A magnetic resonance device scan parameter correction method, ablation device and ablation system

Abstract

The application provides a magnetic resonance equipment scanning parameter correction method, device and system, and the method comprises the following steps: periodically performing fast magnetic resonance imaging on a target region, and obtaining a set of continuous magnetic resonance images in each period; for each set of continuous magnetic resonance images, establishing a three-dimensional temperature map according to a phase diagram in the magnetic resonance images, and establishing a three-dimensional amplitude diagram according to an amplitude diagram in the magnetic resonance images; for each period, generating new scanning parameters according to the registration relationship between the three-dimensional amplitude diagrams of the current period and the previous period, and the new scanning parameters are used for fast magnetic resonance imaging in the next period. According to the application, a set of continuous magnetic resonance images are obtained through fast magnetic resonance imaging, and are used for reconstructing a three-dimensional temperature map and a three-dimensional amplitude diagram, so that the three-dimensional structure and the temperature state can be conveniently observed; meanwhile, the current scanning parameters are corrected according to the registration relationship between the three-dimensional amplitude diagrams of the current period and the previous period, and it is not necessary to perform positioning sequence scanning again, so that the time of the laser interstitial thermotherapy process is saved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a magnetic resonance device scanning parameter correction method, an ablation device and an ablation system. BACKGROUND

[0002] MR guided laser interstitial thermotherapy (MRgLITT) is a method of using laser to destroy target lesions, which uses an optical fiber to guide light energy into the target tissue, as the irradiation time increases, the temperature of the target tissue rises, and eventually reaches the temperature required for thermal ablation, thereby eliminating the lesion, and in the operation, the temperature state of the target tissue is monitored by using a magnetic resonance device, so as to ablate the target area as much as possible while avoiding ablation of normal tissue. MR guided laser interstitial thermotherapy has the advantages of micro-invasion, low risk and fast recovery, and provides a new treatment option for various diseases (such as brain tumors, epilepsy, liver, spleen, prostate tumors, etc.).

[0003] Since the light-emitting part of the optical fiber tip emits laser light to the target tissue in a direction substantially perpendicular to the optical fiber, in order to better observe the ablation state, the current commonly adopted solution is to set the scanning parameters of the magnetic resonance device so that the magnetic resonance device acquires magnetic resonance images at several mutually parallel sections (for example, 3 sections) perpendicular to the direction of the optical fiber and passing through the target tissue, for generating a temperature map. The reason for acquiring magnetic resonance images at only several sections passing through the target area is to speed up the update frequency of the temperature state, to meet the real-time requirement of temperature monitoring.

[0004] The problem faced by the prior art is that when the patient moves, the spatial positions of the target tissue and the optical fiber change, and a larger range of positioning sequence scanning (for example, in one application example, it takes about 5 minutes) needs to be performed again to re-determine the positions of the target area and the optical fiber, and to determine new scanning parameters according to the positions of the target area and the optical fiber. The above-mentioned positioning sequence scanning and re-determination of scanning parameters process takes a long time and needs to interrupt the ablation process.

[0005] To overcome the above-mentioned defects, the present application provides a magnetic resonance device scanning parameter correction method, device and system. SUMMARY

[0006] The present application provides a magnetic resonance device scanning parameter correction method, device and system to solve the defects in the prior art, improve the scanning efficiency of the magnetic resonance image, and shorten the operation time.

[0007] The present application provides a magnetic resonance device scanning parameter correction method, comprising:

[0008] periodically performing fast magnetic resonance imaging on the target region, and obtaining a set of continuous magnetic resonance images in each period;

[0009] for each set of continuous magnetic resonance images, establishing a three-dimensional temperature map according to a phase map in the magnetic resonance images, and establishing a three-dimensional amplitude map according to an amplitude map in the magnetic resonance images;

[0010] for each period, generating a new scanning parameter according to a registration relationship of the three-dimensional amplitude maps of the current period and the reference period, for the fast magnetic resonance imaging in the next period.

[0011] According to the magnetic resonance device scanning parameter correction method provided by the application, periodically performing fast magnetic resonance imaging on the target region, and obtaining a set of continuous magnetic resonance images in each period, further comprises:

[0012] acquiring a positioning sequence scanning image, establishing a positioning three-dimensional structure map according to the positioning sequence scanning image, and registering the positioning three-dimensional structure map with a preoperative three-dimensional image, so as to determine the position of the target region; wherein the preoperative three-dimensional image has the target region outlined or automatically segmented;

[0013] determining the initial scanning parameter according to the position of the target region, or determining the initial scanning parameter according to a user input instruction.

[0014] According to the magnetic resonance device scanning parameter correction method provided by the application, determining the initial scanning parameter according to the position of the target region, further comprises:

[0015] determining the initial scanning direction as the direction of the thinnest sandwich according to the shape of the target region; wherein the thinnest sandwich refers to two parallel planes sandwiching the target region range, so that the two planes have the minimum distance.

[0016] According to the magnetic resonance device scanning parameter correction method provided by the application, periodically performing fast magnetic resonance imaging on the target region, and obtaining a set of continuous magnetic resonance images in each period, comprises:

[0017] determining a target region to be sampled in the current period according to a preset magnetic resonance downsampling rule;

[0018] performing magnetic resonance scanning on the target region to obtain a magnetic resonance image of the target region;

[0019] obtaining the continuous magnetic resonance images in the current period according to the magnetic resonance image of the target region.

[0020] According to the magnetic resonance device scanning parameter correction method provided by the application, the preset magnetic resonance downsampling rule is interlayer downsampling and / or intra-layer downsampling.

[0021] The application provides a method for correcting scanning parameters of a magnetic resonance device, which comprises the following steps of: obtaining continuous magnetic resonance images of a target region according to a magnetic resonance image of the target region in a current period, wherein the method comprises the following steps of:

[0022] The continuous magnetic resonance images of the target region are obtained by interpolation according to the magnetic resonance image of the target region; or,

[0023] The continuous magnetic resonance images of the target region are obtained by interpolation according to the magnetic resonance image of the target region and the magnetic resonance image of the target region in a complementary period.

[0024] The application provides a method for correcting scanning parameters of a magnetic resonance device, which comprises the following steps of: periodically performing fast magnetic resonance imaging on a target region, and obtaining a group of continuous magnetic resonance images in each period, wherein the method comprises the following steps of:

[0025] The target region is scanned by a magnetic resonance fast imaging sequence in each period;

[0026] The magnetic resonance images in the current period are corrected by using a reference period, and corrected magnetic resonance images are obtained.

[0027] The application provides a method for correcting scanning parameters of a magnetic resonance device, wherein the magnetic resonance image in the reference period is a positioning sequence scanning image obtained by scanning a reference region in advance, and the reference region covers the target region.

[0028] The application provides a method for correcting scanning parameters of a magnetic resonance device, wherein the magnetic resonance fast imaging sequence is a gradient echo sequence, and the positioning sequence is a spin echo sequence.

[0029] The application provides a method for correcting scanning parameters of a magnetic resonance device, wherein the reference period is any corrected period, and the magnetic resonance images in the current period are corrected by using the reference period, and the method comprises the following steps of:

[0030] Distortion correction information is obtained according to a first position of a target structure in a magnetic resonance image in a reference period and a second position of the target structure in a magnetic resonance image in a reference period, wherein the reference period is a positioning sequence scanning image obtained by scanning a reference region in advance, and the reference region covers the target region;

[0031] The magnetic resonance images in the current period are corrected according to the distortion correction information.

[0032] The application provides a method for correcting scanning parameters of a magnetic resonance device, wherein for each group of continuous magnetic resonance images, a three-dimensional temperature map is established according to a phase map in the magnetic resonance image, and a three-dimensional amplitude map is established according to an amplitude map in the magnetic resonance image, and the method further comprises the following steps of:

[0033] The background region in the current period is compared with the background region in the last period;

[0034] If the change of the accumulated gray value of the background region does not exceed the preset threshold, then the next cycle is entered, and the step of periodically performing fast magnetic resonance imaging on the target region is executed;

[0035] If the change of the accumulated gray value of the background region exceeds the preset threshold, the step of generating new scanning parameters according to the registration relationship of the three-dimensional amplitude maps of the current cycle and the reference cycle is jumped to.

[0036] According to the magnetic resonance device scanning parameter correction method provided by the application, the new scanning parameters generated according to the registration relationship of the three-dimensional amplitude maps of the current cycle and the reference cycle include:

[0037] The background regions of the three-dimensional amplitude maps of the current cycle and the reference cycle are registered, and the new scanning parameters are obtained by correcting the scanning parameters of the reference cycle based on the registration relationship.

[0038] According to the magnetic resonance device scanning parameter correction method provided by the application, for each set of continuous magnetic resonance images, a three-dimensional temperature map is established according to the phase map in the magnetic resonance image, and a three-dimensional amplitude map is established according to the amplitude map in the magnetic resonance image, and the method further includes:

[0039] Determine whether the three-dimensional amplitude map of the current cycle contains the target region;

[0040] If the three-dimensional amplitude map of the current cycle completely contains the target region, the next cycle is entered, and the step of periodically performing fast magnetic resonance imaging on the target region is executed;

[0041] If the three-dimensional amplitude map of the current cycle partially contains the target region, the step of generating new scanning parameters according to the registration relationship of the three-dimensional amplitude maps of the current cycle and the reference cycle is jumped to.

[0042] If the three-dimensional amplitude map of the current cycle does not contain the target region at all, the three-dimensional amplitude map of the current cycle is registered with the positioning three-dimensional structure map, and the new scanning parameters are determined according to the registration relationship; wherein the positioning three-dimensional structure map is a three-dimensional amplitude map established according to a positioning sequence scan image.

