Femoral greater trochanter parameter measurement method and device based on CT three-dimensional reconstruction images

Abstract

The present invention discloses a method and device for measuring the parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images, belonging to the field of computer technology. The invention determines the anatomical landmark points required for measuring the parameters of the greater trochanter of the femur, proposes a measurement scheme for mapping and analyzing a large sample of medical images, solves the problems of poor data representativeness and reduces the measurement system error, etc., realizes efficient, convenient and accurate parameter measurement, can realize the rapid and accurate quantification of the parameters of the greater trochanter of the human femur, and further provides morphological support for total hip arthroplasty. At the same time, the invention participates in the morphological clustering analysis of the greater trochanter of the femur, is used to propose morphological subtypes of the greater trochanter of the femur, provides ideas for instrument design, and lays a solid foundation for clinical translational application.

Description

Technical Field

[0001] The present invention relates to the field of computer technology, and in particular to a method and device for measuring the parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images. Background Art

[0002] The greater trochanter of the femur is a square eminence on the upper outer side of the junction of the femoral neck and the body, and is an important anatomical landmark of the femur. For example, it is used to measure the length of the lower limb, and to judge femoral neck fractures and hip dislocations. The greater trochanter has multiple muscle attachment points, including the gluteus medius, gluteus minimus, obturator internus, obturator externus, superior gemellus, inferior gemellus, and piriformis muscles, and is an important load-bearing structure of the hip joint. In the population with normal hip joint development, the three-dimensional position of the greater trochanter matches the length and morphology of the muscles, and plays a key role in the range of motion and stability of the hip joint.

[0003] In China, patients with developmental dysplasia of the hip are the second leading cause of total hip arthroplasty. Such patients often have abnormal three-dimensional positions of the greater trochanter of the femur. During the operation, three-dimensional reconstruction of the muscles and bones is required to ensure the normal recovery of the patient's hip joint movement ability after the operation. In the prior art, during the operation of total hip arthroplasty, the surgeon mainly evaluates the patient's condition based on two-dimensional X-ray films, prepares multiple types of prostheses during the operation, determines the final femoral prosthesis type and placement position through multiple intraoperative trials, and confirms the prosthesis placement site again through one or even multiple intraoperative X-ray films. At the same time, due to the size of the intraoperative incision and the occlusion of muscle tissue, the complete morphology of the femur cannot be revealed. The surgeon mainly judges whether the femoral prosthesis is placed in place by empirical feeling.

[0004] In the prior art, the measurement techniques for the morphological characteristics of the greater trochanter of the femur are mainly two-dimensional measurements based on X-ray films, and the structure of the greater trochanter is judged based on artificial experience to achieve the purpose of quantitative analysis. The height of femoral dislocation is determined by measuring the distance between the greater trochanter of the hip joint and the highest point of the pelvis on the X-ray film to judge whether muscle reconstruction is needed. However, the X-ray film projects the three-dimensional structure into a two-dimensional flat film. Due to the non-standard body position of the lower limbs of the person being photographed, the shooting result will be deviated; due to its inherent defects, there are differences in the projection angles of the X-ray tube, and muscle imaging cannot be achieved. The surgeon lacks the judgment of the morphology of the hip joint muscles, and the muscles attached to the greater trochanter are the most vulnerable parts during the operation; the abnormal femoral height caused by developmental dysplasia of the hip poses higher requirements for prosthesis installation. The surgeon needs to make a detailed plan for the hip joint muscle mechanics to determine the intraoperative implementation plan, but there is no detailed and repeatable method. These reasons lead to great limitations in X-ray film measurement. Summary of the Invention

[0005] To solve the problems in the above-mentioned existing technologies, the present invention provides a method and device for measuring the parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images. The invention can quickly and accurately quantify the parameters of the greater trochanter of the human femur, thereby providing morphological support for total hip arthroplasty; at the same time, the invention participates in the morphological clustering analysis of the greater trochanter of the femur in order to propose morphological subtypes of the greater trochanter of the femur, providing ideas for instrument design. To achieve the above object, the technical solutions are as follows:

