Method and system for spatial localization and morphological analysis of three-dimensional nuclear magnetic resonance footprint regions

Abstract

The application provides a three-dimensional nuclear magnetic resonance footprint area spatial positioning and morphological analysis method and system, comprising the following steps: S1, obtaining a weighted 3D MRI magnetic resonance image, and performing footprint area layer reconstruction; S2, obtaining an image parallel to the footprint area plane, and determining a spatial positioning area; S3, performing footprint area outlining, and segmenting the footprint area; and S4, performing spatial positioning analysis and morphological analysis on the footprint area. By adopting the 3D MRI reconstruction technology, the application can accurately evaluate the ACL femoral footprint area in the oblique sagittal plane which is tangent to the attachment point of the ACL and the femur, solves the inaccurate problem of the ACL femoral footprint area morphological evaluation in the traditional 2D MRI evaluation method, and thus provides more accurate ACL femoral footprint area morphological information for doctors, and further optimizes the effect of the ACL reconstruction surgery.

Description

Technical Field

[0001] This invention relates to the field of image processing, specifically to a method and system for spatial localization and morphological analysis of footprint areas based on three-dimensional magnetic resonance imaging; more specifically, it relates to a method and system for spatial localization and morphological analysis of the anterior cruciate ligament femoral footprint area based on three-dimensional magnetic resonance imaging. Background Technology

[0002] In the field of ACL femoral footprint morphology assessment, ScheffLer et al. have used 3D MRI to assess the morphology of the ACL femoral footprint region, and their research results have been published in paper PMID 29728742. However, ScheffLer et al.'s method has limitations in the selection of parameters for 3D MRI scanning and the determination of the reconstructed section. These limitations may result in their assessed femoral footprint regions having similar morphologies, deviating from the ACL femoral footprint region morphology found in previous anatomical studies, thus affecting the outcome of ACL reconstruction surgery. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method and system for spatial localization and morphological analysis of footprint regions based on three-dimensional nuclear magnetic resonance imaging.

[0004] A method for spatial localization and morphological analysis of footprint regions based on three-dimensional nuclear magnetic resonance imaging, provided by the present invention, includes:

[0005] Step S1: Acquire weighted 3D MRI images and perform footprint area reconstruction;

[0006] Step S2: Obtain an image parallel to the plane of the footprint area to determine the spatial positioning area;

[0007] Step S3: Outline the footprint area and divide the footprint area;

[0008] Step S4: Perform spatial positioning and morphological analysis on the footprint area.

[0009] Preferably, in step S1:

[0010] Step S1.1: Using a 3.0T MR system with a knee coil, T1-weighted 3D MRI images of the subject were acquired using a T1-weighted 3D sequence;

[0011] Step S1.2: Footprint area reconstruction:

[0012] Based on the anatomical location of the anterior cruciate ligament on the medial wall of the lateral femoral condyle, the anterior cruciate ligament footprint area was located in the coronal and axial planes, respectively. The footprint area was then reconstructed in oblique sagittal 3D to generate image I.

[0013] Preferably, in step S2:

[0014] Step S2.1: Positioning line, acquire an image parallel to the plane of the footprint area, mark the Blumensa line on the parallel plane, position the parallel line L of the Blumensa line on the plane of the footprint area, rotate the image so that the parallel line L of the Blumensa line is horizontal and located above the footprint area, and denote the image as I;

[0015] Step S2.2: Selection of the three positioning points ACP:

[0016] Draw two tangents perpendicular to line L. One tangent, m, is located at the distal boundary of the lateral femoral condyle, and the intersection of this tangent with line L is the first positioning point A. The other tangent, n, is located at the apex of the posterior condyle of the lateral femoral condyle, and the intersection of this tangent with line L is the second positioning point C. Then draw a line t parallel to L, tangent to the posterior aspect of the lateral femoral condyle, and the point of tangency between the t-line and the posterior aspect of the lateral femoral condyle is the third positioning point P.