[0043] According to the magnetic resonance device scanning parameter correction method provided by the application, the new scanning parameters generated according to the registration relationship of the three-dimensional amplitude maps of the current cycle and the reference cycle include:

[0044] If the images of some of the tomographic positions in the three-dimensional amplitude map of the current cycle match the previous cycle, and the images of the remaining tomographic positions do not match the previous cycle, the magnetic resonance image of the current cycle is not used for registration, the three-dimensional amplitude maps of the next cycle and the previous cycle are registered, and the new scanning parameters are obtained by correcting the scanning parameters of the previous cycle based on the registration relationship.

[0045] The application provides a method for correcting scan parameters of a magnetic resonance device, and the new scan parameters are generated according to the registration relationship between a three-dimensional amplitude map of a current period and a reference period, and the method comprises the following steps:

[0046] In the three-dimensional amplitude map of the current period, the images of part of the tomographic positions are matched with those of the last period, and the images of the remaining tomographic positions are not matched with those of the last period, and in the case that the images of the remaining tomographic positions are not matched with those of the last period, the scan parameters of the last period are corrected to obtain the new scan parameters according to the registration relationship between the images of the remaining tomographic positions and those of the last period.

[0047] The application further provides an ablation device, which comprises a host computer, and the host computer stores executable instructions, and the executable instructions are executed to implement the magnetic resonance device parameter correction method of any one of the preceding aspects, and the scan parameters of the magnetic resonance device are corrected. The ablation device can use various energies, such as laser, confocal ultrasound, radio frequency and the like.

[0048] The application further provides a magnetic resonance guided laser ablation system, which comprises a magnetic resonance device and the laser ablation device described above.

[0049] The magnetic resonance device scan parameter correction method, device and system provided by the application have one or more of the following beneficial effects:

[0050] 1. The continuous magnetic resonance images are acquired by the fast magnetic resonance, and the three-dimensional temperature map is reconstructed, so that the temperature state of each position is convenient for a user, the temperature monitoring is more comprehensive, and the subsequent ablation state evaluation is more accurate;

[0051] 2. The movement parameters of the patient are conveniently determined based on the registration of the three-dimensional amplitude map of the current period and the reference period, and the scan parameter correction is performed accordingly, so that it is unnecessary to reposition the sequence scanning, the ablation (for example, laser, confocal ultrasound and the like) process is avoided, and the operation time is shortened;

[0052] 3. The patient movement is quickly determined based on the background region judgment, and it is unnecessary to perform a complex registration process each time;

[0053] 4. Since the three-dimensional temperature map and the three-dimensional amplitude map are reconstructed, in the case that the three target regions do not exceed the current magnetic resonance scanning range, it is unnecessary to adjust the scan parameters or reposition the sequence scanning, and the operation efficiency is improved;

[0054] 5. In the case that the patient movement is large, the new scan parameters are determined by registering the three-dimensional amplitude map of the current period with the three-dimensional amplitude map established based on the positioning sequence scanning, and it is unnecessary to reposition the sequence scanning, and the operation efficiency is improved;

[0055] 6. The magnetic resonance image is quickly obtained by inter-layer down-sampling / intra-layer down-sampling, and the continuous magnetic resonance image is obtained by a "repairing" method, the imaging cycle is shortened, and the real-time requirement of monitoring temperature during ablation (such as laser, confocal ultrasound, etc.) is met;

[0056] 7. The target area is scanned by a magnetic resonance fast imaging sequence, and the obtained magnetic resonance image is corrected by using a reference cycle to obtain a continuous magnetic resonance image, the imaging cycle is shortened, and the real-time requirement of monitoring temperature during ablation (such as laser, confocal ultrasound, etc.) is met. BRIEF DESCRIPTION OF DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0058] Figure 1 It is a flowchart of a magnetic resonance device scanning parameter correction method provided by the present application;

[0059] Figure 2 It is a schematic diagram of a three-dimensional amplitude map obtained by acquisition and processing when the patient moves;

[0060] Figure 3 It is a program flowchart corresponding to a preferred embodiment of a magnetic resonance device scanning parameter correction method provided by the present application;

[0061] Figure 4 It is a structural schematic diagram of a laser ablation device provided by the present application;

[0062] Figure 5 It is a structural schematic diagram of a laser ablation device provided by the present application. DETAILED DESCRIPTION

[0063] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are some embodiments of the present application, but not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0064] The following will describe a magnetic resonance device scanning parameter correction method, device and system provided by the present application in combination with Figures 1-5 The following will describe a magnetic resonance device scanning parameter correction method, device and system provided by the present application in combination with

[0065] Figure 1 is a correction method of scanning parameters of a magnetic resonance device provided by the present application, which is used for laser interstitial thermotherapy guided by magnetic resonance. The execution subject of the method is a laser ablation device host, as shown in the figure. The method comprises the following steps. Figure 1

[0066] S11. Periodically perform fast magnetic resonance imaging on the target region, and obtain a set of continuous magnetic resonance images per period;

[0067] Specifically, during the intraoperative ablation process, we only focus on the temperature state of the target region and the tissue near the target region, therefore, performing a limited-range magnetic resonance scan on the target region (i.e., covering at least the target region) can shorten the magnetic resonance scan time and accelerate the update frequency of the temperature state. The current scan parameters are set so that the magnetic resonance device can collect a set of continuous magnetic resonance images covering the target region in the current scanning period according to the current scan parameters. Here, continuous means that the layers in a set of magnetic resonance images are continuously adjacent, and there is no "missing area" between layers.

[0068] Fast magnetic resonance imaging refers to an imaging method that can shorten the magnetic resonance imaging time, for example, a magnetic resonance scanning method that adopts means such as shortening the repetition time TR, collecting fewer phase encoding lines, using parallel acquisition technology, using a planar echo imaging sequence, using a gradient echo imaging sequence, using EPI, PRESTO, b-SSFP imaging sequence, etc. Fast magnetic resonance imaging can obtain magnetic resonance image data with higher resolution and more layers, which facilitates the establishment of a three-dimensional temperature map, and can also include more temperature data while meeting the real-time requirements of intraoperative magnetic resonance temperature monitoring. For example, in the prior art, 3 parallel tomographic magnetic resonance images are collected per period, the data resolution of each layer (i.e., the layer thickness of each layer) is 3 mm, and the data collection time per period is about 4 s. In an embodiment of the present application, a fast magnetic resonance sequence is used to scan, 20 continuous magnetic resonance images are collected per period, the data resolution of each layer is 1 mm, and the data collection time per period is 5-6 s. The data resolution is higher, and the real-time requirements can still be met. More specifically, the fast magnetic resonance imaging in the present application refers to a magnetic resonance imaging method with an imaging period of less than 6 s.

[0069] S12. For each set of continuous magnetic resonance images, a three-dimensional temperature map is established according to the phase map in the magnetic resonance image, and a three-dimensional amplitude map is established according to the amplitude map in the magnetic resonance image;

[0070] ​The three-dimensional temperature map is established according to the continuous thin-layer magnetic resonance images obtained by the rapid magnetic resonance scanning, the image signal-to-noise ratio is improved, the temperature condition is observed in the three-dimensional space, and the ablation process is better guided and the ablation state is better evaluated. Specifically, each magnetic resonance image includes an amplitude graph and a phase graph, wherein the phase graph can be used to generate a two-dimensional temperature map at a corresponding acquisition position (a cross section), and each phase graph in a group of magnetic resonance images can be used to establish a three-dimensional temperature map corresponding to the period. The amplitude graph represents the structural information at the corresponding acquisition position (cross section), and a three-dimensional amplitude graph is obtained by reconstructing each amplitude graph in the current period. The three-dimensional amplitude graph facilitates multi-angle observation of the structural information in space, determination of whether the current magnetic resonance scanning range covers the target region, determination of the ablation state of the target region, and the like.

[0071] S13, generating a new scanning parameter according to the registration relationship between the three-dimensional amplitude graphs of the current period and the reference period, for the next period of rapid magnetic resonance imaging.

[0072] It can be understood that, in the case of unchanged scanning parameters, the scanning range of the magnetic resonance device in the real space in one period is certain. When the patient moves, the range of the body part of the patient scanned by the magnetic resonance device changes, and it is possible that the target region is not scanned, or the imaging field of view changes, affecting the observation effect.

[0073] Therefore, the three-dimensional amplitude graph of the current period is registered with the three-dimensional amplitude graph of the reference period. If direct matching is possible without conversion, it indicates that the patient has not moved, and the current scanning parameter (i.e., the correction amplitude is 0) can be maintained for the next period of magnetic resonance imaging. If conversion is required for matching, it indicates that the patient has moved. At this time, the overlapping part after matching is the range of the body part scanned by the magnetic resonance device before and after the movement, and the obtained registration relationship corresponds to the "movement parameter" of the patient. According to the registration relationship, the current scanning parameter can be calibrated and updated. After the current scanning parameter is corrected, a new scanning parameter can be obtained. The host sends the new scanning parameter to the magnetic resonance device, so that the magnetic resonance device performs magnetic resonance scanning according to the new scanning parameter (i.e., the "current scanning parameter" of the next period) in the next scanning period, so that the target region appears at a suitable position in the magnetic resonance scanning range (for example, so that the target region is located in the central scanning range), facilitating monitoring of the state of the target region.

[0074] It can be understood that in the prior art, the heating effect of the optical fiber can be monitored only in several isolated two-dimensional sections perpendicular to the direction of the optical fiber, and once the patient moves, the positioning sequence scanning needs to be performed again, the scanning parameters need to be determined again, and the two-dimensional magnetic resonance image at the section perpendicular to the direction of the optical fiber is obtained. Since the three-dimensional temperature map is acquired and reconstructed in the present application, the temperature data can be observed from any angle, direction and section, and when the patient moves, the magnetic resonance scanning range can be corrected conveniently and quickly according to the registration relationship of each three-dimensional amplitude map, without the need for positioning sequence scanning and without the need for interrupting the normal laser ablation process.