[0006] On the one hand, a method for measuring the parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images is provided. The method includes:

[0007] S1. Obtain CT data, model the CT data, and obtain a three-dimensional model according to the extracted pelvic, femur of the side to be studied, and muscle data;

[0008] S2. Determine reference points according to the three-dimensional model;

[0009] S3. Perform three-dimensional processing on the three-dimensional model according to the reference points to obtain three-dimensional processing data;

[0010] S4. Obtain the contour calibration regions of the muscles at each CT slice according to the three-dimensional processing data;

[0011] S5. Obtain the three-dimensional reconstruction and in-situ fitting models of the contour calibration regions of the muscles at each slice according to the contour calibration regions of the muscles at each slice;

[0012] S6. Obtain the highest point J of the greater trochanter, the lowest point K of the ipsilateral acetabular notch, the highest point L of the ipsilateral pelvis, and the highest point M of the acetabular rim according to the three-dimensional reconstruction and in-situ fitting models of the contour calibration regions of the muscles at each slice. According to the points J, K, L, and M, measure the vertical distances from the horizontal plane passing through point J to points K, L, and M to obtain points N, O, and P, which are the positions to be measured;

[0013] S7. Reconstruct the CT data by using the threshold segmentation and region growing methods according to the in-situ fitting model and the positions to be measured to obtain measurement parameters;

[0014] S8. Measure the positions to be measured according to the measurement parameters to obtain measurement data.

[0015] Optionally, the determining reference points according to the three-dimensional model in S2 includes:

[0016] Randomly select 8 points on the medial side of the acetabulum, marked as points A1 - A8, perform spherical fitting on the points A1 - A8, requiring that the sum of the vertical distances from the fitted circular surface to the 8 points is the smallest, and obtain the center of the sphere marked as point B. According to the three - dimensional model, obtain the most prominent positioning point C1 of the left anterior superior iliac spine and the most prominent positioning point C2 of the right anterior superior iliac spine.

[0017] Optionally, the linear distance between any two of the points A1 - A8 is not less than 1 cm.

[0018] Optionally, obtaining the three - dimensional model according to the extracted pelvis, the femur on the side to be studied, and muscle data includes:

[0019] Rotate the femur with point B as the rotation center so that the line connecting the tip of the greater trochanter of the femur and the mid - point of the intercondylar fossa of the femur, that is, the anatomical axis of the femur, is perpendicular to the horizontal plane.

[0020] Optionally, the three - dimensional processing models the fibrocartilage connecting the two pubic bones at the pubic symphysis to obtain model C. According to model C, bisect the upper and lower parts of model C for planar positioning to obtain section C. According to section C, extend the axis to bisect the straight line of section C for positioning to obtain straight line C. According to the most anterior point of straight line C, that is, the mid - point of the pubic symphysis, obtain the mid - point C3 of the pubic symphysis. Rotate the pelvis with point B as the rotation center so that the plane formed by points C1, C2, and C3 is perpendicular to the horizontal plane, and re - cut the CT data according to the rotated angle.

[0021] Optionally, the contour calibration area includes the area where the gluteus medius muscle connects to the greater trochanter of the femur marked as area D, the area where the gluteus minimus muscle connects to the greater trochanter of the femur marked as area E, the area where the obturator internus muscle connects to the greater trochanter of the femur marked as area F, the area where the obturator externus muscle connects to the greater trochanter of the femur marked as area G, the area where the superior gemellus muscle connects to the greater trochanter of the femur marked as area H, the area where the inferior gemellus muscle connects to the greater trochanter of the femur marked as area I, and the area where the piriformis muscle connects to the greater trochanter of the femur marked as area Q.

