Animal aortic plaque magnetic resonance imaging method and system based on cardiac saturation band

Abstract

An animal aortic plaque magnetic resonance imaging method and system based on a cardiac saturation band, relating to the technical field of magnetic resonance angiography. By means of a magnetic resonance scanner, a scout image of an animal is first acquired to determine a plaque imaging area and the position of a cardiac saturation band; once the cardiac saturation band has been located, respiratory gating is started to trigger collection of data, and by incorporating various magnetic resonance imaging techniques, an animal aortic plaque magnetic resonance imaging result is obtained. A high-resolution and high-contrast animal aortic plaque image can be rapidly acquired, reducing image artifacts. The present invention is suitable for basic and translational research on atherosclerosis model animals, can achieve non-invasive vascular wall structure imaging and composition analysis without applying a contrast agent, and can also implement in-vivo tracking of a new contrast agent and a drug.

Description

Animal aortic plaque magnetic resonance imaging method and system based on cardiac saturation band Technical Field

[0001] The present application relates to the technical field of magnetic resonance angiography, and more specifically to a method and system for magnetic resonance imaging of animal aortic plaques based on a cardiac saturation band. Background Art

[0002] Atherosclerosis (AS) is a globally recognized major public health issue. It can lead to various cardiovascular diseases, including coronary artery disease and stroke, resulting in a significant number of deaths. AS is caused by the accumulation of atherosclerotic plaques on blood vessel walls, leading to arterial narrowing. Thrombosis caused by the rupture of vulnerable plaques is the primary cause of serious adverse events.

[0003] Characteristics of vulnerable plaques include a lipid-rich necrotic core, intraplaque hemorrhage, fibrous cap rupture, local thrombosis, inflammatory response, and increased neovascularization. Currently, vulnerable plaques can be identified using methods such as Doppler ultrasound, CT, and MRI. MRI, with its multi-parameter imaging sequences, can generate multi-contrast images from any angle. Its non-invasive and radiation-free nature allows for large-scale screening and longitudinal monitoring of high-risk populations, making it a primary tool for clinical diagnosis and follow-up.

[0004] The clinical screening, diagnosis and treatment of vulnerable plaques are current research hotspots. Among them, the development of diagnostic contrast agents and therapeutic drugs for preclinical vulnerable plaques is particularly important, which also requires the use of MRI imaging technology to evaluate their effects. However, due to experimental ethical issues such as drug safety and the limitation of scanning time, the above research is difficult to carry out in human subjects. In this case, animal models have become the main carrier for the study of vulnerable plaque contrast agents and drugs. Among them, apolipoprotein E deficiency (ApoE - / - ) Experimental mice are the most commonly used animal model. Therefore, there is an increasing demand for plaque magnetic resonance imaging methods for animals.

[0005] However, the main challenges faced by small animal plaque MRI are as follows:

[0006] (1) Small animals (e.g., experimental mice) are small in size, typically weighing 25-30 grams. Therefore, the overall magnetic resonance signal available for imaging is small, and the native signal-to-noise ratio is low. Furthermore, the number of coil channels suitable for small animals is usually small, making parallel acquisition and acceleration methods difficult to apply. These issues lead to very low imaging efficiency.

[0007] (2) The size of the aorta lumen and wall of small animals are only hundreds of microns and tens of microns respectively, which is not conducive to imaging.

[0008] The spatial resolution of the method is very high.

[0009] (3) The breathing and heartbeat of small animals are relatively fast, so the resulting respiratory motion artifacts and pulsation artifacts are more serious.

[0010] (4) Contrast agents will change the imaging parameters of blood. The effects of different contrast agents are not the same, and the parameters of contrast agents in the development stage are usually difficult to determine. Therefore, imaging technology based on the inherent relaxation parameters of blood is difficult to apply to the development and research of new contrast agents.

[0011] Therefore, how to improve the imaging efficiency of animal plaque magnetic resonance imaging, eliminate imaging artifacts, and improve the quality of imaging are technical problems that technical personnel in this field urgently need to solve.

