An iron agent enhanced whole body vascular multi-modal magnetic resonance imaging method and system

Abstract

The application discloses a kind of iron agent enhanced whole body blood vessel multi-modal magnetic resonance imaging method, system, the method comprises: after target is divided into multiple scanning stations from head to foot, iron agent enhanced whole body blood vessel bright blood imaging is carried out;Automatic positioning whole body blood vessel stenosis and quantifying its stenosis degree, and output the scanning station and position range information of blood vessel stenosis region;Judge whether there is blood vessel stenosis region meeting condition;According to its spatial position information, guide MRI system examination bed to move for blood vessel stenosis region meeting condition, and carry out local black blood imaging with not less than the spatial range of blood vessel stenosis region;Blood vessel stenosis region exists in interval period and carries out local bright blood imaging to the scanning station, obtains blood vessel cavity structure image;Local bright blood imaging is registered with whole body blood vessel bright blood imaging, and the information transmission of blood vessel stenosis region is completed, and local inflammation imaging is carried out.The application realizes the multi-modal imaging evaluation of whole body blood vessel in clinically acceptable scanning time.

Description

Technical Field

[0001] This invention belongs to the field of medical imaging, specifically relating to an iron-enhanced whole-body vascular multimodal magnetic resonance imaging method and system. Background Technology

[0002] Vascular diseases are characterized by two important features. First, they are systemic diseases; lesions in one region often foreshadow lesions in other regions. For example, atherosclerosis and Takayasu arteritis often involve lesions in multiple vascular beds throughout the body. Contrast-enhanced whole-body vascular bright-blood imaging (a method that highlights the vascular lumen by making the blood appear brighter) not only increases the chance of incidentally discovering lesions but also provides additional effective diagnostic information. Second, the pathological progression of vascular diseases is multifaceted, often accompanied by structural abnormalities of the vessel wall and local inflammation, in addition to stenosis or blockage of the vessel lumen. Bright-blood imaging is very effective in detecting vascular lesions such as stenosis, but it is weak in assessing the vessel wall. Dark-blood imaging provides a powerful complement to bright-blood imaging in the diagnosis of vascular diseases, especially in the visualization of atherosclerotic plaques (vessel walls). It is characterized by suppressing the blood signal, making the blood / vessel lumen appear as a low / dark signal in dark-blood imaging, thus primarily highlighting the vessel wall or intravascular thrombi. Inflammatory imaging provides more information on the inflammatory state of plaques, which is widely considered to be of great value in predicting plaque stability. In other words, multimodal imaging, which combines bright blood, dark blood, and inflammation imaging, is particularly necessary in the assessment of vascular diseases.

[0003] Iron-based contrast agents (hereinafter referred to as iron agents) are a new type of iron-based magnetic resonance imaging (MRI) contrast agents. Compared with gadolinium-based contrast agents, they have better renal safety, longer blood half-life, and stronger performance in shortening T1 and T2 / T2* relaxation time (Knobloch G, Colgan T, Wiens CN, et al. Investigative radiology, 2018, 53(5):257; Colbert, Caroline M et al. Journal of magnetic resonance imaging: JMRI vol.57, 6(2023):1819-1829.). These properties enable the whole-body vascular bright blood imaging modality enhanced by iron agents to visualize the whole-body vascular lumen in clinical practice. It is a powerful diagnostic tool for analyzing vascular stenosis from a systemic perspective (Nayak, Anjali B., et al. Pediatric nephrology 30(2015):515-521.). Based on the property of iron to shorten T2 / T2* relaxation time, iron-enhanced black-blood imaging has been shown to be blood flow-independent, thus achieving better black-blood imaging results (Nguyen KL, Park EA, Yoshida T, et al. Journal of cardiovascular magnetic resonance, 2017, 19(1):1-10; Li W, Salanitri J, Tutton S, et al. Radiology, 2007, 242(3):873-881.). Meanwhile, the aggregation of iron-phagocytic macrophages at the site of inflammation alters local tissue magnetization and relaxation time, thus bringing new opportunities for inflammation visualization. Iron-enhanced inflammation imaging has been shown to assess carotid plaque inflammation tens of hours after contrast agent injection (Usman A, Patterson AJ, Yuan J, et al. Scientific Reports, 2020, 10(1):1808.). In short, the feasibility and diagnostic value of iron-enhanced multimodal imaging of bright blood, dark blood, and inflammation have been demonstrated.