[0022] Optionally, S4 obtains the contour calibration area of the muscles on each CT slice according to the three - dimensional processing data, including:

[0023] S41: Denote the point on the muscle contour closest to the sagittal plane passing through the mid - line of the human body on each plane as the first closest point, and denote the point on the muscle contour farthest from the sagittal plane passing through the mid - line of the human body on each plane as the first farthest point. Mark and connect the first closest point and the first farthest point into a straight line, and divide the muscle contour into two curves through the straight line connected by the first closest point and the first farthest point;

[0024] S42: Calculate the vertical distances from the points on the two curves to the straight line;

[0025] S43. If there exists a specific point such that the vertical distance is the maximum or the minimum, then determine the specific point as the marked point, and connect any two of the marked point, the first nearest point, and the first farthest point to form a closed curve.

[0026] Optionally, the in-situ fitting model includes the in-situ fitting model D at the connection between the gluteus medius and the greater trochanter of the femur, the in-situ fitting model E at the connection between the gluteus minimus and the greater trochanter of the femur, the in-situ fitting model F at the connection between the obturator internus and the greater trochanter of the femur, the in-situ fitting model G at the connection between the obturator externus and the greater trochanter of the femur, the in-situ fitting model H at the connection between the superior gemellus and the greater trochanter of the femur, the in-situ fitting model I at the connection between the inferior gemellus and the greater trochanter of the femur, and the in-situ fitting model Q at the connection between the piriformis and the greater trochanter of the femur.

[0027] Optionally, the step in S43 of connecting any two of the marked point, the first nearest point, and the first farthest point to form a closed curve includes:

[0028] Connect any two of the marked point, the first nearest point, and the first farthest point to form a closed curve, fill the closed curve with a color, and set the transparency to 30%.

[0029] On the other hand, a device for measuring the parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images is provided. This device is applied to a method for measuring the parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images. The device includes:

[0030] An extraction module, configured to obtain CT data and perform modeling on the CT data. The extraction module obtains a three-dimensional model according to the extracted pelvic bone, the femur of the side to be studied, and muscle data.

[0031] A reference point determination module, configured to determine a reference point according to the three-dimensional model.

[0032] A three-dimensional processing module, configured to perform three-dimensional processing on the three-dimensional model according to the reference point to obtain three-dimensional processing data.

[0033] A contour calibration module, configured to obtain the contour calibration regions of the muscles in each CT slice according to the three-dimensional processing data.

[0034] A model fitting module, configured to obtain the three-dimensional reconstruction and in-situ fitting models of the contour calibration regions of the muscles according to the contour calibration regions of the muscles in each slice.

[0035] A position determination module, configured to obtain the highest point J of the greater trochanter, the lowest point K of the ipsilateral acetabular notch, the highest point L of the ipsilateral pelvis, and the highest point M of the acetabular rim according to the three-dimensional reconstruction and in-situ fitting model of the contour calibration regions of the respective layers of muscles, and measure the vertical distances from the horizontal plane passing through point J to points K, L, and M respectively according to points J, K, L, and M to obtain points N, O, and P, that is, the positions to be measured;

[0036] A model reconstruction module, configured to reconstruct the CT data by using a threshold segmentation and region growing method according to the in-situ fitting model and the positions to be measured to obtain measurement parameters;

[0037] A measurement module, configured to measure the positions to be measured according to the measurement parameters to obtain measurement data.

[0038] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:

[0039] The above solution solves the problems of poor representativeness of the prior art data and reduces the measurement system error, etc., realizes efficient, convenient and accurate parameter measurement, can realize the rapid and accurate quantification of the parameters of the greater trochanter of the human femur, and further provides morphological support for total hip arthroplasty. At the same time, the invention participates in the morphological clustering analysis of the greater trochanter of the femur to propose morphological subclasses of the greater trochanter of the femur, provides ideas for instrument design, and lays a solid foundation for clinical translational application. Description of the Drawings

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0041] Figure 1 It is a flowchart of a method for measuring the parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images provided by an embodiment of the present invention;

[0042] Figure 2 It is a schematic diagram of the positions of reference points A1 - A8 provided by an embodiment of the present invention;