[0075] In the present embodiment, more data is acquired by fast magnetic resonance imaging under the condition of meeting the real-time requirement of temperature monitoring, a three-dimensional temperature map is reconstructed according to each phase map in each group of continuous magnetic resonance images, more comprehensive information is provided for the laser ablation process, a three-dimensional amplitude map is reconstructed according to the amplitude map in each group of magnetic resonance images, the three-dimensional structure is observed conveniently, and the current scanning parameter is corrected efficiently and accurately according to the registration relationship between the current three-dimensional amplitude map and the previous three-dimensional amplitude map, so that the situation that the image quality is poor due to the movement of the patient and the positioning sequence scanning needs to be performed again is avoided, and the operation efficiency of laser interstitial thermotherapy is improved.

[0076] Further, the three-dimensional temperature map and the three-dimensional amplitude map can be displayed in fusion, or the three-dimensional temperature map and the preoperative three-dimensional image are displayed in fusion, so that the user can observe the temperature state at each position intuitively.

[0077] Based on any one of the embodiments, in one embodiment, before S11, further comprising:

[0078] The positioning sequence scanning image is acquired, a positioning three-dimensional structure map is established according to the positioning sequence scanning image, and the positioning three-dimensional structure map is registered with the preoperative three-dimensional image, so as to determine the position of the target region; wherein the target region is outlined or automatically segmented in the preoperative three-dimensional image;

[0079] The initial scanning parameter is determined according to the position of the target region, or the scanning parameter is determined according to the user input instruction.

[0080] Specifically, the position of the target region is determined by a positioning sequence scan, which can be a T1 WI (T1 weighted imaging), a T2 WI (T2 weighted imaging), a DWI (diffusion weighted imaging), a SE (spin echo sequence imaging) scan, etc. Preferably, the imaging mode of the positioning sequence scan image is consistent with that of the preoperative three-dimensional image, so as to improve the registration accuracy of the positioning sequence scan image and the preoperative three-dimensional image. The positioning sequence scan image contains a series of amplitude maps, and a three-dimensional structure map (i.e., a positioning three-dimensional structure map) for positioning the target site can be reconstructed according to the series of amplitude maps. In the positioning three-dimensional structure map, the target site (a human body site to be subjected to ablation operation, such as liver, spleen, prostate, head, etc.) can be observed.

[0081] Since the medical image acquisition has been performed before the operation, the preoperative three-dimensional image has been established, and the target region has been determined by outlining or automatically segmented by a semantic segmentation model, on this basis, the position of the target region in the positioning sequence scan image can be determined by registering the positioning sequence scan image with the preoperative three-dimensional image. Of course, the target region position in the positioning sequence scan image can also be determined by outlining or automatic semantic segmentation based on the positioning sequence scan image.

[0082] According to the position of the target region, the initial scan parameters (for the first stage of intraoperative fast magnetic resonance imaging) can be determined, such as scan direction, scan layer number, scan position, scan resolution, etc. Among them, the scan direction is the direction of the section, the scan layer number is how many layers of magnetic resonance images cover the target region in each scan period (such as 10 layers, 15 layers, 18 layers, etc.), the scan position is the acquisition position of the multi-layer magnetic resonance image, and the scan resolution is the layer thickness of each layer of magnetic resonance image (such as 1 mm, 2 mm, 3 mm, etc.). The initial scan parameters can be automatically set by the application, for example, the scan layer number can be set according to the target region size and the scan resolution; some parameters can also be randomly set (for example, the scan direction is randomly set, since the three-dimensional temperature map and the three-dimensional amplitude map are reconstructed, the user can view the temperature and structure data from any cross section, and the magnetic resonance scan direction does not have to be perpendicular to the fiber direction); the initial scan parameters can also be determined according to the input instruction of the user, for example, the user can select the scan direction that is convenient for observing a certain structure according to the tissue structure that needs to be observed. Further, a certain scan layer number allowance can be set, so that the magnetic resonance scan range covers the target region, which is convenient for monitoring the current ablation boundary and determining whether the normal tissue around the target region is misablated.

[0083] In this embodiment, the position of the target region is accurately determined by reconstructing a three-dimensional structure map for positioning through the positioning sequence scanning and registering with the three-dimensional image before the operation, and then the initial scanning parameters are reasonably set on this basis, which lays a foundation for acquiring the intraoperative fast magnetic resonance imaging and improves the quality of the three-dimensional temperature map.

[0084] Based on any of the embodiments, in one embodiment, before S11, further comprising:

[0085] Acquiring a positioning sequence scanning image, establishing a positioning three-dimensional structure map according to the positioning sequence scanning image, and displaying the positioning three-dimensional structure map through a display device;

[0086] Determining the position of the target region and the initial scanning parameters according to the user input instruction.

[0087] Specifically, the position of the target region is determined through the positioning sequence scanning, which can be T1WI (T1 weighted imaging), T2WI (T2 weighted imaging), DWI (diffusion weighted imaging), SE (spin echo sequence imaging) scanning, etc. The positioning sequence scanning image contains a series of amplitude maps, and a three-dimensional structure map for positioning the target region (i.e., the positioning three-dimensional structure map) can be reconstructed according to the series of amplitude maps. The positioning three-dimensional structure map is displayed in the display device, which facilitates the user to observe and determine the position of the target region and input the initial scanning parameters.

[0088] Based on the above embodiments, in one embodiment, the initial scanning parameters are determined according to the position of the target region, comprising:

[0089] According to the shape of the target region, the direction of the thinnest sandwich layer is taken as the initial scanning direction; wherein the thinnest sandwich layer refers to two parallel planes sandwiching the target region range, so that the two planes have the minimum distance.

[0090] Specifically, the position of the target region represents the actual space occupied by the target region, i.e., the position of the target region contains the shape information of the target region. When two parallel planes sandwich the target region, the two parallel planes constitute the "thinnest sandwich layer" when the distance between them is the smallest. Taking the direction of the thinnest sandwich layer as the scanning direction makes the overall scanning layer thickness of the intraoperative magnetic resonance scanning the smallest and the number of scanning layers the least, accordingly, the magnetic resonance scanning period can be shortened and the update frequency of the three-dimensional temperature map can be accelerated.

[0091] In this embodiment, in the scenario of laser interstitial thermotherapy, the direction of the thinnest sandwich layer is taken as the scanning direction according to the shape of the target region, which optimizes the magnetic resonance scanning parameters and improves the magnetic resonance image acquisition rate and the update frequency of the three-dimensional temperature map.

[0092] Based on any of the embodiments, in one embodiment, the positioning sequence scanning image is an image acquired based on T1WI.

[0093] The positioning sequence scanning can be based on T1 WI imaging, T1 refers to spin-lattice relaxation time (also known as longitudinal relaxation time), and T1 WI refers to T1 weighted imaging, which highlights the longitudinal relaxation difference of the tissue and reduces the influence of other characteristics such as transverse relaxation on the image. Since the T1 value is linearly related to the temperature within a certain temperature range, the T1 WI acquired for the target region can not only position the target region, but also determine the initial temperature of the target region.

[0094] In addition, the positioning sequence scanning image can also use T2 WI imaging, DWI imaging, SE imaging and the like. T2 refers to transverse duration, T2 WI refers to highlighting the transverse relaxation difference of the tissue during imaging, DWI imaging refers to diffusion weighted imaging, and SE imaging refers to spin echo sequence imaging.

[0095] In the embodiment, the target region is accurately positioned by the positioning sequence scanning based on T1 WI, which facilitates the determination of the initial scanning parameters and provides guidance for the ablation of the target region.

[0096] Based on any one of the embodiments, in one embodiment, the fast magnetic resonance sequence scanning image is an image acquired based on gradient echo sequence scanning.

[0097] Specifically, the purpose of using the fast magnetic resonance sequence is to quickly acquire multi-layer magnetic resonance images to generate a three-dimensional temperature map with a resolution meeting the requirements while meeting the real-time requirement of temperature monitoring. Gradient echo sequence scanning (FFE) has higher imaging efficiency than spin echo sequence scanning. The spin echo sequence has a longer spontaneous relaxation time, and the TE (echo time) is longer, such as 10-15 ms, while the echo time of the gradient echo can be as short as 2 ms.

[0098] In addition, the fast magnetic resonance scanning can also be performed by shortening the repetition time TR, acquiring fewer phase encoding lines, using parallel acquisition technology, using gradient echo imaging, using EPI (echo planar imaging), PRESTO (gradient echo translation imaging), and b-SSFP (balanced steady-state free precession imaging) sequence. The following briefly describes these fast magnetic resonance scanning methods:

[0099] Parallel acquisition technology: The parallel acquisition technology uses a multi-channel phased array coil to reduce the acquisition density of the K-space limiting encoding line, accelerate the acquisition speed of the magnetic resonance image, shorten the image acquisition time by 1-16 times, increase the spatial resolution or increase the three-dimensional acquisition imaging range under the premise of constant acquisition time, or increase the number of repeated acquisitions to improve the image quality and reduce artifacts.

[0100] EPI (Echo Planar Imaging): ERI is a special form of gradient echo, which uses a fast reverse gradient to generate a series of gradient echoes in a single relaxation time and phase-encode them separately to fill the corresponding K-space to realize cross-sectional imaging.

[0101] PRESTO (Phase-Encoded Reverse Steady-State Technique): An additional negative gradient pulse is added to the gradient pulse sequence layer, and a positive gradient pulse with the same area is given before the next excitation pulse, so that the gradient echo will be generated in the next TR time, which is equivalent to shifting the echo generated in the current TR time to the next TR time. This technique corrects the gradient echo shift, and the sequence name is called PRESTO sequence.