[0004] However, current use of these three modalities remains a single-modal imaging approach for individual patients. Based on a literature review, we have not seen any reports of iron-enhanced bright blood, dark blood, and inflammation imaging performed on the same individual after a single iron injection. Based on our clinical experience, performing enhanced bright blood, dark blood, and inflammation imaging after a single iron injection is theoretically feasible. This multimodal imaging approach helps achieve a comprehensive assessment of vascular diseases in terms of lumen, vessel wall, and inflammatory activity. However, its main difficulty lies in the extremely time-consuming nature of performing imaging of the three modalities of the whole-body vascular bed from head to toe, significantly offsetting the benefits of the multidimensional diagnostic information provided by this multimodal imaging and thus preventing its clinical acceptance. The key to overcoming the current lack of iron-enhanced whole-body multimodal imaging protocols for vascular diseases lies in reconciling the beneficial effect of comprehensive assessment with the overall scanning time, especially since dark blood imaging and inflammation imaging are both relatively time-consuming. Specifically, due to the systemic nature and multifaceted progression of vascular diseases, whole-body vascular multimodal imaging is extremely valuable. However, the required scanning space is several times that of conventional single vascular bed assessment (generally about 4-6 times). If we simply expand the scanning space of a single modality, the corresponding overall scanning time will be unacceptable in clinical practice. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide an iron-enhanced whole-body vascular multimodal magnetic resonance imaging method and system. This method can achieve multimodal imaging assessment of whole-body vascular system within a clinically acceptable scanning time, and provide visualization of the location of vascular lesions, vascular lumen, vascular wall and vascular wall inflammatory response.

[0006] Technical solution: The present invention provides an iron-enhanced whole-body vascular multimodal magnetic resonance imaging method, comprising the following steps:

[0007] After the target was divided into multiple scanning stations from head to toe, iron-enhanced whole-body vascular bright blood imaging was performed.

[0008] Based on the vascular structure and spatial location information in whole-body vascular bright blood imaging, the system automatically locates and quantifies the degree of stenosis in whole-body blood vessels, and outputs the scanning station and location range information of the stenotic area.

[0009] Determine if a vascular stenosis area exists that meets the criteria; if it does, proceed to the next step; otherwise, end the process.

[0010] For vascular stenosis areas that meet the criteria, the MRI system examination table is moved according to the spatial location information of the vascular stenosis area, so that the vascular stenosis area is included in the effective scanning range, and local black blood imaging is performed with a spatial range not less than that of the vascular stenosis area.

[0011] During the interval period, local bright blood imaging is performed on the scanning station where there is vascular stenosis, thereby obtaining images of the vascular lumen structure;

[0012] The local bright blood imaging of the scanning station is registered with the whole-body vascular bright blood imaging to complete the information transmission of the vascular stenosis area and to perform local inflammation imaging.

[0013] Furthermore, adjacent scanning stations among the plurality of scanning stations maintain a moderate degree of spatial overlap for registration, stitching, and subsequent analysis of whole-body images.

[0014] Furthermore, adjacent scanning stations among the plurality of scanning stations maintain a spatial overlap of 7-15 cm on the z-axis of the MRI system's world coordinate system.

[0015] Furthermore, the location range information includes the scanning station number where the vascular stenosis area is located and the spatial range in the MRI system's world coordinate system.

[0016] Furthermore, the iron agent is ferumoxytol or MoldayION.

[0017] Furthermore, during the interval period, based on the scanning station number of the vascular stenosis area that meets the output conditions, local bright blood imaging is performed on the scanning station corresponding to the scanning station number.

[0018] Furthermore, the vascular cavity structure image is a subset of whole-body vascular bright blood imaging.

[0019] Based on the same inventive concept, the present invention provides an iron-enhanced whole-body vascular multimodal magnetic resonance imaging system, comprising:

[0020] The bright blood imaging acquisition module is used to acquire whole-body bright blood images of blood vessels from head to toe, divided into multiple scanning stations and enhanced with iron.

[0021] The vascular stenosis area localization module is used to automatically locate vascular stenosis throughout the body and quantify its degree of stenosis based on vascular structure information and spatial location information in whole-body vascular bright blood imaging, and output the scanning station and location range information of the vascular stenosis area.

[0022] The vascular stenosis region identification module is used to determine whether there is a vascular stenosis region that meets the conditions; if it exists, proceed to the next step; otherwise, the process ends.

[0023] The black-blood imaging acquisition module guides the MRI system examination table to move according to the spatial location information of the stenotic area of ​​the blood vessel, so that the stenotic area is included in the effective scanning range and local black-blood imaging is performed with a spatial range not less than that of the stenotic area.

[0024] The local bright blood imaging module is used to perform local bright blood imaging on scanning stations with vascular stenosis areas at intervals, thereby obtaining images of the vascular lumen structure.