[0012] Summary of the Invention

[0013] In view of this, the present application provides a method and system for magnetic resonance imaging of animal aortic plaques based on the cardiac saturation zone, which at least solves some of the above-mentioned technical problems. The method and system have the advantages of high imaging efficiency, light imaging artifacts, wide application scenarios and strong scalability.

[0014] To achieve the above objectives, the technical solutions adopted in this application are:

[0015] In a first aspect, an embodiment of the present application provides a method for magnetic resonance imaging of animal aortic plaques based on a cardiac saturation band, comprising the following steps:

[0016] S1. Use a magnetic resonance imaging scanner to obtain three-dimensional orthogonal positioning images of the animal in a fixed position, determine the position of the heart, and perform cardiac saturation zone positioning so that the saturation zone is parallel to the animal's trunk and completely covers the heart.

[0017] S2. adding the located cardiac saturation zone as a preparation module to an acquisition sequence of multiple magnetic resonance imaging techniques;

[0018] S3. Based on the positioning image and structural image, preset the imaging field of view close to the animal's spine and including the aorta;

[0019] S4. In the set acquisition sequence, respiratory gating triggering is turned on to obtain magnetic resonance images of animal aortic plaques with multiple contrasts.

[0020] Preferably, the animal is positioned and fixed in the following manner:

[0021] (1) Place the support pad at the bottom of the animal bed;

[0022] (2) placing a heating pad on the support pad and setting the water temperature of the heating pad to a constant preset value;

[0023] (3) placing the abdominal pad on the heating pad;

[0024] (4) placing a respiratory monitoring pad on the abdominal pad;

[0025] (5) Place the animal on all pads with its abdomen in contact with the respiratory monitoring pad;

[0026] (6) Place the receiving coil on the animal's back and press it tightly to cover the target imaging area, and fix the coil to the animal bed.

[0027] Preferably, the S1 specifically includes:

[0028] S11. Collect appropriate positioning:

[0029] Repeatedly adjust the animal's position so that the situator image satisfies the following conditions: the axial image is within the imaging area; the spine, heart, and liver are visible in the sagittal image; and the aorta, diaphragm, liver, and kidneys are visible in the coronal image.

[0030] S12. Positioning the imaging area:

[0031] Determine the imaging location and imaging parameters in the selected layer direction according to the research purpose;

[0032] In the anterior-posterior direction, the imaging area was made tangential to the animal's back;

[0033] In the left-right direction, ensure that the imaging area is symmetrical relative to the animal's spine;

[0034] Determine the relative position of the imaging area on the animal's aorta in the cranial and caudal directions;

[0035] S13. Locating the cardiac saturation zone:

[0036] Add a cardiac saturation band parallel to the animal's spine;

[0037] In the anterior-posterior direction, the cardiac saturation zone was placed adjacent to the imaging area;

[0038] According to the heart size, the width of the heart saturation band is adjusted to completely cover the animal's heart and pre-saturate the arterial blood signal ejected by the heart.

[0039] Preferably, in S12, after positioning the imaging area, the left-right direction is set as the frequency encoding direction, and the front-back direction is set as the phase encoding direction.

[0040] Preferably, in S2, the multiple magnetic resonance imaging techniques include but are not limited to: T1WI, TOF and DCE.

[0041] Preferably, in said S4, said multiple contrast magnetic resonance images of animal aortic plaques include but are not limited to: magnetic resonance structural images, magnetic resonance vascular images and magnetic resonance dynamic contrast-enhanced images.

[0042] In a second aspect, embodiments of the present application further provide a cardiac saturation band-based animal aortic plaque magnetic resonance imaging system, which utilizes the aforementioned cardiac saturation band-based animal aortic plaque magnetic resonance imaging method to rapidly acquire high-resolution, high-contrast animal aortic plaque images. The system comprises:

[0043] The magnetic resonance imaging positioning module is used to obtain three-dimensional orthogonal positioning images of the animal in a fixed position through a magnetic resonance scanner, determine the position of the heart, and locate the cardiac saturation band so that the saturation band is parallel to the animal's trunk and completely covers the heart;

[0044] A cardiac saturation band application module is used to add the positioned cardiac saturation band as a preparation module in the acquisition sequence of various magnetic resonance imaging technologies;

[0045] An imaging field of view setting module is used to preset an imaging field of view close to the animal's spine and including the aorta based on the positioning image and the structural image;

[0046] The imaging result acquisition module is used to start respiratory gating triggering in a set acquisition sequence to obtain magnetic resonance images of animal aortic plaques with multiple contrasts.

