Method, system, storage medium and device for in vivo measurement of mechanical properties of intervertebral disc

Abstract

The present invention relates to a method, system, storage medium and device for measuring the mechanical properties of an intervertebral disc in vivo, which comprises: collecting a first sequence and a second sequence of medical images of a target intervertebral disc; wherein the first sequence of medical images and the second sequence of medical images are medical image sequences under two different stress conditions respectively; after pre-processing the first sequence of medical images and the second sequence of medical images, performing registration and DVC operation to obtain intervertebral disc deformation data, and simultaneously measuring or estimating the geometric dimensions of the intervertebral disc before deformation and the load difference acting on the intervertebral disc under two stress conditions; based on the intervertebral disc deformation data, geometric dimensions and load difference, calculating the mechanical properties of the intervertebral disc. The present invention solves the problem that the existing method for measuring the mechanical properties of the intervertebral disc is invasive, and realizes the in vivo measurement of the mechanical properties of the intervertebral disc. The present invention can be widely used in the fields of biomechanics and medical imaging.

Description

Technical Field

[0001] The present invention relates to the field of biomechanics and medical imaging, and in particular to a method, system, storage medium and device for measuring the mechanical properties of intervertebral discs in vivo based on medical imaging of intervertebral discs under different stress conditions and DVC technology. Background Art

[0002] Low back pain is a very common and costly disease in today's society, and disc degeneration is the main cause of low back pain. Due to aging, long-term strain, trauma and other reasons, the nucleus pulposus of the intervertebral disc dehydrates, resulting in changes in the geometry and mechanical properties of the intervertebral disc, which loses its normal elasticity and tension and is insufficient to support the patient's large-scale activities. In severe cases, it can also compress nerves and cause pain symptoms. In vivo measurement of the mechanical properties of the intervertebral disc can improve the understanding of disc degeneration, thereby guiding the improvement of diagnostic and treatment methods, which is of great significance for the diagnosis and prevention of disc degeneration. There are many existing methods for measuring the mechanical properties of intervertebral discs, but all of them are invasive and can be divided into the following three categories: 1) Directly conduct mechanical loading experiments on ex vivo intervertebral disc specimens to obtain their stress-strain curves and mechanical properties such as the apparent effective elastic modulus of the intervertebral disc; 2) Use strain gauges to insert into ex vivo intervertebral disc specimens, conduct loading experiments on the ex vivo intervertebral disc specimens, obtain the strain inside the intervertebral disc, and calculate the mechanical properties of the intervertebral disc in combination with the loading mode; 3) Set radiological markers or embed physical markers on the end plates, periphery of the intervertebral disc, and mid-transverse plane of the ex vivo intervertebral disc sample, obtain its X-ray images before and after loading, reconstruct the three-dimensional position of each marker, obtain the strain of the intervertebral disc based on the relative displacement of the markers, and calculate the mechanical properties of the intervertebral disc in combination with the loading mode.

[0003] Existing methods for measuring the mechanical properties of intervertebral discs are all invasive and can only be used to measure the mechanical properties of intervertebral disc specimens in vitro. Since the mechanical properties of intervertebral discs are measured in vivo, it is impossible to directly perform mechanical loading experiments on the intervertebral discs; and inserting strain gauges or setting markers will cause the in vivo intervertebral disc structure to be destroyed, and this behavior that causes additional trauma to the human body is inhumane. The key to measuring the mechanical properties of intervertebral discs in vivo is to measure relatively accurate mechanical properties of intervertebral discs under the actual physiological structure of the intervertebral disc without using invasive means.