[0102] b-SSFP (Balanced Steady-State Free Precession): When the longitudinal magnetization vector and the transverse magnetization vector both reach a steady state, this condition is called steady-state free precession. When the TR, TE and flip angle are set reasonably, the various echoes (FID, SE and STE) generated by multiple radio frequency pulses are just combined into one echo, reaching a balanced state. This gradient echo sequence is called balanced steady-state free precession sequence (b-SSFP). The signal acquired by B-SSFP is the combined signal of various echoes, and its information density is higher.

[0103] It should be noted that the magnetic resonance fast imaging can obtain higher resolution and more layers of magnetic resonance images, which is convenient for subsequent establishment of temperature maps, and can also contain more temperature data under the condition of meeting the clinical needs of intraoperative magnetic resonance temperature monitoring. For example, the existing magnetic resonance fast imaging acquires 3 layers of magnetic resonance images per cycle, and the data resolution of each layer (i.e. the layer thickness of each layer) is 3mm, and the data acquisition time per cycle is about 4-6s. If the magnetic resonance fast imaging is used, 20 layers of magnetic resonance images can be obtained per cycle, the data resolution of each layer is 1mm, and the data acquisition time per cycle is 3-6s. The data resolution is higher, and the real-time requirement can still be met.

[0104] In this embodiment, the magnetic resonance image is quickly and high-quality acquired by the specific fast magnetic resonance imaging method described above, which is used to reconstruct a high-resolution three-dimensional temperature map to provide sufficient information support for the laser ablation process.

[0105] Based on any embodiment, in one embodiment, S11 includes:

[0106] According to the preset magnetic resonance down-sampling rule, the target region to be sampled in the current cycle is determined;

[0107] The target region is subjected to magnetic resonance scanning to obtain a magnetic resonance image of the target region;

[0108] According to the magnetic resonance image of the target region, a continuous magnetic resonance image of the current period is obtained.

[0109] Specifically, in the intraoperative ablation process, the magnetic resonance device needs to image the target region to be ablated and the tissue near the target region in order to monitor the temperature state, that is, the continuous magnetic resonance image obtained in each period needs to cover the target region. In order to realize fast magnetic resonance imaging, only part of the region covering the target region is imaged when the magnetic resonance image is collected in a specific period, and then the continuous magnetic resonance image covering the target region is obtained by repairing through the supplementary data. The magnetic resonance downsampling rule is a rule for determining the target region to be scanned in the current period, for example: n layers of magnetic resonance images need to be collected to completely cover the target region, and the preset magnetic resonance downsampling rule is a scanning strategy (i.e. inter-layer downsampling) for which layers are scanned and which layers are not scanned in the current period. More specifically, for example, odd layers are collected in one period, and even layers are collected in the next period, and so on. For another example, 3i+1 layers (i=0, 1, 2, 3…) are collected in one period, 3i+2 layers (i=0, 1, 2, 3…) are collected in the next period, and 3i+3 layers (i=0, 1, 2, 3…) are collected in the next period, and so on. For another example, the preset magnetic resonance downsampling rule can also be combined with the number of layers to be sampled to determine whether to use the first strategy when the number of layers exceeds the threshold or to use the second strategy when the number of layers does not exceed the threshold.

[0110] Wherein, the number of layers threshold can be a preset value for determining whether the number of layers to be scanned of the target region is too large, so as to adopt different inter-layer downsampling strategies, such as 10, 15, 18, etc. The first strategy is a downsampling strategy set for the case that the number of layers to be sampled is too large, and the second strategy is a downsampling strategy set for the case that the number of layers to be sampled is small. Therefore, the interval number of layers of the first strategy is greater than that of the second strategy. For example, in the case of more than 12 layers, it is divided into odd layer collection period and even layer collection period, and in the case of less than 12 layers, each layer is sampled in one period.

[0111] It should be noted that since the target region to be scanned does not change, there will be the same spatial redundancy information between frames, and the inter-layer downsampling acceleration acquisition method can be used to accelerate the acquisition of the magnetic resonance image, for example, using EPI or GRE sequence, and the inter-layer downsampling acceleration acquisition method can improve the image acquisition speed. In this way, only part of the layers of the target region is scanned in each period to accelerate the acquisition of the magnetic resonance image, and then the complete image can be reconstructed using the acquisition data of the current period and the previous period, thereby ensuring the quality of the acquired image, and realizing high spatio-temporal resolution and large range temperature imaging without changing the image quality and scanning time.

[0112] In an optional implementation of the embodiment, the preset magnetic resonance down-sampling rule is to sample odd layers and even layers in a cycle; according to the preset magnetic resonance down-sampling rule, the target region to be sampled in the current cycle is determined, including:

[0113] determining the sampling layer of the previous cycle scanning;

[0114] in the case that the sampling layer of the previous cycle is an odd layer, determining the target layer to be sampled in the current cycle as an even layer;

[0115] in the case that the sampling layer of the previous cycle is an even layer, determining the target layer to be sampled in the current cycle as an odd layer.

[0116] That is to say, the layers sampled in adjacent two cycles are different. In actual application, the sampling layer of the previous cycle scanning can be determined first. If the sampling layer of the previous cycle scanning is an odd layer, the even layer is sampled in the current cycle. If the sampling layer of the previous cycle scanning is an even layer, the odd layer is sampled in the current cycle. For example, the continuous magnetic resonance images covering the target region include 1-10 layers. The layers 1 / 3 / 5 / 7 / 9 are sampled in a cycle, and the layers 2 / 4 / 6 / 8 / 10 are sampled in the next cycle.

[0117] In the embodiment, the region to be sampled is divided into odd layers and even layers for sampling. Odd layers are sampled in one cycle, and even layers are sampled in another cycle. Each cycle only scans part of the layers of the target region, and the layers sampled in adjacent two regions are not repeated, so that the down-sampling is maximized, thereby improving the acquisition speed of the magnetic resonance image sequence to meet the clinical needs of the temperature measurement and ablation calculation based on magnetic resonance.

[0118] In an optional implementation of the embodiment, the preset magnetic resonance down-sampling rule is to sample odd layers and even layers in a cycle; according to the preset magnetic resonance down-sampling rule, the target region to be sampled in the current cycle is determined, including:

[0119] obtaining the number of layers to be sampled of the continuous magnetic resonance images;

[0120] in the case that the number of layers to be sampled exceeds the layer number threshold, determining the target layer to be sampled in the current cycle according to the first strategy;

[0121] in the case that the number of layers to be sampled does not exceed the layer number threshold, determining the target layer to be sampled in the current cycle according to the second strategy.

[0122] Specifically, the layer number threshold value can be a preset value for determining whether the number of layers to be scanned in the target region is too large, so as to adopt different inter-layer down-sampling strategies. For example, the layer number threshold value can be 10, 15, 18, etc. The first strategy is a down-sampling strategy set for the case where the number of layers to be sampled is too large, and the second strategy is a down-sampling strategy set for the case where the number of layers to be sampled is small. Therefore, the interval layer number of the first strategy is greater than that of the second strategy, that is, the first strategy ignores more layers in a period to ensure the scanning speed because the number of layers to be sampled in the target region is too large. For example, the first strategy can sample k-1 layers in different periods, that is, the first layer is sampled in the first period, the 1+k layer is sampled in the next period, the 1+2k layer is sampled in the next period, and so on. The second strategy can sample m-1 layers in different periods, and m is less than k.

[0123] In a specific implementation, the first strategy or the second strategy can be configured based on actual needs. The first strategy or the second strategy can also be to sample odd and even layers in different intervals as described above.

[0124] For example, assume that the target region includes layers 1-12 to be sampled, and the layer number threshold value is 10. In this case, the number of layers to be sampled in the target region exceeds the layer number threshold value. In a period, layers 1 / 4 / 7 / 10 are scanned, in the second period, layers 2 / 5 / 8 / 11 are sampled, and in the third period, layers 3 / 6 / 9 / 12 are acquired. In addition, assume that the layer number threshold value is 15. In this case, the number of layers to be sampled in the target region does not exceed the layer number threshold value. In this case, layers 1 / 3 / 5 / 7 / 9 / 11 can be acquired in a period, and layers 2 / 4 / 6 / 8 / 10 / 12 can be acquired in the next period. That is, when the number of layers to be sampled in the target region exceeds the layer number threshold value, 2 layers are sampled in each period. When the number of layers to be sampled in the target region does not exceed the layer number threshold value, 1 layer is sampled in each period.

[0125] It should be noted that when the number of layers to be sampled exceeds the layer number threshold value, it means that the target region includes a large number of layers to be sampled. In this case, the first strategy can be used to determine the target layer to be sampled in the current period. When the number of layers to be sampled does not exceed the layer number threshold value, it means that the target region includes a small number of layers to be sampled. In this case, the second strategy is used to determine the target layer to be sampled in the current period. For different cases of the target region, different inter-layer down-sampling strategies can be adopted, which can adapt to more application scenarios and improve the applicability and flexibility.

[0126] In an optional implementation of the embodiment, in addition to using the inter-layer down-sampling method to improve the scanning speed, the intra-layer down-sampling method can also be used to further improve the scanning speed to meet the temperature monitoring requirements. The fast magnetic resonance imaging scans by column, and the target region to be sampled in the current period is determined according to a preset magnetic resonance down-sampling rule, including:

[0127] determining, according to a preset inter-layer down-sampling rule, data columns to be sampled in a current period;

[0128] performing magnetic resonance scanning on the data columns to be sampled to obtain a magnetic resonance image sequence of the target region.