[0025] The inflammation imaging acquisition module is used to register the local bright blood imaging from the scanning station with the whole-body vascular bright blood imaging to complete the information transmission of the vascular stenosis area and to perform local inflammation imaging.

[0026] Based on the same inventive concept, the present invention provides an iron-enhanced whole-body vascular multimodal magnetic resonance imaging device, comprising a processor and a memory, wherein the memory stores computer instructions, and the processor is used to execute the computer instructions stored in the memory. When the computer instructions are executed by the processor, the electronic device implements the steps of the iron-enhanced whole-body vascular multimodal magnetic resonance imaging method described above.

[0027] Based on the same inventive concept, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described iron-enhanced whole-body vascular multimodal magnetic resonance imaging method.

[0028] Beneficial effects: Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0029] (1) By combining whole-body vascular bright blood imaging with local dark blood and inflammation imaging, the vascular structure and MRI system scanning spatial location information in whole-body vascular bright blood imaging with the shortest scanning time are fully utilized to guide local dark blood and inflammation imaging. This approach balances the overall scanning time while comprehensively evaluating the beneficial effect, and ultimately achieves iron-enhanced whole-body vascular multimodal magnetic resonance imaging under the premise that the overall scanning time is clinically acceptable.

[0030] (2) By applying local bright blood imaging again as a localization reference during the inflammation imaging stage, spatial registration of three modal images of local bright blood imaging, whole-body bright blood imaging, and local dark blood imaging can be achieved, thereby improving the availability / success rate and interpretability of single-scan images of inflammation imaging.

[0031] (3) Thanks to the long blood half-life of iron supplements, this regimen is highly reproducible. This makes it particularly beneficial for pediatric patients with poor tolerance and compliance. It also means greater operability and wider applicability, especially in primary healthcare institutions. Attached Figure Description

[0032] Figure 1 This is a schematic flowchart of an iron-enhanced whole-body vascular multimodal magnetic resonance imaging method disclosed in an embodiment of the present invention;

[0033] Figure 2This is an effect diagram of an iron-enhanced whole-body vascular multimodal magnetic resonance imaging method disclosed in an embodiment of the present invention;

[0034] Figure 3 This is an effect diagram of an iron-enhanced whole-body vascular multimodal magnetic resonance imaging method disclosed in another embodiment of the present invention;

[0035] Figure 4 This is a schematic diagram of the structure of an iron-enhanced whole-body vascular multimodal magnetic resonance imaging system disclosed in an embodiment of the present invention;

[0036] Figure 5 This is a schematic diagram of the structure of an iron-enhanced whole-body vascular multimodal magnetic resonance imaging device disclosed in an embodiment of the present invention. Detailed Implementation

[0037] The technical solution of the present invention will now be described in detail with reference to specific embodiments and accompanying drawings.

[0038] Example 1

[0039] Please see Figure 1 , Figure 1 This is a schematic flowchart of an iron-enhanced whole-body vascular multimodal magnetic resonance imaging method disclosed in an embodiment of the present invention. Figure 1 The described imaging method is applied in medical imaging, such as for whole-body vascular imaging, and the embodiments of the present invention are not limited thereto. Figure 1 As shown, this iron-enhanced whole-body vascular multimodal magnetic resonance imaging method may include the following operations:

[0040] S110: After acquiring the target from head to toe and dividing it into multiple scanning stations, perform iron-enhanced whole-body vascular bright blood imaging.

[0041] In this step, the iron agent can be ferumoxytol or other iron-based contrast agents with similar MRI and pharmacokinetics properties, such as MoldayION.

[0042] In this step, due to the limited effective scanning space of the MRI system, it is performed by a multi-station scanning method from head to toe.

[0043] In this step, adjacent scanning stations among multiple scanning stations maintain a moderate spatial overlap, thereby enabling the registration, stitching, and subsequent analysis of whole-body images.

[0044] In this embodiment, adjacent scanning stations among multiple scanning stations maintain a spatial overlap of 7-15 cm on the z-axis of the MRI system's world coordinate system.

[0045] The first step in this protocol is whole-body vascular bright-blood imaging. This modality, using only T1-weighted sequences, is more time-efficient than black-blood imaging and inflammation imaging, typically completing the task within approximately 5 minutes. The imaging timeframe can range from immediately after injection to several hours later. This extended window is primarily due to the long blood half-life of iron, which can last for tens of hours. Based on clinical trial results, it is preferable to perform the imaging immediately after injection, as this results in the highest blood drug concentration and greater MRI bright-blood signal gain. The MRI physics basis for iron-enhanced whole-body vascular bright-blood imaging is that iron significantly shortens the longitudinal relaxation time of blood (i.e., significantly shortens the T1 relaxation time, which causes the blood / vascular lumen to appear as a bright signal on T1-weighted images compared to the vessel wall or other background tissue, hence the term "bright-blood imaging"). The primary purpose of iron-enhanced whole-body vascular bright-blood imaging is to visualize and determine whether varying degrees of stenosis exist in the vascular lumen throughout the body.