[0047] Compared with the prior art, this application has at least the following beneficial effects:

[0048] This application provides a method and system for magnetic resonance imaging of animal aortic plaques using cardiac saturation bands. This method can rapidly acquire high-resolution, high-contrast images of animal aortic plaques, minimizing image artifacts. The method offers advantages such as high imaging quality, high imaging efficiency, minimal artifacts, broad application scenarios, and strong scalability. Application of this method can aid in the screening of AS animal models and the development of diagnostic contrast agents and therapeutic drugs for plaques.

[0049] Other features and advantages of the present application will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0050] The technical solution of the present application is further described in detail below through the accompanying drawings and examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0052] The accompanying drawings are used to provide further understanding of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application.

[0053] FIG1 is a flow chart of a method for magnetic resonance imaging of animal aortic plaques based on a cardiac saturation zone according to an embodiment of the present application.

[0054] FIG2 is a schematic diagram of animal positioning provided in an embodiment of the present application.

[0055] FIG3 is a schematic diagram of a magnetic resonance imaging positioning method provided in an embodiment of the present application.

[0056] FIG4 is a schematic diagram of the HS-T1WI effect provided in an embodiment of the present application.

[0057] FIG5 is a schematic diagram of the HS-TOF effect provided in an embodiment of the present application.

[0058] FIG6 is a schematic diagram comparing the effects of HS-T1WI and HS-TOF provided in an embodiment of the present application.

[0059] FIG7 is a schematic diagram of the HS-DCE effect provided in an embodiment of the present application. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0061] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0062] 1 , the present application provides a method for magnetic resonance imaging of animal aortic plaques based on a cardiac saturation band, the method comprising the following steps:

[0063] S1. Use a magnetic resonance imaging scanner to obtain three-dimensional orthogonal positioning images of the animal in a fixed position, determine the position of the heart, and perform cardiac saturation zone positioning so that the saturation zone is parallel to the animal's trunk and completely covers the heart.

[0064] S2. In the acquisition sequence of multiple MRI techniques, a well-located cardiac saturation zone is added as a preparation module;

[0065] S3. Based on the positioning image and structural image, preset the imaging field of view close to the animal's spine and including the aorta;

[0066] S4. In the set acquisition sequence, respiratory gating triggering is turned on to obtain magnetic resonance images of animal aortic plaques with multiple contrasts.

[0067] The following uses mice as an example to illustrate the specific implementation of the present invention:

[0068] In this embodiment, the preferred hardware conditions include: a 9.4T Bruker Biospec horizontal field MRI scanner, a 112 / 86mm quadrature resonator transmitting coil, a 4-channel phased array receiving coil, a rat animal bed, a rat anesthesia mask, a mouse heating pad, and a mouse tooth bar. It should be noted that the selection of the above hardware is optimized based on the application scenario of this embodiment and does not affect the specific implementation of the method.

[0069] The animal experiments in this example were all approved by relevant organizations (e.g., the Animal Care and Use Committee of Tsinghua University). The experimental animals used were ApoE - / - Mice were anesthetized as follows: anesthesia was induced in mice with 3% isoflurane and 3 L / min oxygen outside the scanning room. The mice were then transferred to the animal bed of the MRI scanner and anesthesia was maintained with 1%-2% isoflurane and 1 L / min oxygen.

[0070] In a specific embodiment, the animal positioning method in this application is shown in Figure 2, which mainly illustrates how the animal is fixed on the animal bed to more effectively perform the next step of magnetic resonance imaging positioning. The sub-figures in Figure 2 are described as follows:

[0071] Figure 2A is a sagittal cross-section, with the mouse heart in gray. Using the mouse as a reference, in front of the mouse, its head is secured with a tooth bar to determine its anterior-posterior position within the animal bed, while its mouth and nose are secured within the anesthesia mask. Below the mouse, its body is padded, from bottom to top, with the following: a support pad to elevate the mouse's body overall; a heating pad to maintain body temperature; an abdominal pad to partially elevate the mouse's abdomen; and a respiratory monitoring pad to monitor the mouse's respiration and trigger respiratory gating during MRI data acquisition. Above the mouse, a receiving coil compresses the mouse's back to improve the signal-to-noise ratio.