[0129] It should be noted that the magnetic resonance fast imaging sequence is column scanning, such as GRE, that is, the magnetic resonance fast imaging sequence scans a column of data in a layer at a time when scanning a layer, and for the column scanning magnetic resonance fast imaging sequence, in addition to the above-mentioned inter-layer down-sampling, intra-layer down-sampling can also be used, that is, only some columns in a layer are collected at a time to improve the scanning speed. In addition, it should be noted that if the magnetic resonance fast imaging sequence is layer scanning, such as EPI, when scanning a layer, a layer is scanned at a time, and intra-layer down-sampling cannot be performed, only inter-layer down-sampling can be performed.

[0130] Specifically, the set intra-layer down-sampling rule is a data column selection strategy for intra-layer data columns, that is, a strategy for which data columns to collect and which data columns not to collect for a layer. For example, the set intra-layer down-sampling rule can be to collect the 2nth column of data in the current period, the 2nth+1 column of data in the next period, and the 2nth+2 column of data in the next period, and so on; or, a 3n, 3n+1, 3n+2 method is used to increase the data collection speed in the layer by 2 or 3 times.

[0131] In actual application, the set inter-layer down-sampling rule is to select part of the column data in a layer for collection, and according to the set intra-layer down-sampling rule, it can be determined which data columns to be collected need to be collected in the current period, and then the magnetic resonance fast imaging sequence is used to scan the data columns to be collected in the target layer to obtain the magnetic resonance image in the current period. In this way, for the target layer, only part of the data columns need to be collected, greatly improving the data collection speed in the layer.

[0132] It should be noted that for the target region (i.e., the ablation region), due to the continuity of temperature in physical space and time, the temperature information of the adjacent positions can be used to estimate the temperature of the unsampled part, thereby ensuring the temperature imaging quality of the target region.

[0133] In specific implementation, the test region can be fully sampled based on the temperature measuring optical fiber to obtain a complete image, and the test region can be down-sampled to obtain a down-sampled image. Then, the complete image obtained by the test is taken as a label, and the down-sampled image is taken as an input of the deep learning model to train the deep learning model to obtain a deep learning model capable of reconstructing a complete image. Subsequently, the data sequence collected by the down-sampling is input into the trained deep learning model to obtain a reconstructed complete image sequence.

[0134] In the embodiments of the present specification, an accelerated acquisition method of inter-layer down-sampling and intra-layer down-sampling can be used, only part of the layers of the target region and part of the data columns in the part of the layers are scanned in each cycle to accelerate the acquisition of the magnetic resonance image, and then the complete image is reconstructed based on the acquired data, and when the image is reconstructed, the spatial information of the target region is invariant and the temperature is continuous in the physical space and time, and the complete image information is reconstructed by using the reconstruction algorithm (for example, interpolation method), so as to ensure the quality of the acquired image, and to realize high spatio-temporal resolution and large range temperature imaging without changing the image quality and scanning time.

[0135] It should be noted that in the actual application scenario, the method of inter-layer down-sampling and intra-layer down-sampling can be used to accelerate the acquisition of the magnetic resonance image, or the method of inter-layer down-sampling or intra-layer down-sampling can be used to accelerate the acquisition of the magnetic resonance image, which is not limited by the embodiments of the present specification. For example, the layers to be sampled of the target region are determined, and each layer to be sampled is regarded as a layer to be scanned in the current cycle, and then for each layer, it is determined which data columns are acquired based on the intra-layer down-sampling rule.

[0136] Based on any one of the embodiments, in an embodiment, the continuous magnetic resonance image of the current cycle is obtained according to the magnetic resonance image of the target region, comprising:

[0137] The continuous magnetic resonance image covering the target region is obtained by interpolation according to the magnetic resonance image of the target region; or,

[0138] The continuous magnetic resonance image covering the target region is obtained according to the magnetic resonance image of the target region and the magnetic resonance image of the complementary cycle thereof.

[0139] Specifically, for example, the preset magnetic resonance down-sampling rule is to sample odd layers and even layers, 1 / 3 / 5 / 7 / 9 layers are acquired in a cycle, 2 / 4 / 6 / 8 / 10 layers are acquired in the next cycle, and the cycle is repeated. In T n The magnetic resonance data of 1 / 3 / 5 / 7 / 9 layers is acquired in the cycle, and the data of 2 / 4 / 6 / 8 / 10 layers is missing. The magnetic resonance image of the even layer can be directly obtained by interpolation according to the magnetic resonance image of the odd layer, for example, the magnetic resonance image of the second layer is filled according to the magnetic resonance images of the first layer and the third layer, the magnetic resonance image of the fourth layer is filled according to the magnetic resonance images of the third layer and the fifth layer, and so on, until the continuous 10-layer magnetic resonance image is obtained, or the missing data can also be filled according to the complementary cycle, for example, the magnetic resonance data of the even layer acquired in T n The magnetic resonance data of 1 / 3 / 5 / 7 / 9 layers acquired in the cycle is combined with the magnetic resonance data of the even layer acquired in T n-1 The magnetic resonance data of the even layer acquired in T nEven-numbered layers of data with periodic missing values, or combined with T n-3 T n-5 Even-numbered layer magnetic resonance imaging data acquired periodically with complementary complementarity are used to complete the T-cell imaging. n Even-numbered layer data missing in the cycle. Data supplemented directly through interpolation steps has limited accuracy. Typically, the structural / temperature state of the patient's target site does not change abruptly. Therefore, data from the complementary cycle of the current cycle can be used as a reference for the current cycle's "interpolation process," further improving repair accuracy. It is understood that the above only illustrates the "repair" process under inter-layer downsampling with a one-layer gap. When there are more layers between the gaps, linear interpolation (or further combined with complementary cycles) can be used to fill in the missing layers. The same method can be used to repair missing data in the case of intra-layer downsampling.

[0140] In this embodiment, continuous magnetic resonance images are obtained by interpolation based on downsampled magnetic resonance images, which improves the efficiency of magnetic resonance image acquisition, meets the requirement of real-time temperature monitoring during laser ablation, and further combines complementary periodic supplementation to fill in missing magnetic resonance data, thereby improving the accuracy of the acquired continuous magnetic resonance images.

[0141] Based on any embodiment, in one embodiment, S11 includes:

[0142] The target area is periodically scanned using rapid magnetic resonance imaging sequences;

[0143] The magnetic resonance image of the current period is corrected using a reference period to obtain a corrected magnetic resonance image.

[0144] Specifically, a fast magnetic resonance imaging sequence can be gradient echo imaging (EPI), and the obtained magnetic resonance image is an EPI sequence. EPI is one of the fastest magnetic resonance imaging methods to date. It is a special form of gradient echo. It uses a fast reverse gradient to generate a series of gradient echoes in a single relaxation time (TR) and encodes them in phase, filling them into the corresponding k-space to achieve cross-sectional imaging.

[0145] Fast magnetic resonance imaging sequences can also be obtained by scanning the target area based on other fast scanning algorithms, such as shortening the repetition time (TR), acquiring fewer phase encoding lines, parallel acquisition technology, gradient echo magnetic resonance pulse sequence (GRE), gradient echo translation imaging (PRESTO), and balanced steady-state free precession imaging (B-SSFP).

[0146] The magnetic resonance fast imaging sequence can usually complete the acquisition of an image in several milliseconds, but information can be lost in the process of fast acquisition to obtain the image, resulting in distortion of the acquired image, and then leading to inaccurate temperature map constructed subsequently, affecting the operation. Taking the EPI as an example, the EPI can complete the acquisition of an image in several milliseconds, so the technology is one of the fast signal acquisition methods, and 10-20 layer images can be quickly scanned (1-4 s) through the fast EPI sequence. However, the EPI sequence generates signals through continuous gradient alternation, without a rephasing pulse to correct the inhomogeneity of the main magnetic field and the error of phase information. With the increase of the EPI factor, the accumulated phase error becomes larger and larger, and the related deformation and artifacts of the image also become more and more serious.

[0147] In actual application, since the position of the patient or the phantom does not change in the process of scanning the target region through the magnetic resonance fast imaging sequence, the spatial information of the tissue on the same scanning plane is unchanged, for example, blood vessels, tumor boundaries, cerebral gyri, etc., that is, the spatial distribution of the target region is basically unchanged, so the present application uses the unchanged spatial position information to correct the distortion generated in the fast scanning process, thereby realizing the fast acquisition of the 3D temperature sequence while not reducing the spatial resolution. Specifically, the magnetic resonance image sequence acquired in the current period can be corrected by using the reference period without spatial distortion (or having completed distortion correction), to obtain the corrected magnetic resonance image in the current period, thereby realizing efficient and accurate three-dimensional temperature detection.

[0148] Based on the previous embodiment, in one embodiment, the reference period is a positioning sequence scanning image obtained by pre-scanning a reference region, and the reference region covers the target region.

[0149] Specifically, the positioning sequence scanning can be T1WI (T1 weighted imaging), T2WI (T2 weighted imaging), DWI (diffusion weighted imaging), SE (spin echo sequence imaging) scanning, etc. The range of the positioning sequence scanning is relatively large. For example, when laser ablation is needed for intracranial tumors, the positioning sequence scanning is performed on the head (reference region) of the patient, and based on the positioning sequence scanning, the position of the tumor (target region) can be determined, so that the fast magnetic resonance imaging of the tumor (target region) in a small range can be performed through the magnetic resonance device during the laser ablation process, and the real-time performance of temperature detection is improved. It can be understood that the imaging range of the above-mentioned positioning sequence scanning image is relatively large, and the imaging accuracy is high. In the present embodiment, the positioning sequence scanning image is also used as the reference period to correct the magnetic resonance fast sequence image acquired during the operation and repair the distortion therein. Specifically, the magnetic resonance image in the current period is corrected by using the reference period to obtain the corrected magnetic resonance image, including:

[0150] acquiring the positioning sequence scanning image obtained by pre-scanning;

[0151] The current period magnetic resonance image is corrected according to the sequence of positioning images to obtain a corrected magnetic resonance image.