[0043] Figure 3 It is a schematic diagram of the position of point B provided by an embodiment of the present invention;

[0044] Figure 4 It is a schematic diagram of a model C provided by an embodiment of the present invention;

[0045] Figure 5Schematic diagram of the position of the contour calibration area provided by an embodiment of the present invention;

[0046] Figure 6 Marking diagram of area D provided by an embodiment of the present invention;

[0047] Figure 7 Marking diagram of area E provided by an embodiment of the present invention;

[0048] Figure 8 Marking diagram of area F provided by an embodiment of the present invention;

[0049] Figure 9 Marking diagram of area G provided by an embodiment of the present invention;

[0050] Figure 10 Marking diagram of area H provided by an embodiment of the present invention;

[0051] Figure 11 Marking diagram of area I provided by an embodiment of the present invention;

[0052] Figure 12 Marking diagram of area Q provided by an embodiment of the present invention;

[0053] Figure 13 Schematic diagram of the position to be measured provided by an embodiment of the present invention;

[0054] Figure 14 Block diagram of a device for measuring the parameters of the greater trochanter of the femur based on a CT three-dimensional reconstruction image provided by an embodiment of the present invention. Detailed implementation manners

[0055] The following describes the technical solutions in the present invention with reference to the accompanying drawings.

[0056] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as an "example" in the present invention should not be construed as being more preferred or more advantageous than other embodiments or design solutions. Exactly speaking, the use of the word "example" aims to present concepts in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or either of the two can be selected.

[0057] To make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments.

[0058] As Figures 1 to 14As shown, a method for measuring the parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images provided by an embodiment of the present invention can be implemented by a device for measuring the parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images, such as Figure 1 As shown, a flowchart of a method for measuring the parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images provided by an embodiment of the present invention, the method includes the following steps:

[0059] S1. Obtain CT data, model the CT data, and obtain a three-dimensional model according to the extracted pelvic bone, the femur to be studied, and muscle data.

[0060] S2. Determine reference points according to the three-dimensional model;

[0061] Specifically, as Figure 2 shown, the reference points are 8 points randomly selected inside the acetabulum, marked as points A1 - A8. Perform spherical fitting on the points A1 - A8, and require that the sum of the vertical distances from the fitted circular surface to the 8 points is the smallest. As Figure 3 shown, obtain the center of the sphere marked as point B. According to the three-dimensional model, obtain the most prominent positioning point C1 of the left anterior superior iliac spine and the most prominent positioning point C2 of the right anterior superior iliac spine.

[0062] Specifically, the linear distance between any two of the points A1 - A8 is not less than 1 cm.

[0063] Specifically, the obtaining of the three-dimensional model according to the extracted pelvic bone, the femur to be studied, and muscle data includes:

[0064] Rotate the femur with point B as the rotation center so that the connection line between the tip of the greater trochanter of the femur and the midpoint of the intercondylar fossa of the femur, that is, the anatomical axis of the femur, is perpendicular to the horizontal plane.

[0065] S3. Perform three-dimensional processing on the three-dimensional model according to the reference points;

[0066] Specifically, as Figure 4 shown, the three-dimensional processing is modeled according to the fibrocartilage connecting the two pubic bones at the pubic symphysis to obtain model C. According to model C, bisect the upper and lower parts of model C for plane positioning to obtain section C. According to section C, extend the axis to bisect the straight line of section C for positioning to obtain straight line C. According to the most forward point of straight line C, that is, the midpoint of the pubic symphysis, obtain the midpoint C3 of the pubic symphysis. Rotate the pelvis with point B as the rotation center so that the plane formed by points C1, C2, and C3 is perpendicular to the horizontal plane, and re-cut the CT data according to the rotated angle.