[0017] Step S2.3: Determine the positioning area: Use three positioning points as the boundaries of the positioning area, and determine a rectangular frame as the positioning area R0; this area contains all the pixels of the footprint area. Cut the image within R0 and save it as image I2. Establish a coordinate system with the top left vertex as the origin and the horizontal and vertical directions as x and y respectively. The four vertices and their coordinates are denoted as: A(0,0), B(0,y1), C(x1,0), D(x1,y1);

[0018] Step S2.4: Divide the positioning area into sub-regions: Divide the positioning area into M rows * N columns to form M * N positioning partitions.

[0019] Preferably, in step S3:

[0020] Footprint area segmentation: Using image analysis software, the footprint area is delineated and the region of interest F of the complete footprint area is segmented, with the center point and coordinates FF(x,y).

[0021] Preferably, in step S4:

[0022] Step S4.1: Spatial positioning analysis: Record the positioning sub-region where the center point FF of the footprint area is located, and calculate the relative position (x0, y0) of the center point FF of the footprint area in the positioning area R0. The calculation method is: x0 = x / x1; y0 = y / y1;

[0023] Step S4.2: Morphological analysis: Select and analyze the morphological indicators of the footprint area F, including area, shape classification, roundness, longest diameter and shortest diameter.

[0024] A spatial localization and morphological analysis system for footprint regions based on three-dimensional nuclear magnetic resonance imaging, provided by the present invention, includes:

[0025] Module M1: Acquire weighted 3D MRI images and perform footprint area reconstruction;

[0026] Module M2: Acquires an image parallel to the plane of the footprint area to determine the spatial positioning area;

[0027] Module M3: Outline and segment the footprint area;

[0028] Module M4: Performs spatial positioning and morphological analysis on the footprint area.

[0029] Preferably, in module M1:

[0030] Module M1.1: Using a 3.0T MR system with a knee coil, T1-weighted 3D sequences are used to acquire T1-weighted 3D MRI images of the subject;

[0031] Module M1.2: Footprint Area Level Reconstruction:

[0032] Based on the anatomical location of the anterior cruciate ligament on the medial wall of the lateral femoral condyle, the anterior cruciate ligament footprint area was located in the coronal and axial planes, respectively. The footprint area was then reconstructed in oblique sagittal 3D to generate image I.

[0033] Preferably, in module M2:

[0034] Module M2.1: Positioning line, acquire an image parallel to the footprint area plane, mark the Blumensa line on the parallel plane, position the parallel line L of the Blumensa line on the footprint area plane, rotate the image so that the parallel line L of the Blumensa line is horizontal and above the footprint area, and denote the image as I;

[0035] Module M2.2: Selection of three positioning points (ACP):

[0036] Draw two tangents perpendicular to line L. One tangent, m, is located at the distal boundary of the lateral femoral condyle, and the intersection of this tangent with line L is the first positioning point A. The other tangent, n, is located at the apex of the posterior condyle of the lateral femoral condyle, and the intersection of this tangent with line L is the second positioning point C. Then draw a line t parallel to L, tangent to the posterior aspect of the lateral femoral condyle, and the point of tangency between the t-line and the posterior aspect of the lateral femoral condyle is the third positioning point P.

[0037] Module M2.3: Determine the positioning area: Use three positioning points as the boundary of the positioning area, and determine a rectangular box as the positioning area R0; this area contains all the pixels of the footprint area. Cut the image within R0 and save it as image I2. Establish a coordinate system with the top left vertex as the origin and the horizontal and vertical directions as x and y respectively. The four vertices and their coordinates are denoted as: A(0,0), B(0,y1), C(x1,0), D(x1,y1);

[0038] Module M2.4: Divide the positioning area into sub-regions: Divide the positioning area into M rows * N columns to form M * N positioning partitions.