[0152] In one possible implementation, third position information of a target structure (such as a blood vessel, a tumor boundary, a brain gyrus, etc.) in the current period magnetic resonance image is determined first, and fourth position information of the target structure in the sequence of positioning images is determined, then a spatial transformation matrix is calculated according to the third position information and the fourth position information, the spatial transformation matrix is used as distortion correction information to correct the current period magnetic resonance image sequence to obtain a corrected magnetic resonance image of the current period.

[0153] In the embodiment, the magnetic resonance image of one period is directly corrected with the sequence of positioning images, which can eliminate the distortion generated in the intraoperative magnetic resonance fast imaging sequence scanning process, and ensure the accuracy of the magnetic resonance image, and further ensure the accuracy of the three-dimensional temperature map constructed subsequently.

[0154] Based on any of the embodiments, in one embodiment, the reference period is any corrected period, and the current period magnetic resonance image is corrected by using the reference period, including:

[0155] The distortion correction information is obtained according to the first position of the target structure in the magnetic resonance image of the reference period and the second position of the target structure in the magnetic resonance image of the reference period, wherein the reference period is the sequence of positioning images scanned in the reference region in advance, and the reference region covers the target region.

[0156] The current period magnetic resonance image is corrected according to the distortion correction information.

[0157] Specifically, in the embodiment, the reference period is a period of scanning the reference region by the sequence of positioning images, and the reference period is a corrected period. In the process of correcting the current period magnetic resonance image, the first position of a target structure (such as a blood vessel, a tumor boundary, a brain gyrus, etc.) in the reference period and the second position of the target structure in the reference period are obtained, and a spatial transformation matrix is calculated according to the first position and the second position, the spatial transformation matrix is used as distortion correction information to correct the current period magnetic resonance image sequence to obtain a corrected magnetic resonance image of the current period.

[0158] In the embodiment, the distortion correction is not directly performed according to the sequence of positioning images, which reduces the difficulty of calculating the distortion correction information and improves the data processing efficiency.

[0159] According to any one of the embodiments, in one embodiment, the magnetic resonance image of the current period is corrected according to the reference period, to obtain a corrected magnetic resonance image of the current period, comprising:

[0160] According to the reference period and the last period of the current period, distortion correction information of the last period is obtained;

[0161] The magnetic resonance image of the current period is corrected using the distortion correction information, to obtain a corrected magnetic resonance image of the current period;

[0162] Based on the magnetic resonance image of the current period and the positioning sequence scan image, the distortion correction information of the current period is determined and stored, wherein the distortion correction information of the current period is used to correct the magnetic resonance image of the next period of the current period.

[0163] It should be noted that the distortion correction information of the last period can be obtained according to the reference period and the last period of the current period, and then the distortion correction information of the last period is directly used to correct the magnetic resonance image of the current period, to obtain a corrected magnetic resonance image of the current period, and then the distortion correction information of the current period is determined for the next period correction. That is, each period is corrected based on the distortion correction information of the previous period.

[0164] As an example, after the reference period, in the second period, since the last period of the second period is the reference period, the magnetic resonance image of the second period can be corrected based on the positioning sequence image of the reference period and the magnetic resonance image of the second period, to obtain a corrected magnetic resonance image sequence of the second period, and the distortion correction information of the second period is obtained and stored; then, in the third period, the distortion correction information of the second period can be directly obtained to correct the magnetic resonance image of the third period, to obtain a corrected magnetic resonance image sequence of the third period, and then based on the positioning sequence scan image of the reference period and the magnetic resonance image of the third period, the distortion correction information of the third period can be calculated and stored; then, in the fourth period, the distortion correction information of the third period can be directly obtained to correct the magnetic resonance image of the fourth period, and so on.

[0165] In the embodiment, each period is corrected based on the distortion correction information of the previous period, which can reduce the accumulation of distortion information of multiple periods and improve the accuracy of correction.

[0166] In one optional implementation of the embodiment, the distortion correction information of the current period is determined and stored according to the magnetic resonance image of the current period and the positioning sequence scan image, comprising:

[0167] determining fifth position information of the target structure in the current cycle magnetic resonance image;

[0168] determining sixth tissue position information of the target structure in the scout sequence scan image;

[0169] calculating a spatial transformation matrix according to the fifth position information and the sixth position information, storing the spatial transformation matrix as the distortion correction information.

[0170] Specifically, the target structure is a tissue with an unchanged position in the patient or the phantom during the scanning, such as a blood vessel, a tumor boundary, a cerebral gyrus, etc.

[0171] It should be noted that the fifth position information of the target structure in the current cycle magnetic resonance image can be determined by image analysis, and the second tissue position information of the target structure in the scout sequence scan image is determined, and then the spatial transformation matrix is calculated according to the first tissue position information and the second tissue position information, and the spatial transformation matrix is the distortion correction information between the first tissue position information and the second tissue position information. In this way, the position information of the unchanged target structure is used to determine the distortion correction information of the current cycle and store it, and the distortion correction information of the current cycle can be directly obtained for correction in the next cycle.

[0172] In an optional embodiment of the present embodiment, in addition to the above-mentioned method of directly correcting the magnetic resonance image of each cycle based on the scout sequence scan image scanned in the reference cycle, or directly correcting each cycle based on the distortion correction information of the last cycle, an optional cycle can be selected as a constant reference cycle to correct the magnetic resonance image of each cycle. Specifically, the magnetic resonance image of the current cycle is corrected according to the reference cycle to obtain the corrected magnetic resonance image of the current cycle, comprising:

[0173] selecting any cycle as a constant reference cycle;

[0174] obtaining constant distortion correction information according to the reference cycle and the constant reference cycle;

[0175] correcting the magnetic resonance image of the current cycle using the constant distortion correction information to obtain the corrected magnetic resonance image of the current cycle.

[0176] It should be noted that any cycle can be selected as a constant reference cycle, and then constant distortion correction information is obtained according to the reference cycle and the constant reference cycle, and then the obtained constant distortion correction information is used to correct the magnetic resonance image of the current cycle to obtain the corrected magnetic resonance image of the current cycle. That is, the magnetic resonance image of each cycle is corrected based on the constant distortion correction information, and the constant distortion correction information can be determined based on any selected cycle, and the correction method is more flexible and can adapt to different scene requirements.

[0177] The specific implementation process of obtaining the constant distortion correction information according to the reference period and the correction reference period can refer to the specific implementation process of determining the distortion correction information of the current period based on the current period magnetic resonance image and the positioning sequence scanning image, which will not be described here.

[0178] In addition, in fast magnetic resonance imaging, if a magnetic resonance fast imaging sequence is used and the patient also moves his head, at this time, it is preferred to correct the magnetic resonance image of the current period according to the reference period to obtain a corrected continuous magnetic resonance image, avoiding the defect that the imaging regions of the current period and the reference period (non-reference period) are inconsistent and the correction error caused by the distortion of the two is large. Alternatively, the distortion images collected in the reference period and the current period are directly registered to obtain distortion correction information, which is used to correct the distortion correction information of the reference period, and then used to correct the magnetic resonance image of the current period. Specifically, the magnetic resonance image of the current period is corrected using the reference period, including:

[0179] Registering the magnetic resonance image of the reference period with the magnetic resonance image of the current period to obtain distortion correction information;

[0180] Correcting the magnetic resonance image of the current period according to the distortion correction information of the reference period and the distortion correction information to obtain a continuous magnetic resonance image of the current period.

[0181] The distortion correction information of the reference period can be obtained according to the foregoing embodiments. In the present embodiment, the imaging distortion is successfully corrected in the case that the magnetic resonance fast imaging sequence exists imaging distortion and the patient also moves his head, which improves the imaging quality and facilitates obtaining more accurate magnetic resonance device scanning parameters.

[0182] Based on any of the embodiments, in one embodiment, after S12, the method further includes:

[0183] Comparing the background region of the current period with that of the previous period;

[0184] If the change of the cumulative gray value of the background region does not exceed the preset threshold, then proceed to the next period and perform S11;

[0185] If the change of the cumulative gray value of the background region exceeds the preset threshold, jump to S13.

[0186] Specifically, the background region refers to a part of the target site (a human body to be operated on, such as liver, spleen, prostate, head, etc.) that does not belong to the target area. The background region can be selected as a part of the target site that is outside the target area and has a certain distance allowance from the target area to avoid the influence of fiber heating and heat conduction. The background region can also be preferably a skull region. The gray scale of the skull region in the magnetic resonance image does not change substantially. Based on the skull judgment, the patient movement can be more accurately judged. The background region will not be heated during the laser ablation process, and the tissue structure will not change. The background region in the current cycle three-dimensional amplitude graph is compared with the background region in the previous cycle three-dimensional amplitude graph. If the difference between the cumulative gray values in the background region of the two is less than or equal to a preset threshold, it indicates that the patient has not moved, and the next cycle of magnetic resonance scanning can be continued according to the current scanning parameter. If the difference is greater than the preset threshold, it indicates that the patient has moved, and S13 needs to be performed to correct the current scanning parameter to determine a new scanning parameter for the next cycle of magnetic resonance scanning.

[0187] The determination method of the above-mentioned background region is, for example, for each cycle of the three-dimensional amplitude graph, the background region of the current cycle is determined again according to the target area range. At this time, the determined background region is more accurate. The determination method of the background region is, for example, the background region is determined in the corresponding region position of the current cycle three-dimensional amplitude graph according to the background region of the previous cycle and the relative region position thereof in the three-dimensional amplitude graph. At this time, the process of determining the background region is more simple and fast, and the comparison between the two cycles of the three-dimensional amplitude graph is facilitated. The determination method of the background region of each cycle is not limited in the present application.