[0067] S4. Obtain the contour calibration area of the muscles at each CT level according to the three-dimensional processing data;

[0068] Specifically, asFigure 5 As shown, the contour calibration area includes the area marked as area D at the connection between the gluteus medius muscle and the greater trochanter of the femur, the area marked as area E at the connection between the gluteus minimus muscle and the greater trochanter of the femur, the area marked as area F at the connection between the obturator internus muscle and the greater trochanter of the femur, the area marked as area G at the connection between the obturator externus muscle and the greater trochanter of the femur, the area marked as area H at the connection between the superior gemellus muscle and the greater trochanter of the femur, the area marked as area I at the connection between the inferior gemellus muscle and the greater trochanter of the femur, and the area marked as area Q at the connection between the piriformis muscle and the greater trochanter of the femur.

[0069] Specifically, step S4 of obtaining the contour calibration area of each layer of muscle in the CT based on the three-dimensional processing data includes:

[0070] S41: Denote the point on the muscle contour of each plane that is closest to the sagittal plane passing through the midline of the human body as the first closest point, and denote the point on the muscle contour of each plane that is farthest from the sagittal plane passing through the midline of the human body as the first farthest point. Mark and connect the first closest point and the first farthest point into a straight line, and divide the muscle contour into two curved lines by the straight line connected by the first closest point and the first farthest point;

[0071] S42: Calculate the perpendicular distance from the points on the two curved lines to the straight line;

[0072] S43: If there exists a specific point such that the perpendicular distance is the maximum or minimum, then determine the specific point as the marked point, and connect any two of the marked point, the first closest point, and the first farthest point to form a closed curve.

[0073] Specifically, fill the closed curve with a color and set the transparency to 30%.

[0074] S5: Obtain the three-dimensional reconstruction and in-situ fitting model of the contour calibration area of each layer of muscle based on the contour calibration area of each layer of muscle;

[0075] Specifically, the in-situ fitting model includes the in-situ fitting model D at the connection between the gluteus medius muscle and the greater trochanter of the femur, the in-situ fitting model E at the connection between the gluteus minimus muscle and the greater trochanter of the femur, the in-situ fitting model F at the connection between the obturator internus muscle and the greater trochanter of the femur, the in-situ fitting model G at the connection between the obturator externus muscle and the greater trochanter of the femur, the in-situ fitting model H at the connection between the superior gemellus muscle and the greater trochanter of the femur, the in-situ fitting model I at the connection between the inferior gemellus muscle and the greater trochanter of the femur, and the in-situ fitting model Q at the connection between the piriformis muscle and the greater trochanter of the femur.

[0076] Specifically, as Figure 6 shown, mark the connections between the gluteus medius muscle and the greater trochanter of the femur on each layer from the head side to the foot side as D1, D2, D3, D4 until D n , and mark D1, D2, D3, D4 until D nPerform three-dimensional reconstruction and move it onto the three-dimensional femoral model to overlap them in situ, marked as region D. From the cranial to the caudal direction, mark the point on the gluteus medius muscle contour closest to the sagittal plane passing through the midline of the human body on each plane as point D 1-1 to point D 1-n , and from the cranial to the caudal direction, mark the point on the gluteus medius muscle contour farthest from the sagittal plane passing through the midline of the human body on each plane as point D 2-1 to point D 2-n , point D 1-n and point D 2-n Divide the muscle contour into two curves, connect D 1-n and point D 2-n , mark it as line D, calculate the perpendicular distance from the points on these two curves to line D. If there is a point where the perpendicular distances from the points on both sides to the line decrease or increase simultaneously, mark this point. Finally, connect the marked points, point D 1-n , and point D 2-n connect adjacent points pairwise to form a closed curve. From the cranial to the caudal direction, set the transparency of the color filled in the closed curve on each plane to 30% and mark it as regions D1 to D n , and fit regions D1 to D n in situ with the femoral model after three-dimensional reconstruction, marked as model D.