[0039] Preferably, in module M3:

[0040] Footprint area segmentation: Using image analysis software, the footprint area is delineated and the region of interest F of the complete footprint area is segmented, with the center point and coordinates FF(x,y).

[0041] Preferably, in module M4:

[0042] Module M4.1: Spatial Positioning Analysis: Record the positioning sub-region where the center point FF of the footprint area is located, and calculate the relative position (x0, y0) of the center point FF of the footprint area in the positioning region R0. The calculation method is: x0 = x / x1; y0 = y / y1;

[0043] Module M4.2: Morphological Analysis: Select and analyze the morphological parameters of the footprint area F, including area, shape classification, roundness, longest diameter and shortest diameter.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] 1. This invention uses 3D MRI reconstruction technology to accurately assess the ACL femoral footprint area in the oblique sagittal plane, which is closely tangent to the attachment point of the ACL and the femur. This solves the problem of inaccurate assessment of the ACL femoral footprint area morphology in the traditional 2D MRI assessment method, thereby providing doctors with more accurate ACL femoral footprint area morphology information and optimizing the effect of ACL reconstruction surgery.

[0046] 2. This invention uses high spatial resolution 3D-SPACE sequences to evaluate the ACL femoral footprint area, ensuring high image quality and accuracy, thereby further improving the accuracy of the evaluation;

[0047] 3. This invention addresses the drawbacks of significant individual differences in the footprint area, which hinders technical exchange and dissemination, by standardizing the spatial positioning and segmentation of the footprint area relative to the medial wall of the lateral femoral condyle of the anterior cruciate ligament. This facilitates the design of standardized surgical techniques, academic exchanges, and patient follow-up. Attached Figure Description

[0048] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0049] Figure 1 This is a patent flowchart;

[0050] Figure 2The image shown is the reconstructed and rotated image in the example.

[0051] Figure 3 The image shown is a segmented image for the localization area in the embodiment. Detailed Implementation

[0052] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0053] Example 1:

[0054] This invention proposes a method and device for spatial localization and morphological analysis of the femoral footprint area of ​​the anterior cruciate ligament (ACL) of the knee joint based on three-dimensional magnetic resonance imaging (3D MRI), which can be used to guide ACL surgical localization, graft selection and design, and postoperative efficacy evaluation.

[0055] The present invention provides a method for spatial localization and morphological analysis of footprint regions based on three-dimensional nuclear magnetic resonance imaging, such as... Figures 1-3 As shown, it includes:

[0056] Step S1: Acquire weighted 3D MRI images and perform footprint area reconstruction;

[0057] Specifically, in step S1:

[0058] Step S1.1: Using a 3.0T MR system with a knee coil, T1-weighted 3D MRI images of the subject were acquired using a T1-weighted 3D sequence;

[0059] Step S1.2: Footprint area reconstruction:

[0060] Based on the anatomical location of the anterior cruciate ligament on the medial wall of the lateral femoral condyle, the anterior cruciate ligament footprint area was located in the coronal and axial planes, respectively. The footprint area was then reconstructed in oblique sagittal 3D to generate image I.

[0061] Step S2: Obtain an image parallel to the plane of the footprint area to determine the spatial positioning area;

[0062] Specifically, in step S2:

[0063] Step S2.1: Positioning line, acquire an image parallel to the plane of the footprint area, mark the Blumensa line on the parallel plane, position the parallel line L of the Blumensa line on the plane of the footprint area, rotate the image so that the parallel line L of the Blumensa line is horizontal and located above the footprint area, and denote the image as I;

[0064] Step S2.2: Selection of the three positioning points ACP:

[0065] Draw two tangents perpendicular to line L. One tangent, m, is located at the distal boundary of the lateral femoral condyle, and the intersection of this tangent with line L is the first positioning point A. The other tangent, n, is located at the apex of the posterior condyle of the lateral femoral condyle, and the intersection of this tangent with line L is the second positioning point C. Then draw a line t parallel to L, tangent to the posterior aspect of the lateral femoral condyle, and the point of tangency between the t-line and the posterior aspect of the lateral femoral condyle is the third positioning point P.