[0072] Figure 2B is an axial cross-section, with the mouse heart in gray. The mouse is held in place by a gasket and coil, which correspond exactly to those in Figure 2A and are not described here.

[0073] In a specific embodiment, as shown in FIG2 , the specific process of the small animal positioning method is as follows:

[0074] (1) Place a support pad (preferably a foam pad) at the bottom of the animal bed to raise the mouse's body and bring it closer to the receiving coil to improve the signal-to-noise ratio.

[0075] (2) Place a heating pad on the foam pad and set the water temperature of the heating pad to a preset value (preferably 40 degrees Celsius) to keep the mouse warm during the scanning process and maintain its normal physiological function;

[0076] (3) Place the abdominal pad on the heating pad to locally elevate the imaging area and bring it closer to the receiving coil to improve the signal-to-noise ratio;

[0077] (4) Place a respiratory monitoring pad on the abdominal pad to monitor the mouse's breathing and trigger respiratory gating during magnetic resonance data acquisition;

[0078] (5) Place the mouse on all pads so that the front and back of the body hang naturally. Adjust the position of the mouse tooth bar so that the mouse abdomen overlaps with the abdominal pad. At the same time, the upper body of the mouse, especially the heart (cardiac saturation zone position), is always lower than the mouse abdomen (imaging area);

[0079] (6) Place the receiving coil on the mouse's back and press it tightly to cover the target imaging area, and secure the coil to the animal bed with tape to reduce motion artifacts.

[0080] In a specific embodiment, the magnetic resonance imaging positioning method of the present application is shown in FIG3 , and its sub-figures are described as follows:

[0081] Figure 3A is a schematic diagram of the imaging positioning method, where the mouse body is outlined in gray, the heart (white) is located in the lower left thorax, and the aorta (white) extends from the heart along the mouse's back to the tail. The black hollow rectangle represents the cardiac saturation zone, which runs parallel to the mouse body. Its thickness depends on the size of the heart and needs to completely cover the heart. The light black solid rectangle represents the imaging area, and the small black rectangle represents the imaging layer. The specific location of the imaging area and the imaging parameters of the selected layer direction can be determined by the research purpose.

[0082] Figures 3B to 3D are axial, sagittal, and coronal scout images, respectively. The white hollow rectangle represents the cardiac saturation zone, the light white solid rectangle represents the imaging area, and the small white rectangle represents the imaging level.

[0083] In a specific embodiment, as shown in FIG3 , the magnetic resonance imaging positioning method process is as follows:

[0084] (1) Acquire appropriate positioning images. Repeatedly adjust the mouse position so that the positioning images meet the following requirements to improve positioning efficiency: the axial image is within the imaging area; the spine, heart, and liver are observed in the sagittal image; and the aorta, diaphragm, liver, and kidneys are observed in the coronal image.

[0085] (2) Position the imaging area. First, determine the imaging site and the imaging parameters for the selected layer direction according to the research purpose. In the anterior-posterior direction, refer to Figures 3B and 3C and try to make the imaging area tangent to the mouse's back to increase the effective imaging area; in the lateral direction, refer to Figures 3B and 3D to ensure that the imaging area is symmetrical relative to the spine; in the cranial-caudal direction, refer to Figures 3C and 3D to determine the relative position of the imaging area on the aorta. After positioning, set the lateral direction as the frequency encoding direction and the anterior-posterior direction as the phase encoding direction to shorten the scanning time and prevent wrap-around artifacts.

[0086] (3) Position the cardiac saturation band. First, add a spatial saturation band parallel to the coronal plane and parallel to the mouse's back. In the anterior-posterior direction, using Figures 3B and 3C as a reference, position the cardiac saturation band close to the imaging area to prevent curling artifacts. Adjust the width of the cardiac saturation band to completely cover the mouse heart based on the heart size, saturating the arterial blood signal ejected from the heart to achieve a black blood effect.