[0077] As Figure 7 shown, mark the connections between the gluteus minimus and the greater trochanter of the femur on each level from the cranial to the caudal direction as E1, E2, E3, E4 until En, and for E1, E2, E3, E4 until E n Perform three-dimensional reconstruction and move it onto the three-dimensional femoral model to overlap them in situ, marked as region E. From the cranial to the caudal direction, mark the point on the gluteus medius muscle contour closest to the sagittal plane passing through the midline of the human body on each plane as point E 1-1 to point E 1-n , and from the cranial to the caudal direction, mark the point on the gluteus medius muscle contour farthest from the sagittal plane passing through the midline of the human body on each plane as point E 2-1 to point E 2-n , point E 1-n and point E 2-n Divide the muscle contour into two curves, connect E 1-n and point E 2-n , mark it as line E, calculate the perpendicular distance from the points on these two curves to line E. If there is a point where the perpendicular distances from the points on both sides to the line decrease or increase simultaneously, mark this point. Finally, connect the marked points, point E 1-n , and point E 2-n connect adjacent points pairwise to form a closed curve. From the cranial to the caudal direction, set the transparency of the color filled in the closed curve on each plane to 30% and mark it as regions E1 to E n , and for regions E1 to En After three-dimensional reconstruction, it is fitted in situ with the femoral model and marked as model E.

[0078] As Figure 8 shown, the connections between the obturator internus muscle and the greater trochanter of the femur at each level are marked as F1, F2, F3, F4 from the cranial side to the caudal side until F n , and F1, F2, F3, F4 until F n are three-dimensionally reconstructed and moved onto the three-dimensional femoral model to overlap them in situ, marked as region F. The points on the muscle contour of the gluteus medius muscle closest to the sagittal plane passing through the midline of the human body on each plane are marked as point F 1-1 to point F 1-n , and the points on the muscle contour of the gluteus medius muscle farthest from the sagittal plane passing through the midline of the human body on each plane are marked as point F 2-1 to point F 2-n , point F 1-n and point F 2-n divide the muscle contour into two curves. Connect F 1-n and point F 2-n , marked as line F. Calculate the perpendicular distances from the points on these two curves to line F. If there is a point where the perpendicular distances from the points on both sides to the line decrease or increase uniformly, then mark this point. Finally, connect the marked points, point F 1-n , point F 2-n and adjacent two points pairwise to form a closed curve. On each plane from the cranial side to the caudal side, set the transparency of the color filled inside the closed curve to 30% and mark it as region F1 to F n , and after three-dimensional reconstruction of region F1 to F n , fit it in situ with the femoral model and mark it as model F.

[0079] As Figure 9 shown, the connections between the obturator externus muscle and the greater trochanter of the femur at each level are marked as G1, G2, G3, G4 from the cranial side to the caudal side until G n , and G1, G2, G3, G4 until G n are three-dimensionally reconstructed and moved onto the three-dimensional femoral model to overlap them in situ, marked as region G. The points on the muscle contour of the gluteus medius muscle closest to the sagittal plane passing through the midline of the human body on each plane are marked as point G 1-1 to point G 1-n , and the points on the muscle contour of the gluteus medius muscle farthest from the sagittal plane passing through the midline of the human body on each plane are marked as point G 2-1 to point G 2-n , point G 1-n and point G 2-n divide the muscle contour into two curves. Connect G 1-n and point G 2-nConnect the lines, marked as straight line G, and calculate the perpendicular distances from the points on these two curves to the straight line G. If there is a point where the perpendicular distances from the points on both sides to the straight line decrease or increase simultaneously, then mark this point. Finally, mark the marked points and point G 1-n and point G 2-n Connect adjacent points pairwise to form a closed curve. From the head side to the foot side, set the transparency of the color filled inside the closed curve on each plane to 30% and mark it as region G1 to G n and mark region G1 to G n After three-dimensional reconstruction, fit it in situ with the femoral model and mark it as model G.