[0066] Step S2.3: Determine the positioning area: Use three positioning points as the boundaries of the positioning area, and determine a rectangular frame as the positioning area R0; this area contains all the pixels of the footprint area. Cut the image within R0 and save it as image I2. Establish a coordinate system with the top left vertex as the origin and the horizontal and vertical directions as x and y respectively. The four vertices and their coordinates are denoted as: A(0,0), B(0,y1), C(x1,0), D(x1,y1);

[0067] Step S2.4: Divide the positioning area into sub-regions: Divide the positioning area into M rows * N columns to form M * N positioning partitions.

[0068] Step S3: Outline the footprint area and divide the footprint area;

[0069] Specifically, in step S3:

[0070] Footprint area segmentation: Using image analysis software, the footprint area is delineated and the region of interest F of the complete footprint area is segmented, with the center point and coordinates FF(x,y).

[0071] Step S4: Perform spatial positioning and morphological analysis on the footprint area.

[0072] Specifically, in step S4:

[0073] Step S4.1: Spatial positioning analysis: Record the positioning sub-region where the center point FF of the footprint area is located, and calculate the relative position (x0, y0) of the center point FF of the footprint area in the positioning area R0. The calculation method is: x0 = x / x1; y0 = y / y1;

[0074] Step S4.2: Morphological analysis: Select and analyze the morphological indicators of the footprint area F, including area, shape classification, roundness, longest diameter and shortest diameter.

[0075] Example 2:

[0076] Example 2 is a preferred embodiment of Example 1, and is used to illustrate the present invention in more detail.

[0077] The present invention also provides a spatial localization and morphological analysis system for footprint regions based on three-dimensional nuclear magnetic resonance imaging (NMR). The spatial localization and morphological analysis system for footprint regions based on three-dimensional NMR can be implemented by executing the process steps of the method for spatial localization and morphological analysis of footprint regions based on three-dimensional NMR. That is, those skilled in the art can understand the method for spatial localization and morphological analysis of footprint regions based on three-dimensional NMR as a preferred embodiment of the spatial localization and morphological analysis system for footprint regions based on three-dimensional NMR.

[0078] A spatial localization and morphological analysis system for footprint regions based on three-dimensional nuclear magnetic resonance imaging, provided by the present invention, includes:

[0079] Module M1: Acquire weighted 3D MRI images and perform footprint area reconstruction;

[0080] Specifically, in module M1:

[0081] Module M1.1: Using a 3.0T MR system with a knee coil, T1-weighted 3D sequences are used to acquire T1-weighted 3D MRI images of the subject;

[0082] Module M1.2: Footprint Area Level Reconstruction:

[0083] Based on the anatomical location of the anterior cruciate ligament on the medial wall of the lateral femoral condyle, the anterior cruciate ligament footprint area was located in the coronal and axial planes, respectively. The footprint area was then reconstructed in oblique sagittal 3D to generate image I.

[0084] Module M2: Acquires an image parallel to the plane of the footprint area to determine the spatial positioning area;

[0085] Specifically, in module M2:

[0086] Module M2.1: Positioning line, acquire an image parallel to the footprint area plane, mark the Blumensa line on the parallel plane, position the parallel line L of the Blumensa line on the footprint area plane, rotate the image so that the parallel line L of the Blumensa line is horizontal and above the footprint area, and denote the image as I;

[0087] Module M2.2: Selection of three positioning points (ACP):

[0088] Draw two tangents perpendicular to line L. One tangent, m, is located at the distal boundary of the lateral femoral condyle, and the intersection of this tangent with line L is the first positioning point A. The other tangent, n, is located at the apex of the posterior condyle of the lateral femoral condyle, and the intersection of this tangent with line L is the second positioning point C. Then draw a line t parallel to L, tangent to the posterior aspect of the lateral femoral condyle, and the point of tangency between the t-line and the posterior aspect of the lateral femoral condyle is the third positioning point P.