[0046] S120: Based on the vascular structure and spatial location information in whole-body vascular bright blood imaging, it automatically locates stenosis of blood vessels throughout the body, quantifies the degree of stenosis, and outputs the scanning station and location range information of the stenotic area.

[0047] In this step, based on the vascular structure information and spatial location information in the whole-body vascular bright blood imaging enhanced by iron, the degree and location of vascular stenosis in various parts of the body are quantified and output; among them, the spatial location information includes the scanning station number of each (multiple) vascular stenosis area and the spatial range in the world coordinate system of the MRI system.

[0048] Iron-enhanced whole-body vascular bright-blood imaging provides structural and locational information of the entire vascular lumen with extremely high time efficiency. This enables the automated localization and quantification of vascular stenosis throughout the body (multiple locations / multiple sites) using automatic stenosis rating algorithms. This process specifically involves stitching images from multiple scanning stations, vessel segmentation, extraction, tracking, and lumen diameter measurement. Several algorithms have been proposed and integrated to achieve automated analysis. For example, McNeil, A. proposed an automatic detection and grading method for luminal stenosis based on whole-body magnetic resonance angiography in his paper "Computer-Assisted Analysis of Arterial Narrowing in Whole-Body Magnetic Resonance Angiography". This approach establishes a connection between the location detection and stenosis rate quantification of whole-body vascular lumen stenosis and the MRI system's world coordinate system. Specifically, it incorporates the DICOM format medical image header file's recording of spatial location information such as the MRI system's scanning area, orientation, and voxel size. Based on this, the scanning station number and actual physical spatial extent of the vascular stenosis can be calculated. For example, after performing iron-enhanced whole-body vascular imaging using a gradient echo T1-weighted sequence, we obtain individual 3D DICOM images from multiple scanning stations (where the image information consists of multiple 3D matrices, and scanning parameters are included in the header file). Combining the image orientation, image position, image matrix, and voxel size information contained in the DICOM header file, the spatial position of any voxel point in the 3D matrix obtained at each scanning station within the MRI system's world coordinate system can be uniquely determined. Therefore, the spatial range of any narrow point at each station can be calculated. In this scheme, the spatial position information in the MRI system's world coordinate system guides the automatic movement of the MRI examination table to the effective scanning range for local scanning.

[0049] S130: Determine if there is a vascular stenosis area that meets the conditions; if so, proceed to the next step; otherwise, end the process.

[0050] In this step, the setting for the degree of vascular stenosis is variable, which refers to two aspects: First, vascular stenosis can be judged using the diameter stenosis rate (i.e., the ratio of the diameter of the stenosis to the diameter of the normal blood vessel) or the area stenosis rate (i.e., the ratio of the cross-sectional area of ​​the stenosis to the area of ​​the normal blood vessel); second, the specific threshold is variable. For example, here, a diameter stenosis rate ≥5% means that the degree of stenosis is described according to the diameter stenosis rate and the threshold is set artificially to 5%, but this threshold will change depending on the specific needs of the scenario.

[0051] In this embodiment, it is determined whether there is a vascular stenosis area that meets the conditions among the above (multiple) stenosis areas. In this embodiment, the diameter stenosis rate of the vascular stenosis area is set to be ≥5% as the condition, that is, a stenosis threshold of 5% of the vascular diameter is set. If there is a stenosis that meets this condition, the next step is carried out; otherwise, the examination is directly terminated.

[0052] S140: For vascular stenosis areas that meet the conditions, the MRI system examination table is moved according to the spatial location information of the vascular stenosis area, so that the vascular stenosis area is included in the effective scanning range, and local black blood imaging is performed with a spatial range not less than that of the vascular stenosis area.

[0053] In this step, for eligible vascular stenosis areas, the MRI system examination table is moved according to the spatial location information of the vascular stenosis area, so that the vascular stenosis area is included in the effective scanning range, and local black-blood imaging is performed in a spatial range not less than the volume of the vascular stenosis area, until local black-blood imaging of all vascular stenosis areas is completed.

[0054] Since local dark-blood imaging is performed after whole-body bright-blood imaging, the target maintains the same spatial position relative to the MRI scan table as in whole-body bright-blood imaging. Therefore, the spatial location information of the vascular stenosis calculated in the previous step can be used to guide the (multiple) automatic table movement of the MRI scan table, using a spatial range no smaller than the stenosis area as the scan area, and continuing to perform local dark-blood imaging including the stenosis area. Using a spatial range no smaller than the stenosis area as the scan area is easy to understand; it means that the area where the vascular stenosis is located needs to be included to achieve assessment of the vessel wall at the stenosis site in dark-blood imaging.