[0080] As Figure 10 shown, mark the connections between the superior gemellus muscle and the greater trochanter of the femur on each level from the head side to the foot side as H1, H2, H3, H4 until H n and mark H1, H2, H3, H4 until H n Perform three-dimensional reconstruction and move it onto the three-dimensional femoral model to overlap them in situ, and mark it as region H. From the head side to the foot side, mark the points on each plane where the muscle contour of the gluteus medius muscle is closest to the sagittal plane passing through the midline of the human body as point H 1-1 to point H 1-n and mark the points on each plane where the muscle contour of the gluteus medius muscle is farthest from the sagittal plane passing through the midline of the human body as point H 2-1 to point H 2-n Point H 1-n and point H 2-n Divide the muscle contour into two curves. Connect H 1-n and point H 2-n with a line, marked as straight line H, and calculate the perpendicular distances from the points on these two curves to the straight line H. If there is a point where the perpendicular distances from the points on both sides to the straight line decrease or increase simultaneously, then mark this point. Finally, mark the marked points and point H 1-n and point H 2-n Connect adjacent points pairwise to form a closed curve. From the head side to the foot side, set the transparency of the color filled inside the closed curve on each plane to 30% and mark it as region H1 to H n and mark region H1 to H n After three-dimensional reconstruction, fit it in situ with the femoral model and mark it as model H.

[0081] As Figure 11 shown, mark the connections between the inferior gemellus muscle and the greater trochanter of the femur on each level from the head side to the foot side as I1, I2, I3, I4 until I n and mark I1, I2, I3, I4 until I n Perform three-dimensional reconstruction and move it onto the three-dimensional femoral model to overlap them in situ, and mark it as region I. From the head side to the foot side, mark the points on each plane where the muscle contour of the gluteus medius muscle is closest to the sagittal plane passing through the midline of the human body as point I1-1 To point I 1-n , from the head side to the foot side, mark the point farthest from the sagittal plane passing through the midline of the human body on the gluteus medius muscle contour on each plane as point I 2-1 To point I 2-n , point I 1-n And point I 2-n Divide the muscle contour into two curves. Connect I 1-n And point I 2-n , mark it as line I. Calculate the perpendicular distance from the points on these two curves to line I. If there is a point where the perpendicular distances from the points on both sides to the line decrease or increase uniformly, then mark this point. Finally, connect the marked points and point I 1-n , point I 2-n Connect adjacent two points pairwise to form a closed curve. From the head side to the foot side, set the transparency of the color filled in the closed curve on each plane to 30% and mark it as regions I1 to I n , and for regions I1 to I n After three-dimensional reconstruction, fit it in situ with the femoral model and mark it as model I.

[0082] As Figure 12 Shown, mark the connections between the piriformis muscle and the greater trochanter of the femur on each level from the head side to the foot side as Q1, Q2, Q3, Q4 until Q n , and for Q1, Q2, Q3, Q4 until Q n Perform three-dimensional reconstruction and move it onto the three-dimensional femoral model to overlap them in situ, and mark it as region Q. From the head side to the foot side, mark the point on the gluteus medius muscle contour closest to the sagittal plane passing through the midline of the human body on each plane as point Q 1-1 To point Q 1-n , from the head side to the foot side, mark the point on the gluteus medius muscle contour farthest from the sagittal plane passing through the midline of the human body on each plane as point Q 2-1 To point Q 2-n , point Q 1-n And point Q 2-n Divide the muscle contour into two curves. Connect Q 1-n And point Q 2-n , mark it as line Q. Calculate the perpendicular distance from the points on these two curves to line Q. If there is a point where the perpendicular distances from the points on both sides to the line decrease or increase uniformly, then mark this point. Finally, connect the marked points and point Q 1-n , point Q 2-n Connect adjacent two points pairwise to form a closed curve. From the head side to the foot side, set the transparency of the color filled in the closed curve on each plane to 30% and mark it as regions Q1 to Q n , and for regions Q1 to Q n After three-dimensional reconstruction, fit it in situ with the femoral model and mark it as model Q.