[0089] Module M2.3: Determine the positioning area: Use three positioning points as the boundary of the positioning area, and determine a rectangular box as the positioning area R0; this area contains all the pixels of the footprint area. Cut the image within R0 and save it as image I2. Establish a coordinate system with the top left vertex as the origin and the horizontal and vertical directions as x and y respectively. The four vertices and their coordinates are denoted as: A(0,0), B(0,y1), C(x1,0), D(x1,y1);

[0090] Module M2.4: Divide the positioning area into sub-regions: Divide the positioning area into M rows * N columns to form M * N positioning partitions.

[0091] Module M3: Outline and segment the footprint area;

[0092] Specifically, in module M3:

[0093] Footprint area segmentation: Using image analysis software, the footprint area is delineated and the region of interest F of the complete footprint area is segmented, with the center point and coordinates FF(x,y).

[0094] Module M4: Performs spatial positioning and morphological analysis on the footprint area.

[0095] Specifically, in module M4:

[0096] Module M4.1: Spatial Positioning Analysis: Record the positioning sub-region where the center point FF of the footprint area is located, and calculate the relative position (x0, y0) of the center point FF of the footprint area in the positioning region R0. The calculation method is: x0 = x / x1; y0 = y / y1;

[0097] Module M4.2: Morphological Analysis: Select and analyze the morphological parameters of the footprint area F, including area, shape classification, roundness, longest diameter and shortest diameter.

[0098] Example 3:

[0099] Example 3 is a preferred example of Example 1, and is used to illustrate the present invention in more detail.

[0100] Step 1: Using a 3.0T MR system with a knee coil, T1-weighted 3D MRI images of the subject are acquired using a T1-weighted 3D sequence (e.g., 3D SPACE sequence).

[0101] Step 2: Footprint area reconstruction

[0102] Based on the anatomical location of the anterior cruciate ligament on the medial wall of the lateral femoral condyle, the anterior cruciate ligament footprint area was located in the coronal and axial planes, respectively. The footprint area was then reconstructed in oblique sagittal 3D to generate image I.

[0103] Step 3: Determining the Spatial Positioning Area

[0104] 3.1 Positioning Line: Obtain an image parallel to the plane of the footprint area, mark the Blumensa line on the parallel plane, and then position the parallel line L of the Blumensa line on the plane of the footprint area. Rotate image I so that L is horizontal and above the footprint area, and still denote the image as I for subsequent analysis.

[0105] 3.2 Selection of the three positioning points (ACP):

[0106] Draw two tangents perpendicular to line L. One tangent, m, lies at the distal boundary of the lateral femoral condyle, and its intersection with line L is the first location point A. The other tangent, n, lies at the apex of the posterior condyle of the lateral femoral condyle, and its intersection with line L is the second location point C. Then draw a line t parallel to L, tangent to the posterior aspect of the lateral femoral condyle. The point of tangency between the t-line and the posterior aspect of the lateral femoral condyle is the third location point P.

[0107] 3.3 Determine the positioning area: Using three positioning points as the boundaries of the positioning area, define a rectangular frame as the positioning area R0; this area must contain all pixels of the footprint area. Cut the image within R0 and save it as image I2. Establish a coordinate system with the top-left vertex as the origin and the x and y directions as the horizontal and vertical directions, respectively. The four vertices and their coordinates are denoted as: A(0,0), B(0,y1), C(x1,0), D(x1,y1).

[0108] 3.4 Divide the positioning area into sub-regions: Divide the positioning area into M rows * N columns (4*4 in the example), forming M*N positioning partitions R1, ..., RMN (R1., ..., R16 in the example).

[0109] Step 4: Footprint area segmentation: Using image analysis software, the footprint area is delineated, and the region of interest F of the complete footprint area is segmented, with the center point and coordinates FF(x,y).