[0004] Therefore, the existing methods for measuring the mechanical properties of the intervertebral disc have strong limitations and cannot obtain the ideal in vivo mechanical properties of the intervertebral disc. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a method, system, storage medium and device for in vivo measurement of the mechanical properties of the intervertebral disc, which takes into account the real physiological and anatomical environment of the intervertebral disc, solves the problem that the existing methods for measuring the mechanical properties of the intervertebral disc are invasive, and realizes the in vivo measurement of the mechanical properties of the intervertebral disc.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a method for measuring the mechanical properties of an intervertebral disc in vivo, comprising: collecting a first sequence and a second sequence of medical images of a target intervertebral disc; wherein the first sequence and the second sequence of medical images are medical image sequences under two different stress conditions, respectively; after preprocessing the first sequence and the second sequence of medical images, registration and DVC operation are performed to obtain intervertebral disc deformation data, and at the same time, the geometric dimensions of the intervertebral disc and the load difference acting on the intervertebral disc under the two stress conditions are measured or estimated; based on the intervertebral disc deformation data, geometric dimensions and load difference under the two stress conditions, the mechanical properties of the target intervertebral disc are calculated.

[0007] Furthermore, the registration is: determining a registration reference area, registering the preprocessed first sequence and second sequence medical images based on the registration reference area, and obtaining the registered first sequence and the registered second sequence medical images.

[0008] Furthermore, the registration reference area is any vertebral body adjacent to the target intervertebral disc.

[0009] Furthermore, the DVC operation includes: repeatedly scanning and calculating virtual displacement of the preprocessed medical images to verify the image quality and obtain the optimal parameters of the DVC operation; performing DVC operation based on the first sequence of registered medical images and the second sequence of registered medical images, analyzing the grayscale features of the two sets of medical image sequences, and obtaining the deformation of the intervertebral disc.

[0010] Further, measuring or estimating the preprocessed first sequence and the preprocessed second sequence medical images includes:

[0011] Measure the geometric dimensions of the intervertebral disc based on the pre-processed medical image sequence;

[0012] Disc geometry includes the cross-sectional area of ​​the target disc and the thickness of the disc;

[0013] The load difference corresponding to the disc deformation was estimated based on the subjects' height, weight, spinal anatomy and morphology, and the weight information of the extracted weights.

[0014] Furthermore, the measurement and calculation of the intervertebral disc geometric dimensions are:

[0015] The intervertebral disc to be measured is approximated as a cylinder, and the central axis direction of the cylinder is defined as the measurement direction of the intervertebral disc thickness;

[0016] The thickness of the intervertebral disc was measured multiple times along the measuring direction and the average value was calculated. The average value was recorded as the intervertebral disc thickness.

[0017] The cross-sectional area of ​​the cylinder approximates the cross-sectional area of ​​the intervertebral disc.

[0018] Furthermore, the mechanical properties of the target intervertebral disc include elastic modulus and stiffness, and the elastic modulus is calculated as follows:

[0019]

[0020] Where, E is the elastic modulus of the intervertebral disc; ΔF is the load difference of the intervertebral disc under two different stress conditions, S is the cross-sectional area of ​​the intervertebral disc, H is the thickness of the intervertebral disc, and ΔH is the deformation of the intervertebral disc;

[0021] The stiffness is calculated as:

[0022] K=ΔF / ΔH

[0023] Among them, K is the stiffness of the intervertebral disc, ΔF is the load difference of the intervertebral disc under two different stress conditions, and ΔH is the deformation of the intervertebral disc.

[0024] A system for measuring the mechanical properties of an intervertebral disc in vivo comprises: an image acquisition module for acquiring a first sequence and a second sequence of medical images of a target intervertebral disc; wherein the first sequence and the second sequence of medical images are medical image sequences under two different stress conditions respectively; a processing module for preprocessing the first sequence and the second sequence of medical images, performing registration and DVC operation to obtain intervertebral disc deformation data, and simultaneously measuring or estimating the geometric dimensions of the intervertebral disc and the load difference acting on the intervertebral disc under the two stress conditions; and a calculation module for calculating the mechanical properties of the target intervertebral disc based on the intervertebral disc deformation data, geometric dimensions and load difference under the two stress conditions.