[0087] In a specific embodiment, after the small animal is positioned and the MRI is positioned, an imaging field of view close to the animal's spine and including the aorta is preset based on the positioning image and structural image; respiratory gating is enabled to trigger data acquisition; further, aortic plaque imaging results are output by combining various MRI techniques; this application can be applied to MRI of various modalities (such as T1WI, TOF, and DCE) to output MRI structural images, vascular images, and dynamic contrast-enhanced images. The specific effects are as follows:

[0088] Figure 4 shows the effect of T1-weighted image (HS-T1WI) based on cardiac saturation band in this application. T1WI is a commonly used magnetic resonance structural image used to observe the anatomical structure of tissues. The first row in the figure is HS-T1WI, the second row is T1WI with the same FOV (field of view) without saturation band, and the third row is T1WI with two saturation bands applied close to the imaging area in the full FOV axis, which is used as the gold standard. The end of each row is the total scanning time of each method (a total of 11 layers), and each column is a comparison of the effects of different technologies at the same level in the same mouse, with three layers selected as an example. Compared with the second row, HS-T1WI completely eliminated the curling artifact at the cost of only 16% increase in scanning time; compared with the third row, HS-T1WI obtained a black blood effect comparable to the gold standard with 42% scanning time.

[0089] Figure 5 shows the effect of the time-of-flight technology (HS-TOF) based on the cardiac saturation band in this application. TOF is a bright blood technology commonly used in magnetic resonance angiography, which is used to observe blood vessel morphology. However, due to the high blood signal, TOF cannot be directly applied to plaque imaging. In this application, a cardiac saturation band is applied on the basis of TOF to display plaques. The first row in the figure (Figure 5A-Figure 5C) is HS-TOF, and the second row (Figure 5D-Figure 5F) is TOF without saturation band in the full FOV. The arrows point to the plaque positions. Each column is a comparison of the effects of different technologies at the same level in the same mouse, and three layers are selected as an example. In the second row of images, the magnetic resonance signal of the plaques tightly attached to the inner wall of the blood vessel is overwhelmed by the dominant blood magnetic resonance signal, and cannot be used to observe the plaques at all, and the pulsation artifacts are more obvious. In comparison, HS-TOF eliminates the blood signal, can clearly display the plaque position, and completely eliminates the pulsation artifacts. In addition, this technology does not rely on the intrinsic relaxation parameters of blood and is more suitable for complex situations where blood imaging parameters change after the injection of contrast agents or drugs.

[0090] Figure 6 is a comparison of the effects of HS-T1WI and HS-TOF. The first row (Figure 6A-Figure 6C) is HS-TOF, the second row (Figure 6D-Figure 6F) is HS-T1WI, and the third row (Figure 6G-Figure 6I) is the superposition effect of HS-TOF on HS-T1WI. The arrows indicate the location of the plaque. Each column is a comparison of the effects of different technologies at the same level in the same mouse, with three layers selected as an example. The results show that the plaque location information obtained in HS-TOF and HS-T1WI is basically the same. Therefore, accurate multi-contrast plaque imaging results can be obtained by combining HS-TOF and HS-T1WI.

[0091] Figure 7 shows the dynamic contrast enhancement (HS-DCE) effect based on the cardiac saturation zone in this application. DCE is a technology that uses a fast imaging sequence in magnetic resonance imaging to obtain continuous multi-phase images after intravenous injection of contrast agents. It is often used in pharmacokinetic studies of contrast agents and drugs, and has very high requirements for time resolution. The figure shows the baseline image at the same level and 8 frame images after injection of contrast agents. The arrows indicate the location of the plaque. The HS-DCE results can clearly show the dynamic changes of the plaque after the injection of the contrast agent. The time resolution in this embodiment is 4 seconds. The pure water signal above the image can be used for quantitative analysis.