[0110] Step 5: Spatial positioning analysis: Record the positioning sub-region where the center point FF of the footprint area is located (in the example: the 9th sub-region R9), and calculate the relative position (x0, y0) of the center point FF of the footprint area in the positioning region R0 (in the example: (0.57, 0.64)). The calculation method is: x0 = x / x1; y0 = y / y1.

[0111] Step 6: Morphological analysis: Select and analyze the morphological indicators of the footprint area F, including but not limited to area, shape classification, roundness, longest diameter, shortest diameter, etc. (In the example: area = 60 mm2, shape classification = circle).

[0112] Those skilled in the art will understand that, besides implementing the system and its various devices, modules, and units provided by this invention in the form of purely computer-readable program code, the same functions can be achieved entirely through logical programming of the method steps, making the system and its various devices, modules, and units of this invention function in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers. Therefore, the system and its various devices, modules, and units provided by this invention can be considered as a hardware component, and the devices, modules, and units included therein for implementing various functions can also be considered as structures within the hardware component; alternatively, the devices, modules, and units for implementing various functions can be considered as both software modules implementing the method and structures within the hardware component.

[0113] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for spatial localization and morphological analysis of footprint regions based on three-dimensional nuclear magnetic resonance imaging, characterized in that, include: Step S1: Acquire weighted 3D MRI images and perform footprint area reconstruction; Step S2: Obtain an image parallel to the plane of the footprint area to determine the spatial positioning area; Step S3: Outline the footprint area and divide the footprint area; Step S4: Perform spatial positioning and morphological analysis on the footprint area; In step S2: Step S2.1: Positioning line, acquire an image parallel to the plane of the footprint area, mark the Blumensa line on the parallel plane, position the parallel line L of the Blumensa line on the plane of the footprint area, rotate the image so that the parallel line L of the Blumensa line is horizontal and located above the footprint area, and denote the image as I; Step S2.2: Selection of the three positioning points ACP: Draw two tangents perpendicular to line L. One tangent, m, is located at the distal boundary of the lateral femoral condyle, and the intersection of this tangent with line L is the first positioning point A. The other tangent, n, is located at the apex of the posterior condyle of the lateral femoral condyle, and the intersection of this tangent with line L is the second positioning point C. Then draw a line t parallel to L, tangent to the posterior aspect of the lateral femoral condyle, and the point of tangency between the t-line and the posterior aspect of the lateral femoral condyle is the third positioning point P. Step S2.3: Determine the positioning area: Use three positioning points as the boundaries of the positioning area, and determine a rectangular frame as the positioning area R0; this positioning area contains all the pixels of the footprint area. Cut the image within R0 and save it as image I2. Establish a coordinate system with the top left vertex as the origin and the horizontal and vertical directions as x and y respectively. The four vertices and their coordinates are denoted as: A(0,0), B(0,y1), C(x1,0), D(x1,y1). Step S2.4: Divide the positioning area into sub-regions: Divide the positioning area into M rows * N columns to form M * N positioning partitions.

2. The method for spatial localization and morphological analysis of footprint regions based on three-dimensional nuclear magnetic resonance as described in claim 1, characterized in that, In step S1: Step S1.1: Using a 3.0 T MR system with a knee coil, T1-weighted 3D MRI images of the subject were acquired using a T1-weighted 3D sequence; Step S1.2: Footprint area reconstruction: Based on the anatomical location of the anterior cruciate ligament on the medial wall of the lateral femoral condyle, the anterior cruciate ligament footprint area was located in the coronal and axial planes, respectively. The footprint area was then reconstructed in oblique sagittal 3D to generate image I.

3. The method for spatial localization and morphological analysis of footprint regions based on three-dimensional nuclear magnetic resonance as described in claim 1, characterized in that, In step S3: Footprint area segmentation: Using image analysis software, the footprint area is delineated and the region of interest F of the complete footprint area is segmented, with the center point and coordinates FF(x,y).