[0025] A computer-readable storage medium storing one or more programs, wherein the one or more programs include instructions, which, when executed by a computing device, cause the computing device to perform any of the above methods.

[0026] A computing device comprises: one or more processors, a memory and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include instructions for executing any of the above methods.

[0027] The present invention adopts the above technical solution, which has the following advantages:

[0028] 1. The present invention is based on medical image sequences under two stress conditions, uses DVC technology to obtain deformation data of the target intervertebral disc, and measures or estimates the geometric dimensions and load differences of the intervertebral disc. Based on the intervertebral disc deformation data, geometric dimensions and load differences, the mechanical properties of the intervertebral disc are calculated. In this way, the problem that the existing intervertebral disc measurement methods are invasive is solved as a starting point, and the problem that the existing means of measuring the mechanical properties of the intervertebral disc cannot be used for the human body is solved, providing a feasible method for measuring the mechanical properties of the intervertebral disc in vivo, which is of great significance.

[0029] 2. The present invention provides a feasible method for measuring the mechanical properties of the intervertebral disc in vivo and for quantifying the standard of intervertebral disc degeneration, or guides the improvement of treatment methods and evaluation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic flow chart of a method for in vivo measurement of mechanical properties of an intervertebral disc provided in an embodiment of the present invention;

[0031] Figure 2a A conventional supine spinal MRI image of a female volunteer provided in an embodiment of the present invention;

[0032] Figure 2b An example of a standing spinal MRI image of a female volunteer provided in an embodiment of the present invention;

[0033] Figure 3a A conventional supine MRI image of a female volunteer after pretreatment provided in an embodiment of the present invention;

[0034] Figure 3b An example of a standing MRI image of a female volunteer after preprocessing provided in an embodiment of the present invention;

[0035] Figure 4 An example of a conventional nuclear magnetic resonance image of a female volunteer after registration and an image superimposed with a conventional nuclear magnetic resonance image after registration provided in an embodiment of the present invention;

[0036] Figure 5 An illustrative diagram of relevant formulas provided for embodiments of the present invention. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0038] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0039] In order to solve the problem that the existing methods for measuring the mechanical properties of the intervertebral disc are highly invasive and cannot be applied to in vivo measurement. The embodiments of the present invention provide a method, system, storage medium and device for in vivo measurement of the mechanical properties of the intervertebral disc based on medical images and digital body correlation under two forces on the intervertebral disc. The mechanical properties of the intervertebral disc are obtained in vivo by combining the medical images under two forces on the intervertebral disc with the digital body correlation method. The medical images under the two forces on the intervertebral disc are preprocessed respectively, and the two groups of images are registered. The DVC method is used to analyze the grayscale features of the two groups of medical image sequences to obtain the displacement and strain of the intervertebral disc under force. The cross-sectional area and thickness of the intervertebral disc are measured by medical images, and the load difference before and after the deformation of the intervertebral disc is estimated. In this way, the problem that the existing intervertebral disc measurement method is invasive is solved as the starting point, and the problem that the existing means of measuring the mechanical properties of the intervertebral disc cannot be used for the human body is solved, and a feasible method is provided for in vivo measurement of the mechanical properties of the intervertebral disc, which is of great significance.

[0040] In one embodiment of the present invention, a method for measuring the mechanical properties of an intervertebral disc in vivo is provided. Figure 1 As shown, the method comprises the following steps:

[0041] 1) Acquiring a first sequence and a second sequence of medical images of the target intervertebral disc; wherein the first sequence and the second sequence of medical images are medical image sequences under two different stress conditions;

[0042] 2) After preprocessing the first sequence and the second sequence of medical images, registration and DVC operation are performed to obtain intervertebral disc deformation data, and the geometric size of the intervertebral disc and the difference in loads acting on the intervertebral disc under two force conditions are measured or estimated;

[0043] 3) Based on the intervertebral disc deformation data, geometric dimensions and load differences under two stress conditions, the mechanical properties of the target intervertebral disc are calculated.