[0055] The localized dark-blood imaging obtained in this step achieves two main benefits: it adds another modality of acquisition (clinically useful), and it facilitates the interpretation and understanding of bright-blood imaging and inflammation imaging data. S150: During the interval, localized bright-blood imaging is performed on the scanning station where there is vascular stenosis, thereby obtaining images of the vascular lumen structure.

[0056] In this step, within 24-48 hours after drug administration, based on the scanning station numbers of the (multiple) vascular stenosis areas that meet the previously output criteria, local bright blood imaging is first performed at the scanning station corresponding to these scanning station numbers to acquire the vascular lumen structure image again. Since this is a local scan, the scanning time is shorter than the previous whole-body bright blood scan. At the same time, the vascular lumen structure image acquired by this local bright blood scan is a subset of the previously acquired whole-body bright blood image.

[0057] The target will return to the MRI examination table 24-48 hours after iron injection for inflammatory imaging. Since the target's position relative to the MRI examination table changes upon leaving and returning, a local bright-blood imaging will be performed first, based on the previously output scan station number indicating vascular stenosis, to obtain a vascular structure image. This vascular structure image serves as a localization reference for image registration with the previous whole-body bright-blood imaging, thereby transmitting spatial location information of the vascular stenosis area.

[0058] S160: Registers the local bright blood imaging of the scanning station with the whole-body vascular bright blood imaging to complete the information transmission of the vascular stenosis area and perform local inflammation imaging.

[0059] In this step, the local bright blood images from the aforementioned (multiple) scanning stations are spatially registered with the previous whole-body bright blood images to transfer spatial location information of the vascular stenosis area. Similar to the previous local dark blood imaging, the MRI system's examination table is moved according to the spatial location information of the stenosis that meets the conditions, so that the vascular stenosis area is included within the effective scanning range, and local inflammation imaging is performed within a spatial range not smaller than the volume of the stenosis area. The examination ends after completion. Preferably, the scanning range of the local inflammation imaging is consistent with the scanning range of the local dark blood imaging in step S140, which is more conducive to the comparison and interpretation of multimodal imaging results.

[0060] After the MRI system automatically moves the bed, the area to be scanned is a spatial range no smaller than the narrowed region, and inflammatory imaging of the vascular stenosis area continues. This allows for precise control of the inflammatory imaging scan range at the vascular stenosis site without requiring the target to be positioned exactly the same as the initial MRI bed setup (it is almost impossible to maintain exactly the same setup twice before and after the target leaves and returns to the MRI bed). The examination ends after the local inflammatory imaging is completed.

[0061] The present invention adopts a method that organically combines whole-body vascular bright blood imaging with local dark blood and inflammation imaging. It makes full use of the vascular structure and MRI system scanning spatial location information in whole-body vascular bright blood imaging, which has the shortest scanning time, to guide local dark blood and inflammation imaging. Ultimately, it achieves the goal of comprehensive analysis of vascular diseases under the premise that the overall time is clinically acceptable.

[0062] Local dark blood imaging can be registered with whole-body bright blood imaging because it is performed immediately after whole-body bright blood imaging, allowing for spatial registration. Similarly, local inflammation imaging is performed immediately after local bright blood imaging, and the two can also be registered together. Furthermore, local bright blood imaging, as a subset, can be registered with whole-body bright blood imaging. This means that local dark blood and local inflammation images can be registered together for analysis through whole-body bright blood imaging, which is beneficial for image interpretation.

[0063] like Figure 2 As shown, in one specific embodiment of the present invention, according to Figure 1 The program flow achieved the following results:

[0064] The whole body was scanned by 6 scanning stations, with a 10cm z-axis spatial overlap between adjacent scanning stations. The whole body vascular bright blood imaging enhanced by ferumoxytol and the registration, stitching and analysis of the whole body images were successfully completed. In this embodiment, the stenosis condition was set to a diameter stenosis rate of ≥5%. The output results showed that the subject did not have vascular stenosis that met the condition, so the examination was terminated.