4. The method for spatial localization and morphological analysis of footprint regions based on three-dimensional nuclear magnetic resonance as described in claim 1, characterized in that, In step S4: Step S4.1: Spatial positioning analysis: Record the positioning sub-region where the center point FF of the footprint area is located, and calculate the relative position (x0, y0) of the center point FF of the footprint area in the positioning area R0. The calculation method is: x0=x / x1; y0=y / y1; Step S4.2: Morphological analysis: Select and analyze the morphological indicators of the footprint area F, including area, shape classification, roundness, longest diameter and shortest diameter.

5. A system for spatial localization and morphological analysis of footprint regions based on three-dimensional nuclear magnetic resonance imaging, characterized in that, include: Module M1: Acquire weighted 3D MRI images and perform footprint area reconstruction; Module M2: Acquires an image parallel to the plane of the footprint area to determine the spatial positioning area; Module M3: Outline and segment the footprint area; Module M4: Performs spatial positioning and morphological analysis on the footprint area; In module M2: Module M2.1: Positioning line, acquire an image parallel to the footprint area plane, mark the Blumensa line on the parallel plane, position the parallel line L of the Blumensa line on the footprint area plane, rotate the image so that the parallel line L of the Blumensa line is horizontal and above the footprint area, and denote the image as I; Module M2.2: Selection of three positioning points (ACP): Draw two tangents perpendicular to line L. One tangent, m, is located at the distal boundary of the lateral femoral condyle, and the intersection of this tangent with line L is the first positioning point A. The other tangent, n, is located at the apex of the posterior condyle of the lateral femoral condyle, and the intersection of this tangent with line L is the second positioning point C. Then draw a line t parallel to L, tangent to the posterior aspect of the lateral femoral condyle, and the point of tangency between the t-line and the posterior aspect of the lateral femoral condyle is the third positioning point P. Module M2.3: Determine the positioning area: Use three positioning points as the boundaries of the positioning area, and define a rectangular frame as the positioning area R0; this positioning area contains all pixels of the footprint area. Cut the image within R0 and save it as image I2. Establish a coordinate system with the top left vertex as the origin and the horizontal and vertical directions as x and y respectively. The four vertices and their coordinates are denoted as: A(0,0), B(0,y1), C(x1,0), D(x1,y1). Module M2.4: Divide the positioning area into sub-regions: Divide the positioning area into M rows * N columns to form M * N positioning partitions.

6. The spatial localization and morphological analysis system for footprint regions based on three-dimensional nuclear magnetic resonance imaging according to claim 5, characterized in that, In module M1: Module M1.1: Using a 3.0 T MR system with a knee coil, T1-weighted 3D sequences are used to acquire T1-weighted 3D MRI images of the subject; Module M1.2: Footprint Area Level Reconstruction: Based on the anatomical location of the anterior cruciate ligament on the medial wall of the lateral femoral condyle, the anterior cruciate ligament footprint area was located in the coronal and axial planes, respectively. The footprint area was then reconstructed in oblique sagittal 3D to generate image I.

7. The spatial localization and morphological analysis system for footprint regions based on three-dimensional nuclear magnetic resonance imaging according to claim 5, characterized in that, In module M3: Footprint area segmentation: Using image analysis software, the footprint area is delineated and the region of interest F of the complete footprint area is segmented, with the center point and coordinates FF(x,y).

8. The spatial localization and morphological analysis system for footprint regions based on three-dimensional nuclear magnetic resonance imaging according to claim 5, characterized in that, In module M4: Module M4.1: Spatial Positioning Analysis: Record the positioning sub-region where the center point FF of the footprint area is located, and calculate the relative position (x0, y0) of the center point FF of the footprint area in the positioning region R0. The calculation method is: x0=x / x1; y0=y / y1; Module M4.2: Morphological Analysis: Select and analyze the morphological parameters of the footprint area F, including area, shape classification, roundness, longest diameter and shortest diameter.

Images