[0044] In the above step 1), the first sequence and the second sequence of medical images are medical image sequences of two different stress conditions, respectively. In this embodiment, conventional supine and standing MRI images are used as the first sequence and the second sequence of medical images. The higher the resolution of the medical images used, the more accurate the mechanical properties of the intervertebral disc obtained.

[0045] Specifically, MRI scans were performed on the spines of volunteers in conventional supine and standing positions, and the scanning resolution was adjusted to obtain high-quality MRI image sequences that may contain intervertebral disc information, namely, the conventional supine and standing MRI image sequences mentioned above.

[0046] The volunteer's spine was scanned using Siemens MRI imaging equipment to obtain its T1 image sequence, which is the conventional supine MRI image sequence mentioned above; the volunteer's spine was scanned using Baisheng Medical's standing MRI imaging equipment to obtain the T1 image sequence, which is the standing MRI image sequence mentioned above. The images used in this embodiment are as follows Figure 2a , Figure 2b shown.

[0047] In the above step 2), the method for preprocessing the first sequence and the second sequence of medical images is not limited, and is determined according to the image quality of the two sets of medical images. The result of the preprocessing is to make the intervertebral discs in the conventional supine and standing medical image sequences clearly visible, and to complete the subsequent image registration and DVC operation steps.

[0048] Specifically, the preprocessing process of the images in the conventional supine position nuclear magnetic resonance imaging sequence and the standing position nuclear magnetic resonance imaging sequence includes:

[0049] 2.1.1) Unify the voxel size of conventional supine MRI images and standing MRI images;

[0050] 2.1.2) Unify the grayscale value range of conventional supine and standing MRI images;

[0051] 2.1.3) Crop the image size of conventional supine MRI images and standing MRI images. The result is as follows Figure 3a , Figure 3b shown.

[0052] In the above step 2), the registration is: determining a registration reference area, registering the preprocessed first sequence and the preprocessed second sequence medical images based on the registration reference area, and obtaining the registered first sequence and the registered second sequence medical images.

[0053] The registration reference area is any vertebral body adjacent to the intervertebral disc being measured.

[0054] In this embodiment, the pre-processed conventional supine and standing MRI image sequences are manually registered during the registration process. The lower vertebral body of the intervertebral disc under test is selected as the registration reference area in the pre-processed conventional supine and standing MRI image sequences. The registration standard method used is the correlation between the two sets of images in the pre-processed conventional supine and standing positions. The image registration process is performed with the pre-processed conventional supine MRI image sequence as the reference image. The registration results are shown in Figure 2. Figure 4 shown.

[0055] In the above step 2), the DVC operation is as follows: before the DVC operation, the pre-processed medical image is repeatedly scanned and virtually displaced to verify the image quality and analyze the optimal parameters of the DVC operation, the DVC operation is performed based on the first sequence of medical images after registration and the second sequence of medical images after registration, the grayscale features of the two sets of medical image sequences are analyzed, the displacement and strain of the intervertebral disc when subjected to force are obtained, and the image is repeatedly scanned and virtually displaced to verify the image quality and obtain the optimal parameters of the DVC operation.

[0056] In this embodiment, the DVC operation is a digital volume correlation method (DVC), which uses the grayscale difference formed in the image as the deformation information carrier, optimizes the objective function by combining the numerical optimization algorithm and the grayscale interpolation algorithm, determines the change in the coordinate position of the volume image of the object under test before and after the deformation, and calculates the three-dimensional displacement vector field of the region. The parameters used in the DVC operation are adjusted according to the resolution when the image is acquired.