[0065] like Figure 3 As shown, in one specific embodiment of the present invention, according to Figure 1 The program flow achieved the following results:

[0066] The whole body was scanned at 6 scanning stations, with a 10cm overlap between adjacent scanning stations along the z-axis. This successfully achieved ferumoxytol-enhanced whole-body vascular imaging. Figure 3 The registration, stitching, and analysis of Figure (a) and the whole-body image are described. In this specific embodiment, the stenosis condition is set to a diameter stenosis rate ≥5%, and the output result indicates that there is a vascular stenosis area that meets the condition (locally magnified as shown). Figure 3 In Figure (b), indicated by the red arrow, the location is at scanning station 1 (i.e., the head and neck), and its spatial position is a cuboid formed by points [50, -20, -20] and [62, -12, -10] as diagonal vertices. Therefore, the MRI scanning table was then automatically moved using this location information to ensure that this cuboid space was within the effective scanning range, and localized black-blood imaging was performed within a cuboid area with a volume twice the size of the body center. Figure 3 (Figure (c)). After 48 hours, the target underwent ferumoxytol-enhanced local bright blood imaging at scanning station 1. Following image registration and spatial location information transfer, multi-sequence local inflammatory imaging was performed within a spatial range consistent with the local dark blood imaging. The results of some sections are shown in Figure (c). Figure 3 As shown in Figures (d)-(f), all checks are now complete.

[0067] Based on preclinical and clinical trial results, this invention achieves a ferumoxytol-enhanced whole-body vascular multimodal magnetic resonance imaging method within a clinically acceptable scan time range by designing the temporal sequence and scanning spatial range of the three parts: bright blood imaging, dark blood imaging, and inflammation imaging, and by reusing the bright blood imaging information, which has the shortest scan time. Compared with existing technologies, this method provides more systematic and comprehensive vascular information while better balancing scan time.

[0068] To provide a more complete and thorough explanation of this method, some necessary details of the scheme are given below.

[0069] Below, we will supplement some necessary details or background information to more completely and fully explain this method.

[0070] Regarding sequence selection for the three imaging modalities, in step S110, during whole-body vascular bright blood imaging, the selectable sequence type is a T1-weighted sequence. This is to utilize the property of iron to shorten the T1 relaxation time of blood to achieve a bright blood effect. In step S140, during local dark blood imaging, the selectable sequences are clinically common dark blood sequences and their combinations, such as T1-VISTA, T2-VISTA, T2*-weighted sequences, and T2-weighted sequences (including but not limited to half-Fourier single-shot fast spin echo sequences with no magnetization preparation pulse). The principle behind these sequences achieving the dark blood effect is the use of the flow void effect of blood, the suppression of blood signals by inversion recovery sequences, or the property of iron to shorten the T2 / T2* ratio of blood. The selectable sequences for local inflammation imaging deserve special mention because there is currently no definitive gold standard protocol for inflammation imaging in clinical practice. The inflammation imaging referred to here is broad, meaning that any MRI sequence that reflects the iron uptake and distribution by monocytes and macrophages (such as macrophages) is selectable. This may lead to overlap in sequence selection between local inflammation imaging and black blood imaging, but the information they reflect regarding the progression of vascular disease is significantly different. This is because, after a certain time delay, iron-phagocytic mononuclear phages accumulate in the inflammatory area and reach a certain concentration before being detected by MRI. Therefore, local inflammation imaging requires a longer time and reflects more information about the inflammatory state. Common inflammation imaging sequences include T1-VISTA, T2-VISTA, quantitative T2*mapping or quantitative T2 mapping sequences, and combinations thereof.

[0071] As mentioned above, the imaging time points for the three modalities are within a variable range. This is because iron, as a blood pool contrast agent, has a blood half-life of up to tens of hours (the specific value depends on the concentration). Furthermore, considering the different objective conditions of different targets, the optimal imaging time point may differ for each imaging modality. However, it has been clearly stated that for whole-body vascular bright-blood imaging and local dark-blood imaging, based on clinical results, it is preferable to perform the imaging immediately after injection, as the blood drug concentration is highest at this time, enabling sufficient enhancement or inhibition of the blood signal (the effect varies depending on the sequence). Local inflammatory imaging should be performed within 24-48 hours after contrast agent injection. This is because it takes at least 24 hours for mononuclear macrophages that engulf iron to achieve a localized aggregation abundance detectable by MRI, while the blood drug concentration is still sufficient for bright-blood imaging of the vascular lumen within 48 hours.

[0072] A stenotic vessel that meets certain criteria is defined as a stenosis that is considered sufficiently severe for a specific clinical purpose, according to a certain industry consensus. For example, it can be defined as a percentage of stenosis in diameter or cross-sectional area. The threshold and grading of stenosis are adjusted according to different clinical purposes.

[0073] The area to be scanned is a spatial range no smaller than the narrow region. Generally, a spatial range at least twice the volume of the narrow region is selected for scanning to ensure that the blood vessel lumen and blood vessel wall of the narrow segment are fully included.

