons on the first output image to obtain a first signal intensity of the first output image; Using an averaging algorithm to improve the signal-to-noise ratio of the preset number of reference images to obtain a second output image, and counting the magnetization vectors of protons on the second output image to obtain a second signal intensity of the second output image; A signal intensity difference is generated based on a difference between the first signal intensity and the second signal intensity, and the perfusion weighted image is generated using the signal intensity difference.

5. The method according to claim 1, characterized in that The step of generating the perfusion weighted image of the target area based on the preset number of marked images and the preset number of reference images includes: Based on the preset number of marked images and the preset number of reference images, determining the preset number of image groups, each image group in the preset number of image groups includes a marked image and a reference image; Based on the intensity difference between the signal intensities of a marked image and a reference image included in the preset number of image groups, obtaining the preset number of intensity difference values; Based on the intensity difference, performing perfusion imaging using a hemodynamic model to obtain the preset number of regional perfusion images; Based on the preset number of regional perfusion images, a perfusion weighted image of the target region is generated.

6. The method according to claim 1, characterized in that After determining the target area to be imaged in response to the image acquisition instruction, the method further includes: Acquire respiratory gating signal; Based on the respiratory gating signal, obtaining a respiratory stable period; The step of acquiring images of the target area during a plurality of consecutive heartbeat cycles includes: During the respiratory stable period, images of the target area are collected in a plurality of consecutive heartbeat cycles.

7. A magnetic resonance perfusion imaging device, characterized in that: include: a determination module, configured to determine, in response to the image acquisition instruction, a target area of ​​the heart for image acquisition; The acquisition module is used to acquire images of the target area in multiple consecutive heartbeat cycles to obtain a preset number of marked images and a preset number of reference images, wherein the marked images are acquired by acquiring images after signal marking of the blood flow, and when acquiring the preset number of marked images, in the first heartbeat cycle after the heartbeat movement occurs, the blood flow upstream of the target area is signal marked, and when the marked blood flow enters the target area, image acquisition is performed to obtain a marked image, and when it is identified that the next heartbeat cycle of the first heartbeat cycle has been entered, the acquisition method of the first cycle is adopted to obtain a marked image, until the preset number of marked images are acquired. The number of the marked images reaches the preset number, and the preset number of marked images is obtained; the reference images are collected without signal marking the blood flow; the preset number of marked images are obtained by collecting images after signal marking the blood flow in multiple consecutive heartbeat cycles, and the preset number of reference images are obtained by collecting images without signal marking the blood flow in multiple consecutive heartbeat cycles; or, the marked images and the reference images are collected alternately in multiple consecutive heartbeat cycles until the number of the collected marked images and the number of the collected reference images reach the preset number; A generating module is used to generate a perfusion weighted image of the target area based on the preset number of marked images and the preset number of reference images.

8. 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 steps of the method according to any one of claims 1 to 6 are implemented.

9. A readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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