[0057] Furthermore, before DVC calculation, the image needs to be repeatedly scanned and virtually displaced to verify the image quality and the optimal parameters of the DVC operation, analyze errors, and compromise between the spatial resolution and accuracy of the DVC measurement, including: repeated scanning and analysis of the imaging of two groups of samples to be tested, which is used to evaluate the errors caused by micro-motion of the imaging system and image noise; the virtual displacement method is used to analyze the same imaging of the sample in the same state and its rigid movement (i.e., moving one voxel along the x, y, and z axes respectively) imaging, which is used to evaluate the sensitivity of the DVC algorithm to the contrast and texture characteristics of the sample under the parameters, so as to determine the optimal DVC subvolume size.

[0058] After repeated scanning of the image to verify the image quality and the optimal parameters of the virtual displacement analysis DVC operation, the DVC operation analysis was performed based on the conventional supine and standing MRI images after registration with a sub-volume size of 50 mm and a grid size of 25 mm. The DVC operation results were exported to obtain the deformation data of the second intervertebral disc.

[0059] In the above step 2), measuring or estimating the preprocessed first sequence and the preprocessed second sequence medical images includes:

[0060] 2.2.1) Calculate the geometric dimensions of the intervertebral disc based on the preprocessed medical image sequence;

[0061] The geometric dimensions including the cross-sectional area and thickness of the target intervertebral disc are measured and calculated based on the preprocessed medical image sequence.

[0062] In this embodiment, the geometric dimensions of the intervertebral disc are calculated by manual measurement based on a pre-processed conventional supine MRI image sequence.

[0063] The measurement and calculation of the geometric dimensions of the intervertebral disc are as follows: the intervertebral disc to be measured is approximated as a cylinder, and the central axis direction of the cylinder is defined as the measurement direction of the intervertebral disc thickness; the thickness of the intervertebral disc is measured multiple times along the measurement direction and the average is calculated, and the average is recorded as the thickness of the intervertebral disc; the cross-sectional area of ​​the cylinder is approximately the cross-sectional area of ​​the intervertebral disc.

[0064] Furthermore, the thickness of the intervertebral disc is measured multiple times along the measuring direction and the average is calculated, wherein the multiple measurements refer to finding five equal points of the intervertebral disc width in the central coronal plane and the central sagittal plane of the intervertebral disc, specifying these eight points as measuring points, measuring the thickness of the intervertebral disc along the measuring direction at the measuring points and calculating the average, which is recorded as the intervertebral disc thickness.

[0065] Specifically, the original thickness of the intervertebral disc is manually measured based on the conventional supine MRI image sequence after preprocessing. If the intervertebral disc is still not clear enough after preprocessing, adjust the image exposure and brightness until the intervertebral disc in the conventional supine MRI image sequence after preprocessing can be clearly identified. Approximate the measured intervertebral disc as a cylinder, and define the central axis direction of the cylinder as the measurement direction of the intervertebral disc. Measure the thickness of the intervertebral disc multiple times along the measurement direction and calculate the average, which is recorded as the thickness of the intervertebral disc. Find the five equal points of the width of the intervertebral disc in the central coronal plane of the conventional supine MRI image after preprocessing and the central sagittal plane of the conventional supine MRI image after preprocessing, respectively, measure the thickness of the intervertebral disc at these eight measurement points along the measurement direction and calculate the average, which is recorded as the thickness of the intervertebral disc. Approximate the intervertebral disc as a cylinder, and the cross-sectional area of ​​the cylinder is the cross-sectional area of ​​the intervertebral disc.

[0066] 2.2.2) Estimate the load difference corresponding to the intervertebral disc deformation based on the subject's height, weight, spinal anatomy and morphology, and the weight information of the extracted weight;

[0067] In this embodiment, according to the Chinese anthropometry standard and the position of the center of gravity, combined with the height, weight, spinal anatomical structure and morphology of the subject and the weight information of the extracted heavy object, the parameters such as the proportion of each segment of the human body, the position of the center of gravity, and the weight ratio are determined. According to the principle of statics, the force model of the intervertebral disc when lying flat and standing is established, and the equilibrium equation is listed to estimate the difference in the load when the intervertebral disc is deformed.