[0074] This method reuses local bright blood imaging in localized inflammation imaging. Besides its use for image registration to determine the scan range, another advantage is that it improves the availability / success rate and interpretability of single-scan images in this step. To better quantify the results of localized inflammation imaging, a crucial requirement is to clearly define the regions where the vascular lumen and vessel wall are located in the inflammation imaging images. However, significant signal loss may occur in both quantitative T2 and / or quantitative T2* inflammation imaging sequences (e.g., when the echo time parameter is set to a long value or the macrophage aggregation concentration is high), especially in quantitative T2* sequences due to the additional influence of magnetic field inhomogeneity, where signal loss may be more severe. Although such significant signal loss can be addressed by rescanning after adjusting the scanning program and sequence parameters, this undoubtedly wastes time and image data. In this invention, the local bright blood imaging in this step can be registered with the previous whole-body bright blood imaging and localized dark blood imaging to achieve more accurate differentiation of vascular lumen and vessel wall regions / contours, thereby improving the availability / success rate of single-scan images.

[0075] Example 2

[0076] Please see Figure 4 , Figure 4This is a schematic diagram of the structure of an iron-enhanced whole-body vascular multimodal magnetic resonance imaging system disclosed in an embodiment of the present invention. This system can achieve whole-body vascular imaging and specifically includes:

[0077] The bright blood imaging acquisition module is used to acquire whole-body bright blood images of blood vessels from head to toe, divided into multiple scanning stations and enhanced with iron.

[0078] The vascular stenosis area localization module is used to automatically locate vascular stenosis throughout the body and quantify its degree of stenosis based on vascular structure information and spatial location information in whole-body vascular bright blood imaging, and output the scanning station and location range information of the vascular stenosis area.

[0079] The vascular stenosis region identification module is used to determine whether there is a vascular stenosis region that meets the conditions; if it exists, proceed to the next step; otherwise, the process ends.

[0080] The black-blood imaging acquisition module guides the MRI system examination table to move according to the spatial location information of the stenotic area of ​​the blood vessel, so that the stenotic area is included in the effective scanning range and local black-blood imaging is performed with a spatial range not less than that of the stenotic area.

[0081] The local bright blood imaging module is used to perform local bright blood imaging on scanning stations with vascular stenosis areas at intervals, thereby obtaining images of the vascular lumen structure.

[0082] The inflammation imaging acquisition module is used to register the local bright blood imaging from the scanning station with the whole-body vascular bright blood imaging to complete the information transmission of the vascular stenosis area and to perform local inflammation imaging.

[0083] In one optional implementation, the iron-enhanced whole-body vascular multimodal magnetic resonance imaging method includes: a) acquiring iron-enhanced whole-body vascular bright blood imaging; b) automatically locating whole-body vascular stenosis and quantifying its degree of stenosis, and outputting the scanning station and location range information of the stenotic region; c) determining whether there is a vascular stenosis region that meets the conditions; if so, proceed to the next step, otherwise end the process; d) acquiring local dark blood imaging for the vascular stenosis region that meets the conditions; e) performing local bright blood imaging on the scanning station with the vascular stenosis region at intervals to obtain vascular lumen structure images; f) registering the local bright blood imaging of the scanning station with the whole-body vascular bright blood imaging to complete the information transmission of the vascular stenosis region, and performing local inflammation imaging.

[0084] Please see Figure 5 , Figure 5 This is a schematic diagram of the structure of an iron-enhanced whole-body vascular multimodal magnetic resonance imaging device disclosed in an embodiment of the present invention. Figure 5The described device can be applied to medical imaging, such as for whole-body vascular imaging, and the embodiments of the present invention are not limited thereto.

[0085] like Figure 5 As shown, the device may include a processor and a memory, the memory storing computer instructions, and the processor executing the computer instructions stored in the memory. When the computer instructions are executed by the processor, the electronic device implements the steps of the method described in the above embodiments and achieves the same technical effect as the above method.

[0086] The memory may include computer system readable media in the form of volatile memory, such as random access memory (RAM) and / or cache memory. The device may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, the memory may be used to read and write non-removable, non-volatile magnetic media (commonly referred to as a "hard disk drive"). A program / utility having a set (at least one) of program modules may be stored in, for example, memory. Such program modules include, but are not limited to, an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include an implementation of a network environment. The program modules typically perform the functions and / or methods described in the embodiments of the present invention.

[0087] The processor executes various functional applications and data processing by running programs stored in memory, such as the method provided in Embodiment 1 of the present invention.

[0088] Example 4

[0089] Embodiment 4 of the present invention also provides a computer-readable storage medium storing a computer program thereon. When the program is executed by a processor, it implements the steps of the method described in the above embodiments and achieves the same technical effect as the above method.