[0188] In the present embodiment, through the above process, it can be quickly and accurately judged whether the patient has moved and whether the current scanning parameter needs to be corrected. The complex registration process does not need to be performed every cycle, and the data processing efficiency is improved.

[0189] Further, in one embodiment, the reference cycle is a cycle before the current cycle. When correcting the scanning parameter, the current cycle is registered with the reference cycle to obtain a registration relationship. The new scanning parameter is obtained by correcting the scanning parameter of the reference cycle using the registration relationship, and is used for the next cycle of magnetic resonance scanning.

[0190] It can be understood that the data amount of the reference cycle is less (the volume is smaller), which reduces the registration calculation amount. In addition, the registration of the current cycle and the reference cycle can also save the "coarse registration" process, and the registration efficiency is improved.

[0191] In another embodiment, the reference period is a period in which a positioning sequence scan is performed, the positioning sequence scan is a large-scale scan performed on the target site, and has a larger imaging range and higher imaging quality. The current period is directly registered with a positioning three-dimensional structure map of the positioning sequence scan period, and new scan parameters are directly determined according to the registration relationship, so that the scan parameters are more accurate and reasonable.

[0192] Based on any embodiment, in one embodiment, S13 comprises:

[0193] The current period is registered with a background region of the three-dimensional amplitude map of the previous period, and new scan parameters are obtained by correcting the scan parameters of the reference period based on the registration relationship.

[0194] Specifically, the registration of the current period with the three-dimensional amplitude map of the previous period is implemented by determining the background region of the three-dimensional amplitude map of the previous period and the background region of the three-dimensional amplitude map of the current period, and then registering the current period with the background region of the three-dimensional amplitude map of the previous period. The background region is a part of the target site that does not belong to the target region. The background region can be selected as a part of the target site that is outside the target region and has a certain distance margin from the target region, so as to avoid the influence of fiber heating and heat conduction on the tissue structure and improve the registration accuracy.

[0195] In this embodiment, registration is only performed based on the background region, and the current scan parameters are corrected based on the registration relationship, thereby avoiding the decrease in registration accuracy caused by changes in the structure of the target region.

[0196] Based on any embodiment, in one embodiment, after S12, the method further comprises:

[0197] Judging whether the three-dimensional amplitude map of the current period contains the target region or not;

[0198] In the case where the three-dimensional amplitude map of the current period completely contains the target region, entering the next period and performing S11;

[0199] In the case where the three-dimensional amplitude map of the current period partially contains the target region, jumping to S13.

[0200] In the case where the three-dimensional amplitude map of the current period does not contain the target region at all, registering the three-dimensional amplitude map of the current period with a positioning three-dimensional structure map, and determining new scan parameters according to the registration relationship; wherein the positioning three-dimensional structure map is a three-dimensional amplitude map established according to a positioning sequence scan image.

[0201] Specifically, the situation of the target region in the three-dimensional amplitude map of the current cycle is judged, for example, the three-dimensional amplitude map is input into a deep learning model to segment the target region, and for another example, the three-dimensional amplitude map is input into a threshold segmentation model to segment the target region according to a gray scale range specific to the target region.

[0202] If the three-dimensional amplitude map of the current cycle completely contains the target region, it indicates that the range of the intraoperative fast magnetic resonance imaging at this time can still cover the target region, and after the three-dimensional temperature map and the three-dimensional structure map are reconstructed, the state of the target region can still be viewed in the three-dimensional space, so that the magnetic resonance scanning of the next cycle can be continued without the need to calibrate the current scanning parameters. Compared with the “patient movement correction” based on two-dimensional magnetic resonance images in the prior art, the present application can still maintain scanning in the case of small patient movement, without affecting the monitoring effect and without interrupting the laser ablation process.

[0203] If the three-dimensional amplitude map of the current cycle partially contains the target region, it indicates that the current magnetic resonance scanning range cannot cover the target region, and the current scanning parameters need to be corrected in step S13.

[0204] If the three-dimensional amplitude map of the current cycle does not contain the target region at all, it indicates that the degree of patient movement is large, and the three-dimensional amplitude map of the current cycle cannot be registered with the three-dimensional amplitude map of the previous cycle (or the registration accuracy is low), so that the movement parameters of the patient cannot be accurately determined based on the registration relationship between the three-dimensional amplitude maps of the current cycle and the previous cycle. Since a wide range of positioning sequence scanning has been performed on the target region before the intraoperative fast magnetic resonance, and a positioning three-dimensional structure map is established based on the positioning sequence scanning image, by registering the three-dimensional amplitude map of the current cycle with the positioning three-dimensional structure map, the initial scanning parameters are calibrated based on the registration relationship, the new scanning parameters can be determined for the magnetic resonance scanning of the next cycle.

[0205] Based on any of the embodiments, in one embodiment, S13 includes:

[0206] In the case where, in the three-dimensional amplitude map of the current cycle, the images of some of the tomographic positions match those of the previous cycle, and the images of the remaining tomographic positions do not match those of the previous cycle, the magnetic resonance images of the current cycle are not used for registration, the three-dimensional amplitude map of the next cycle is registered with that of the previous cycle, and based on the registration relationship, the scanning parameters of the previous cycle are corrected to obtain new scanning parameters.

[0207] Specifically, referring to Figure 2 As shown in the figure, the upper part shows the state of the three-dimensional amplitude map of the previous cycle, and the middle part shows the state of the three-dimensional amplitude map generated in the current cycle. During the magnetic resonance image acquisition process of the current cycle, the patient moved. Since the patient movement occurred in a short period of time, and a group of magnetic resonance images needs a certain amount of time for acquisition, the three-dimensional amplitude map of the current cycle may appear as shown in the lower part of the figure.Figure 2 The A part of the figure corresponds to the state before the patient moves, and the B part corresponds to the state after the patient moves. The lower figure is a three-dimensional amplitude graph generated in the next cycle. In this case, the three-dimensional amplitude graph of the current cycle cannot be directly registered with the three-dimensional amplitude graph of the previous cycle (or the registration accuracy of direct registration is poor), and the three-dimensional amplitude graph of the current cycle itself can also be poor in quality (artifacts exist). At this time, the magnetic resonance image of the previous cycle is not used for registration (that is, the scanning parameter correction is not performed in the current cycle), and in the next cycle, the three-dimensional amplitude graph of the next cycle is registered with the three-dimensional amplitude graph of the previous cycle (the previous cycle and the next cycle are relative to the "current cycle" corresponding to the movement of the patient), and the current scanning parameter of the next cycle is corrected according to the registration relationship, which is used for subsequent magnetic resonance scanning.

[0208] In the case that the images of part of the tomographic positions in the three-dimensional amplitude graph of the current cycle match the previous cycle, and the images of the remaining tomographic positions do not match the previous cycle, the three-dimensional amplitude graph of the next cycle with more stable image quality is used to register with the three-dimensional amplitude graph of the previous cycle, a more accurate registration relationship is obtained, and the current scanning parameter is more reasonably corrected.

[0209] Based on any of the embodiments, in an embodiment, S13 comprises:

[0210] In the case that the images of part of the tomographic positions in the three-dimensional amplitude graph of the current cycle match the previous cycle, and the images of the remaining tomographic positions do not match the previous cycle, the scanning parameter of the previous cycle is corrected to obtain a new scanning parameter according to the registration relationship of the images of the remaining tomographic positions and the previous cycle.

[0211] Specifically, still referring to Figure 2 In the three-dimensional amplitude graph of the previous cycle, the A part directly corresponds to the part of the region in the same position of the previous cycle, which corresponds to the state before the patient moves, and the B part cannot directly correspond to the region in the same position of the previous cycle, which corresponds to the state after the patient moves. At this time, the current scanning parameter is corrected according to the registration relationship of the B part (that is, the image of the remaining tomographic position) and the three-dimensional amplitude graph of the previous cycle.

[0212] In the case that the images of part of the tomographic positions in the three-dimensional amplitude graph of the current cycle match the previous cycle, and the images of the remaining tomographic positions do not match the previous cycle, the three-dimensional amplitude graph of the next cycle with more stable image quality is used to register with the three-dimensional amplitude graph of the previous cycle, a more accurate registration relationship is obtained, and the current scanning parameter is more reasonably corrected.

[0213] A preferred embodiment of the present invention will now be described. Figure 3 This is a flowchart of a preferred embodiment of a magnetic resonance imaging (MRI) device scanning parameter correction method provided by the present invention, as shown below. Figure 3 As shown, the host receives and acquires positioning sequence scan images from the MRI machine, reconstructs a three-dimensional structural map of the patient's location based on the positioning sequence scan images, and determines the initial scan parameters. The host sends the initial scan parameters to the MRI machine for the first phase of rapid MRI scanning. Subsequently, if the scan parameters are corrected and updated, the host also sends the corrected and updated current scan parameters to the MRI machine, so that the MRI machine can perform rapid MRI scanning based on the corrected and updated current scan parameters. The host processes the data acquired by the MRI machine, obtaining a set of continuous MRI images per cycle. Based on each phase of MRI images, a three-dimensional temperature map and a three-dimensional amplitude map are constructed, and it is determined whether the current scan parameters need to be corrected. Specifically: first, the background area of ​​the current phase's three-dimensional amplitude map is compared with that of the previous phase's three-dimensional amplitude map. If the cumulative gray value change in the background area does not exceed the threshold, it is considered that the patient has not moved, and the current scan parameters can be used for the next phase of rapid MRI imaging. If the cumulative gray value change exceeds the threshold, it is necessary to further determine the inclusion of the target area in the current phase's three-dimensional amplitude map. If the target region is completely contained in the current three-dimensional amplitude map, it means that the current magnetic resonance imaging range can cover the target region, and the corresponding three-dimensional temperature... Figure Three Three-dimensional amplitude maps provide informational parameters for doctors without requiring correction of scan parameters. If the current cycle's three-dimensional amplitude map partially includes the target area, it indicates that the current MRI range cannot cover some target areas. In this case, the current cycle's three-dimensional amplitude map needs to be registered with the previous cycle's three-dimensional amplitude map. Based on the registration relationship, the current scan parameters are corrected (updated), and the corrected (updated) current scan parameters are used for the next cycle's rapid MRI. If the current cycle's three-dimensional amplitude map does not include the target area at all, it indicates that the patient has moved significantly, making it impossible to correct the current scan parameters based on the registration relationship between the current cycle's three-dimensional amplitude map and the previous cycle's three-dimensional amplitude map (registration is impossible, or the registration accuracy is low and does not meet the requirements). In this case, the current cycle's three-dimensional amplitude map needs to be registered with the localization three-dimensional structural map established based on the localization sequence scan. Based on this registration relationship and the initial scan parameters, new current scan parameters are determined for the next cycle's rapid MRI.