[0092] From the description of the above embodiments, those skilled in the art can understand that the present application provides a method for magnetic resonance imaging of animal aortic plaques based on cardiac saturation bands, which has at least the following advantages and beneficial effects:

[0093] First, achieving magnetic resonance imaging of animal aortic plaques while improving imaging efficiency. The cardiac saturation band in this application has the following functions: 1. It pre-saturates the arterial blood signal ejected from the heart, rendering it signal-free when flowing through the imaging area, thereby achieving a black blood effect and effectively displaying plaques; 2. It also pre-saturates the signal from the lower abdomen, reducing the FOV in the phase encoding direction without introducing wrap-around artifacts. This makes it possible to improve spatial resolution at the same acquisition time, shorten acquisition time at the same spatial resolution, or find a compromise between the two, all of which improve imaging efficiency.

[0094] Second, imaging artifacts are eliminated. Since the arterial blood signal ejected by the heart is saturated, pulsation artifacts caused by it are eliminated. Respiratory motion artifacts are eliminated by using respiratory gating during imaging. Furthermore, a cardiac saturation band pre-saturates the signal outside the FOV in the phase encoding direction, eliminating wrap-around artifacts.

[0095] Third, the method proposed in this application is applicable to a variety of magnetic resonance imaging modalities, including but not limited to structural imaging, vascular imaging, and dynamic contrast enhancement. The three aforementioned applications are illustrated in this application, each of which can effectively display aortic plaques and achieve different application purposes.

[0096] Fourth, it is highly scalable. The animal positioning method and magnetic resonance imaging positioning method based on the cardiac saturation zone in this application are not only limited to use on 9.4T small animal magnetic resonance scanners, but are also applicable to human or other animal horizontal field magnetic resonance scanners with various field strengths (such as 1.5T, 3T, 5T, 7T and 11.7T, etc.). This method can be used as an independent animal aortic plaque magnetic resonance imaging pre-saturation module, applied to a variety of magnetic resonance imaging sequences, and combined with existing parallel acquisition and rapid reconstruction methods to further improve acquisition efficiency.

[0097] Furthermore, the present application also provides a cardiac saturation band-based animal aortic plaque magnetic resonance imaging system, which is applied to the aforementioned cardiac saturation band-based animal aortic plaque magnetic resonance imaging method to rapidly acquire high-resolution, high-contrast animal aortic plaque images. The system comprises:

[0098] The magnetic resonance imaging positioning module is used to obtain three-dimensional orthogonal positioning images of the animal in a fixed position through a magnetic resonance scanner, determine the position of the heart, and locate the cardiac saturation band so that the saturation band is parallel to the animal's trunk and completely covers the heart;

[0099] A cardiac saturation band application module is used to add the positioned cardiac saturation band as a preparation module in the acquisition sequence of various magnetic resonance imaging technologies;

[0100] An imaging field of view setting module is used to preset an imaging field of view close to the animal's spine and including the aorta based on the positioning image and the structural image;

[0101] The imaging result acquisition module is used to start respiratory gating triggering in a set acquisition sequence to obtain magnetic resonance images of animal aortic plaques with multiple contrasts.

[0102] The system provided in the embodiment of the present application has the same implementation principle and technical effects as those in the aforementioned method embodiment. For the sake of brief description, for matters not mentioned in the system embodiment, reference can be made to the corresponding content in the aforementioned method embodiment, which will not be repeated here.

[0103] Furthermore, an embodiment of the present application also provides a storage medium on which one or more programs readable by a computing device are stored, and the one or more programs include instructions. When the instructions are executed by the computing device, the computing device executes a cardiac saturation band-based animal aortic plaque magnetic resonance imaging method in the Sugi Tree embodiment.

[0104] In the embodiments of the present application, the storage medium may be, for example, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof. More specific examples of storage media (a non-exhaustive list) include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disc (DVD), a memory stick, a floppy disk, a mechanical encoding device, and any suitable combination thereof.

[0105] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0106] It should be noted that the word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The present application can be implemented by means of hardware comprising several distinct components and by means of a suitably programmed computer.