[0090] The computer storage medium of this invention can be any combination of one or more computer-readable media. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0091] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0092] Program code contained on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0093] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof. Programming languages ​​include object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0094] Of course, the computer-executable instructions provided in the embodiments of the present invention are not limited to the above-described method operations, but can also perform related operations in the methods provided in any embodiment of the present invention.

[0095] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for iron-enhanced whole-body vascular multimodal magnetic resonance imaging, characterized in that, Includes the following steps: After the target was divided into multiple scanning stations from head to toe, iron-enhanced whole-body vascular bright blood imaging was performed. Based on the vascular structure and spatial location information in whole-body vascular bright blood imaging, the system automatically locates and quantifies the degree of stenosis in whole-body blood vessels, and outputs the scanning station and location range information of the stenotic area. Determine if a vascular stenosis area exists that meets the criteria; if it does, proceed to the next step; otherwise, end the process. For vascular stenosis areas that meet the criteria, the MRI system examination table is moved according to the spatial location information of the vascular stenosis area, so that the vascular stenosis area is included in the effective scanning range, and local black blood imaging is performed with a spatial range not less than that of the vascular stenosis area. During the interval period, local bright blood imaging is performed on the scanning station where there is vascular stenosis, thereby obtaining images of the vascular lumen structure; The local bright blood imaging of the scanning station is registered with the whole-body vascular bright blood imaging to complete the information transmission of the vascular stenosis area and to perform local inflammation imaging.

2. The iron-enhanced whole-body vascular multimodal magnetic resonance imaging method according to claim 1, characterized in that: The adjacent scanning stations among the plurality of scanning stations maintain a moderate spatial overlap for registration, stitching, and subsequent analysis of whole-body images.

3. The iron-enhanced whole-body vascular multimodal magnetic resonance imaging method according to claim 2, characterized in that: The adjacent scanning stations among the plurality of scanning stations maintain a spatial overlap of 7-15 cm on the z-axis of the MRI system's world coordinate system.

4. The iron-enhanced whole-body vascular multimodal magnetic resonance imaging method according to claim 1, characterized in that: The location range information includes the scanning station number where the vascular stenosis area is located and the spatial range in the MRI system's world coordinate system.

5. The iron-enhanced whole-body vascular multimodal magnetic resonance imaging method according to claim 1, characterized in that: The iron supplement is ferumoxytol or MoldayION.

6. The iron-enhanced whole-body vascular multimodal magnetic resonance imaging method according to claim 1, characterized in that: During the interval period, based on the scanning station number of the vascular stenosis area that meets the output conditions, local bright blood imaging is performed on the scanning station corresponding to the scanning station number.

7. The iron-enhanced whole-body vascular multimodal magnetic resonance imaging method according to claim 1, characterized in that: The vascular cavity structure image is a subset of whole-body vascular bright blood imaging.

8. An iron-enhanced whole-body vascular multimodal magnetic resonance imaging system, characterized in that, include: The whole-body bright blood imaging acquisition module is used to acquire whole-body bright blood images of blood vessels from head to toe, divided into multiple scanning stations and enhanced with iron. The vascular stenosis area localization module is used to automatically locate vascular stenosis throughout the body and quantify its degree of stenosis based on vascular structure information and spatial location information in whole-body vascular bright blood imaging, and output the scanning station and location range information of the vascular stenosis area. The vascular stenosis region identification module is used to determine whether there is a vascular stenosis region that meets the conditions; if it exists, proceed to the next step; otherwise, the process ends. The black-blood imaging acquisition module guides the MRI system examination table to move according to the spatial location information of the stenotic area of ​​the blood vessel, so that the stenotic area is included in the effective scanning range and local black-blood imaging is performed with a spatial range not less than that of the stenotic area. The local bright blood imaging module is used to perform local bright blood imaging on scanning stations with vascular stenosis areas at intervals, thereby obtaining images of the vascular lumen structure. The inflammation imaging acquisition module is used to register the local bright blood imaging from the scanning station with the whole-body vascular bright blood imaging to complete the information transmission of the vascular stenosis area and to perform local inflammation imaging.

9. An iron-enhanced whole-body vascular multimodal magnetic resonance imaging device, characterized in that, The device includes a processor and a memory, the memory storing computer instructions, the processor executing the computer instructions stored in the memory, and when the computer instructions are executed by the processor, the device implements the steps of the iron-enhanced whole-body vascular multimodal magnetic resonance imaging method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the iron-enhanced whole-body vascular multimodal magnetic resonance imaging method as described in any one of claims 1 to 7.

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