[0068] In the above step 3), the mechanical properties of the target intervertebral disc include elastic modulus and mechanical property stiffness of the intervertebral disc. The calculation of the elastic model is:

[0069] like Figure 5 As shown in the figure, the intervertebral disc is deformed by force. The intervertebral disc is approximated as a cylinder. The calculation formula of the elastic modulus of the mechanical properties of the intervertebral disc in the elastic deformation stage is:

[0070]

[0071] Where, E is the elastic modulus of the intervertebral disc; ΔF is the load difference of the intervertebral disc under two different stress conditions, S is the cross-sectional area of ​​the intervertebral disc, H is the thickness of the intervertebral disc, and ΔH is the deformation of the intervertebral disc;

[0072] The mechanical property stiffness calculation formula is:

[0073] K=ΔF / ΔH

[0074] Among them, K is the stiffness of the intervertebral disc, ΔF is the load difference of the intervertebral disc under two different stress conditions, and ΔH is the deformation of the intervertebral disc. Based on the intervertebral disc deformation data, geometric dimensions and load differences under the two stress conditions, the mechanical properties of the target intervertebral disc can be calculated.

[0075] The embodiment of the present invention is based on conventional supine and standing MRI images, and uses DVC to analyze the grayscale features of conventional supine and standing medical image sequences to obtain the deformation size of the target intervertebral disc. The thickness, cross-sectional area and stress condition of the target intervertebral disc are measured or estimated by preprocessing the conventional supine medical image sequence. However, the method of the present invention is not limited to conventional supine and standing positions, and can also analyze any other group of images under different stress conditions to achieve in vivo measurement of the mechanical properties of the intervertebral disc.

[0076] Based on the intervertebral disc deformation data, geometric dimensions and load differences, the mechanical properties of the intervertebral disc are calculated. This is to solve the problem that the existing intervertebral disc measurement methods are invasive, solve the problem that the existing means of measuring the mechanical properties of the intervertebral disc cannot be used for the human body, and provide a feasible method for measuring the mechanical properties of the intervertebral disc in vivo, which is of great significance.

[0077] In one embodiment of the present invention, a system for measuring mechanical properties of an intervertebral disc in vivo based on medical images and digital body correlation measurements of the intervertebral disc under two forces is provided, comprising:

[0078] An image acquisition module, which acquires a first sequence and a second sequence of medical images of the target intervertebral disc; wherein the first sequence and the second sequence of medical images are medical image sequences under two different stress conditions respectively;

[0079] A processing module, which pre-processes the first sequence and the second sequence of medical images, performs registration and DVC operation to obtain intervertebral disc deformation data, and simultaneously measures or estimates the geometric size of the intervertebral disc and the difference in loads acting on the intervertebral disc under two force conditions;

[0080] The calculation module calculates the mechanical properties of the target intervertebral disc based on the intervertebral disc deformation data, geometric dimensions and load differences under two force conditions.

[0081] Among them, the preprocessing operation in the processing module is used to unify the first sequence and the second sequence of medical images to facilitate subsequent image registration and DVC operations, which include but are not limited to: unifying voxel size, unifying grayscale value range, and cropping image sequences; registration is to align the preprocessed first sequence and the preprocessed second sequence of medical images based on the vertebrae adjacent to the intervertebral disc to obtain the registered conventional supine and standing medical image sequences; DVC operation is used to set appropriate parameters according to the registered first sequence and the pre-registered second sequence of medical images to perform DVC operation to obtain the deformation of the intervertebral disc; measurement is used to measure or estimate the preprocessed first sequence and / or the preprocessed second sequence of medical images to obtain the intervertebral disc geometric size of the target intervertebral disc and the load difference under two stress conditions.

[0082] The system provided in this embodiment is used to execute the above-mentioned method embodiments. Please refer to the above-mentioned embodiments for specific processes and detailed contents, which will not be repeated here.