[0214] This invention provides a laser ablation device for magnetic resonance-guided laser interstitial hyperthermia, such as... Figure 4 As shown, the laser ablation device 400 includes:

[0215] The host 410 stores executable instructions, which, when executed, implement the magnetic resonance device parameter correction method described above, and correct the scanning parameters of the magnetic resonance device.

[0216] The laser ablation device 400 may also include a display device for displaying the processed three-dimensional temperature map and three-dimensional amplitude map, which is convenient for doctors to observe.

[0217] The present invention also provides a magnetic resonance-guided laser ablation system, which can be referred to in conjunction with the magnetic resonance device scanning parameter correction method and laser ablation device described above.

[0218] like Figure 5 As shown, the system includes: a magnetic resonance imaging device 510, and the aforementioned laser ablation device 400.

[0219] The magnetic resonance imaging device 510 is used to acquire magnetic resonance images according to the scanning parameters sent by the laser ablation device 400, and to send the acquired magnetic resonance images to the laser ablation device 400; the laser ablation device is used to process the magnetic resonance images and update the scanning parameters, and to send the updated scanning parameters to the magnetic resonance imaging device; the laser ablation device is also used to display the processed magnetic resonance images so that doctors can observe them and perform laser ablation operations.

[0220] Based on any embodiment, in one embodiment, the system further includes a laser ablation kit, which includes: a treatment light source module, a cooling circulation module, a cooling sleeve, and an ablation fiber.

[0221] Specifically, the treatment light source module is used to generate laser with the required power, the cooling circulation module is used to pump and recover coolant, the cooling sleeve is used to provide a circulation path for coolant and to cool the ablation fiber, and the ablation fiber is used to guide the laser into the target area for ablation.

[0222] Furthermore, the laser ablation kit may also include a temperature measurement module for measuring the temperature at the fiber optic ablation site, and the temperature measurement results can be cross-validated with the temperature results from magnetic resonance monitoring.

[0223] Furthermore, the laser ablation kit may also include a fiber adjustment module for adjusting the depth of the fiber. When the ablation fiber is a directional emission fiber, the fiber adjustment module can be configured to adjust both the fiber depth and the fiber angle.

[0224] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit the same; and although the present application has been described in detail with reference to the foregoing embodiments, it should be appreciated by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features thereof can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method of magnetic resonance device scan parameter correction for magnetic resonance guided laser interstitial thermotherapy, characterized in that, The method comprises: periodically performing fast magnetic resonance imaging on a target region, and obtaining a set of continuous magnetic resonance images in each period; for each set of continuous magnetic resonance images, establishing a three-dimensional temperature map according to a phase map in the magnetic resonance images, and establishing a three-dimensional amplitude map according to an amplitude map in the magnetic resonance images; for each period, generating new scanning parameters according to a registration relationship of the three-dimensional amplitude maps of the current period and a reference period, and using the new scanning parameters for fast magnetic resonance imaging in the next period; the reference period is a positioning sequence scan image obtained by pre-scanning a reference region, the reference region covers the target region, or the reference period is any corrected period.

2. The magnetic resonance device scan parameter correction method of claim 1, wherein, Before the periodically performing fast magnetic resonance imaging on a target region, and obtaining a set of continuous magnetic resonance images in each period, the method further comprises: obtaining a positioning sequence scan image, establishing a positioning three-dimensional structure map according to the positioning sequence scan image, and registering the positioning three-dimensional structure map with a preoperative three-dimensional image, so as to determine the position of the target region; wherein the preoperative three-dimensional image has a target region outlined or a target region automatically segmented; determining initial scanning parameters according to the position of the target region, or determining initial scanning parameters according to user input instructions.

3. The magnetic resonance device scan parameter correction method of claim 1, wherein, The periodically performing fast magnetic resonance imaging on a target region, and obtaining a set of continuous magnetic resonance images in each period comprises: determining a target region to be sampled in a current period according to a preset magnetic resonance down-sampling rule; performing magnetic resonance scanning on the target region to obtain a magnetic resonance image of the target region; obtaining continuous magnetic resonance images of the current period according to the magnetic resonance image of the target region.

4. The magnetic resonance device scan parameter correction method of claim 3, wherein, The preset magnetic resonance down-sampling rule is inter-layer down-sampling and / or intra-layer down-sampling.

5. The magnetic resonance device scan parameter correction method of claim 3, wherein, The obtaining continuous magnetic resonance images of the current period according to the magnetic resonance image of the target region comprises: obtaining continuous magnetic resonance images covering the target region by a reconstruction algorithm according to the magnetic resonance image of the target region; or obtaining the continuous magnetic resonance images covering the target region according to the magnetic resonance image of the target region and the magnetic resonance image of a complementary period thereof.

6. The magnetic resonance device scan parameter correction method of claim 2, wherein, The periodically performing fast magnetic resonance imaging on a target region, and obtaining a set of continuous magnetic resonance images in each period comprises: periodically performing scanning on the target region by a magnetic resonance fast imaging sequence; correcting the magnetic resonance images of the current period by using the reference period to obtain corrected magnetic resonance images.

7. The magnetic resonance device scan parameter correction method of claim 6, wherein, The reference period is any corrected period, and the correcting the magnetic resonance images of the current period by using the reference period comprises: obtaining distortion correction information according to a first position of a target structure in a magnetic resonance image of a reference period and a second position of the target structure in a magnetic resonance image of the reference period; wherein the reference period is a positioning sequence scan image obtained by pre-scanning a reference region, and the reference region covers the target region; correcting the magnetic resonance images of the current period according to the distortion correction information.

8. The magnetic resonance device scan parameter correction method of claim 1, wherein, After the for each set of continuous magnetic resonance images, establishing a three-dimensional temperature map according to a phase map in the magnetic resonance images, and establishing a three-dimensional amplitude map according to an amplitude map in the magnetic resonance images, the method further comprises: comparing the current cycle with the background region of the previous cycle; if the change of the accumulated gray value of the background region does not exceed the preset threshold, then entering the next cycle to perform the step of periodically performing fast magnetic resonance imaging on the target region; if the change of the accumulated gray value of the background region exceeds the preset threshold, then jumping to the step of generating new scanning parameters according to the registration relationship between the three-dimensional amplitude map of the current cycle and the reference cycle.

9. The magnetic resonance device scan parameter correction method of claim 8, wherein, The generating of the new scanning parameters according to the registration relationship between the three-dimensional amplitude map of the current cycle and the reference cycle comprises: registering the background region of the three-dimensional amplitude map of the current cycle with the background region of the three-dimensional amplitude map of the reference cycle, and correcting the scanning parameters of the reference cycle to obtain the new scanning parameters according to the registration relationship.

10. The magnetic resonance device scan parameter correction method of claim 1, wherein, After the three-dimensional temperature map is established according to the phase map in the magnetic resonance image and the three-dimensional amplitude map is established according to the amplitude map in the magnetic resonance image, the method further comprises: judging whether the three-dimensional amplitude map of the current cycle contains the target region or not; if the three-dimensional amplitude map of the current cycle completely contains the target region, then entering the next cycle to perform the step of periodically performing fast magnetic resonance imaging on the target region; if the three-dimensional amplitude map of the current cycle partially contains the target region, then jumping to the step of generating new scanning parameters according to the registration relationship between the three-dimensional amplitude map of the current cycle and the reference cycle; if the three-dimensional amplitude map of the current cycle does not contain the target region at all, then registering the three-dimensional amplitude map of the current cycle with the positioning three-dimensional structure map, and determining the new scanning parameters according to the registration relationship; wherein the positioning three-dimensional structure map is a three-dimensional amplitude map established according to a positioning sequence scanning image.

11. The magnetic resonance device scan parameter correction method of claim 1, wherein, The generating of the new scanning parameters according to the registration relationship between the three-dimensional amplitude map of the current cycle and the reference cycle comprises: in the three-dimensional amplitude map of the current cycle, the images of some tomographic positions match the previous cycle, and the images of the remaining tomographic positions do not match the previous cycle, correcting the scanning parameters of the previous cycle to obtain the new scanning parameters according to the registration relationship between the images of the remaining tomographic positions and the previous cycle; or, not using the magnetic resonance image of the current cycle for registration, but registering the three-dimensional amplitude map of the next cycle with the three-dimensional amplitude map of the previous cycle, and correcting the scanning parameters of the previous cycle to obtain the new scanning parameters according to the registration relationship.

12. An ablation device comprising a host computer, the host computer storing executable instructions which, when executed, implement the magnetic resonance device parameter correction method of any one of claims 1-11 to correct the scanning parameters of the magnetic resonance device.

13. A magnetic resonance guided laser ablation system, characterized in that, comprising: a magnetic resonance device, and the ablation device of claim 12.

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