[0107] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0108] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for magnetic resonance imaging of animal aortic plaques based on cardiac saturation band, characterized in that: The method includes: S1. Obtain three-dimensional orthogonal positioning images of the animal in a fixed position through a magnetic resonance scanner, determine the position of the heart, and locate the heart saturation zone so that the saturation zone is parallel to the animal's trunk and completely covers the heart; S2. In the acquisition sequence of multiple magnetic resonance imaging techniques, the located cardiac saturation zone is added as a preparation module; S3. Based on the positioning image and the structural image, preset the imaging field of view close to the animal's spine and including the aorta; S4. In the set acquisition sequence, start the respiratory gating trigger to obtain magnetic resonance images of animal aortic plaques with multiple contrasts.

2. The method for magnetic resonance imaging of animal aortic plaques based on cardiac saturation band according to claim 1, characterized in that: The animal's position is fixed in the following ways: (1) Place the support pad at the bottom of the animal bed; (2) placing a heating pad on the support pad and setting the water temperature of the heating pad to a constant preset value; (3) placing an abdominal pad on the heating pad; (4) placing a respiratory monitoring pad on the abdominal pad; (5) Place the animal on all pads with the animal's abdomen in contact with the respiratory monitoring pad; (6) Place the receiving coil on the animal's back and press it tightly to cover the target imaging area, and fix the coil to the animal bed.

3. The method for magnetic resonance imaging of animal aortic plaques based on cardiac saturation band according to claim 1, characterized in that: The S1 specifically includes: S11. Collect suitable positioning: Repeatedly adjust the animal position to ensure that the positioning image meets the following requirements: the axial image is within the imaging area; the spine, heart, and liver are observed in the sagittal image; and the aorta, diaphragm, liver, and kidneys are observed in the coronal image. S12. Positioning imaging area: Determine the imaging location and imaging parameters in the selected layer direction according to the research purpose; In the anterior-posterior direction, the imaging area was made tangential to the animal's back; In the left-right direction, ensure that the imaging area is symmetrical relative to the animal's spine; In the cranio-caudal direction, determine the relative position of the imaging area on the animal's aorta; S13, positioning the heart saturation zone: Add a heart saturation band parallel to the animal's spine; In the anterior-posterior direction, the cardiac saturation zone was placed adjacent to the imaging area; According to the size of the heart, the width of the heart saturation band is adjusted to completely cover the animal's heart and pre-saturate the arterial blood signal ejected by the heart.

4. The method for magnetic resonance imaging of animal aortic plaques based on cardiac saturation band according to claim 3, characterized in that: In the above S12, after positioning the imaging area, the left-right direction is set as the frequency encoding direction, and the front-back direction is set as the phase encoding direction.

5. The method for magnetic resonance imaging of animal aortic plaques based on cardiac saturation band according to claim 1, characterized in that: In S2, the multiple magnetic resonance imaging techniques include but are not limited to: T1WI, TOF and DCE.

6. The method for magnetic resonance imaging of animal aortic plaques based on cardiac saturation band according to claim 1, characterized in that: In S4, the multiple contrast magnetic resonance images of animal aortic plaques include but are not limited to: magnetic resonance structural images, magnetic resonance vascular images and magnetic resonance dynamic contrast enhanced images.

7. A magnetic resonance imaging system for animal aortic plaques based on cardiac saturation bands, characterized in that: When used, the method for magnetic resonance imaging of animal aortic plaques based on a cardiac saturation band as described in any one of claims 1 to 6 is performed to achieve rapid acquisition of high-resolution, high-contrast animal aortic plaque images, the system comprising: The magnetic resonance imaging positioning module is used to obtain three-dimensional orthogonal positioning images of the animal in a fixed position through a magnetic resonance scanner, determine the position of the heart, and locate the heart saturation band so that the saturation band is parallel to the animal's trunk and completely covers the heart; A cardiac saturation band application module, used to add the positioned cardiac saturation band as a preparation module in the acquisition sequence of various magnetic resonance imaging techniques; An imaging field of view setting module is used to preset an imaging field of view close to the animal's spine side and including the aorta according to the positioning image and the structural image; The imaging result acquisition module is used to start the respiratory gating trigger in the set acquisition sequence to obtain magnetic resonance images of animal aortic plaques with multiple contrasts.

Images