[0083] In one embodiment of the present invention, a computing device structure is provided, and the computing device may be a terminal, which may include: a processor, a communications interface, a memory, a display screen, and an input device. Among them, the processor, the communications interface, and the memory communicate with each other through a communication bus. The processor is used to provide computing and control capabilities. The memory includes a non-volatile storage medium and an internal memory, and the non-volatile storage medium stores an operating system and a computer program. When the computer program is executed by the processor, a method for measuring the mechanical properties of an intervertebral disc in vivo is implemented; the internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a management network, NFC (near field communication) or other technologies. The display screen may be a liquid crystal display screen or an electronic ink display screen, and the input device may be a touch layer covered on the display screen, or a key, trackball or touchpad provided on the housing of the computing device, or an external keyboard, touchpad or mouse. The processor can call the logic instructions in the memory to execute the following method: collecting a first sequence and a second sequence of medical images of the target intervertebral disc; wherein the first sequence and the second sequence of medical images are medical image sequences under two different stress conditions respectively; after pre-processing the first sequence and the second sequence of medical images, registration and DVC operation are performed to obtain intervertebral disc deformation data, and at the same time, the geometric dimensions of the intervertebral disc and the load difference under two stress conditions are measured or estimated; based on the intervertebral disc deformation data, geometric dimension data and load difference, the mechanical properties of the target intervertebral disc are calculated.

[0084] In addition, the logic instructions in the above-mentioned memory can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0085] Those skilled in the art will understand that the structure of the above-mentioned computing device is only a partial structure related to the scheme of the present application, and does not constitute a limitation on the computing device to which the scheme of the present application is applied. The specific computing device may include more or fewer components, or combine certain components, or have a different arrangement of components.

[0086] In one embodiment of the present invention, a computer program product is provided, the computer program product comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions, and when the program instructions are executed by a computer, the computer can execute the methods provided by the above-mentioned method embodiments, for example, comprising: acquiring a first sequence and a second sequence of medical images of a target intervertebral disc; wherein the first sequence and the second sequence of medical images are medical image sequences under two different stress conditions, respectively; after pre-processing the first sequence and the second sequence of medical images, performing alignment and DVC operation to obtain intervertebral disc deformation data, and simultaneously measuring or estimating the geometric dimensions of the intervertebral disc and the load difference under the two stress conditions; based on the intervertebral disc deformation data, geometric dimension data and load difference, calculating the mechanical properties of the target intervertebral disc.

[0087] In one embodiment of the present invention, a non-transitory computer-readable storage medium is provided, which stores server instructions, and the computer instructions enable a computer to execute the methods provided by the above embodiments, for example, including: acquiring a first sequence and a second sequence of medical images of a target intervertebral disc; wherein the first sequence and the second sequence of medical images are medical image sequences under two different stress conditions, respectively; after pre-processing the first sequence and the second sequence of medical images, aligning and performing DVC operations to obtain intervertebral disc deformation data, and simultaneously measuring or estimating the geometric dimensions of the intervertebral disc and the load difference under the two stress conditions; based on the intervertebral disc deformation data, geometric dimension data and load difference, calculating the mechanical properties of the target intervertebral disc.

[0088] The above embodiment provides a computer-readable storage medium, whose implementation principle and technical effect are similar to those of the above method embodiment, and will not be repeated here.

[0089] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0090] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0091] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for measuring the mechanical properties of an intervertebral disc in vivo, characterized in that: include: Acquire a first sequence and a second sequence of medical images of the target intervertebral disc; wherein the first sequence and the second sequence of medical images are medical image sequences under two different stress conditions; After preprocessing the first sequence and the second sequence of medical images, registration and DVC operation are performed to obtain the intervertebral disc deformation data, and the geometric size of the intervertebral disc and the difference in loads acting on the intervertebral disc under two force conditions are measured or estimated; Based on the disc deformation data, geometric dimensions and load differences under two stress conditions, the mechanical properties of the target disc are calculated; The registration includes: determining a registration reference area, registering the preprocessed first sequence and second sequence medical images based on the registration reference area, and obtaining the registered first sequence and the registered second sequence medical images.

2. The method for measuring the mechanical properties of intervertebral discs in vivo as claimed in claim 1, characterized in that: The registration reference area is any vertebral body adjacent to the target intervertebral disc.

3. The method for measuring the mechanical properties of intervertebral discs in vivo according to claim 1, characterized in that: The DVC operation includes: performing repeated scanning and virtual displacement calculation on the preprocessed medical images to verify the image quality and obtain the optimal parameters of the DVC operation; performing DVC operation based on the first sequence of registered medical images and the second sequence of registered medical images, analyzing the grayscale features of the two sets of medical image sequences, and obtaining the deformation of the intervertebral disc.

4. The method for measuring the mechanical properties of intervertebral discs in vivo according to claim 1, characterized in that: Measuring or estimating the preprocessed first sequence and the preprocessed second sequence medical images, including: Measure the geometric dimensions of the intervertebral disc based on the pre-processed medical image sequence; Disc geometry includes the cross-sectional area of ​​the target disc and the thickness of the disc; The load difference corresponding to the disc deformation was estimated based on the subjects' height, weight, spinal anatomy and morphology, and the weight information of the extracted weights.

5. The method for measuring the mechanical properties of intervertebral discs in vivo as claimed in claim 4, characterized in that: The measurement of the intervertebral disc geometry is calculated as: The intervertebral disc to be measured is approximated as a cylinder, and the central axis direction of the cylinder is defined as the measurement direction of the intervertebral disc thickness; The thickness of the intervertebral disc was measured multiple times along the measuring direction and the average value was calculated. The average value was recorded as the intervertebral disc thickness. The cross-sectional area of ​​the cylinder approximates the cross-sectional area of ​​the intervertebral disc.

6. The method for measuring the mechanical properties of intervertebral discs in vivo according to claim 1, characterized in that: The mechanical properties of the target intervertebral disc include elastic modulus and stiffness. The elastic modulus is calculated as follows: Where, E is the elastic modulus of the intervertebral disc; ΔF is the load difference of the intervertebral disc under two different stress conditions, S is the cross-sectional area of ​​the intervertebral disc, H is the thickness of the intervertebral disc, and ΔH is the deformation of the intervertebral disc; The stiffness is calculated as: K=ΔF / ΔH Among them, K is the stiffness of the intervertebral disc, ΔF is the load difference of the intervertebral disc under two different stress conditions, and ΔH is the deformation of the intervertebral disc.

7. A system for measuring the mechanical properties of intervertebral discs in vivo, characterized in that: include: An image acquisition module, which acquires a first sequence and a second sequence of medical images of the target intervertebral disc; wherein the first sequence and the second sequence of medical images are medical image sequences under two different stress conditions respectively; A processing module, which pre-processes the first sequence and the second sequence of medical images, performs registration and DVC operation to obtain intervertebral disc deformation data, and simultaneously measures or estimates the geometric size of the intervertebral disc and the difference in loads acting on the intervertebral disc under two force conditions; The calculation module calculates the mechanical properties of the target intervertebral disc based on the intervertebral disc deformation data, geometric dimensions and load differences under two stress conditions; The registration includes: determining a registration reference area, registering the preprocessed first sequence and second sequence medical images based on the registration reference area, and obtaining the registered first sequence and the registered second sequence medical images.

8. A computer-readable storage medium storing one or more programs, characterized in that: The one or more programs include instructions, and when the instructions are executed by a computing device, the computing device performs any one of the methods of claims 1 to 6.

9. A computing device, characterized in that include: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include instructions for executing any one of the methods described in claims 1 to 6.

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