[0083] S6. Based on the contour calibration regions and in-situ fitting models of the respective layer muscles, obtain the highest point J of the greater trochanter, the lowest point K of the ipsilateral acetabular notch, the highest point L of the ipsilateral pelvis, and the highest point M of the acetabular rim. According to points J, K, L, and M, measure the vertical distances from the horizontal plane passing through point J to points K, L, and M to obtain points N, O, and P, which are the positions to be measured.

[0084] In a feasible implementation manner, Figure 13 It is a schematic diagram of the positions of points K, J, M, L, N, P, and O.

[0085] S7. Based on the in-situ fitting model and the positions to be measured, use the threshold segmentation and region growing methods to reconstruct the CT data to obtain measurement parameters.

[0086] S8. Measure the positions to be measured according to the measurement parameters to obtain measurement data.

[0087] Figure 14 It is a block diagram of a device for measuring the parameters of the greater trochanter of the femur based on a CT three-dimensional reconstruction image shown according to an exemplary embodiment. This device is used for a method of measuring the parameters of the greater trochanter of the femur based on a CT three-dimensional reconstruction image. Refer to Figure 14 , this device includes an extraction module 210, a reference point determination module 220, a three-dimensional processing module 230, a contour calibration module 240, a model fitting module 250, a position determination module 260, a model reconstruction module 270, and a measurement module 280. Among them,

[0088] The extraction module 210 is used to obtain CT data and model the CT data. The extraction module obtains a three-dimensional model based on the extracted pelvis, the femur on the side to be studied, and muscle data.

[0089] The reference point determination module 220 is used to determine reference points according to the three-dimensional model.

[0090] The three-dimensional processing module 230 is used to perform three-dimensional processing on the three-dimensional model according to the reference points to obtain three-dimensional processed data.

[0091] The contour calibration module 240 is used to obtain the contour calibration regions of the muscles on each CT layer according to the three-dimensional processed data.

[0092] The model fitting module 250 is used to obtain the three-dimensional reconstruction and in-situ fitting models of the contour calibration regions of the respective layer muscles according to the contour calibration regions of the muscles on each layer.

[0093] The position determination module 260 is configured to obtain the highest point J of the greater trochanter, the lowest point K of the ipsilateral acetabular notch, the highest point L of the ipsilateral pelvis, and the highest point M of the acetabular rim according to the three-dimensional reconstruction and in-situ fitting model of the contour calibration regions of the respective layer muscles. According to the points J, K, L, and M, the vertical distances between the horizontal plane passing through the point J and the points K, L, and M are measured to obtain the points N, O, and P, which are the positions to be measured.

[0094] The model reconstruction module 270 is configured to reconstruct the CT data by using a threshold segmentation and region growing method according to the in-situ fitting model and the position to be measured to obtain measurement parameters.

[0095] The measurement module 280 is configured to measure the position to be measured according to the measurement parameters to obtain measurement data.

[0096] The present invention provides a method and device for measuring the parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images. The invention can realize the rapid and accurate quantification of the parameters of the greater trochanter of the human femur, thereby providing morphological support for total hip arthroplasty. At the same time, the invention participates in the morphological clustering analysis of the greater trochanter of the femur in order to propose morphological subtypes of the greater trochanter of the femur, providing ideas for instrument design. The present invention adopts a standardized technical solution to determine the anatomical landmark points required for measuring the parameters of the greater trochanter of the femur, and proposes a measurement scheme for mapping and analyzing a large sample of medical images, solves the problems of poor data representativeness and reduces the measurement system error, etc., and realizes the efficient, convenient and accurate parameter measurement, laying a solid foundation for clinical translational application.

[0097] It can be understood that the present invention is described by the above embodiments and should not be construed as a limitation on the embodiments and the scope of the present invention. Those skilled in the art know that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teaching of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application belong to the scope protected by the present invention.

Claims

1. A method for measuring parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images, characterized in that: The method comprises: S1, acquiring CT data, modeling the CT data, and obtaining a three-dimensional model according to the extracted pelvis, the femur on the side to be studied, and muscle data; S2. Determine a reference point according to the three-dimensional model; S3. Performing three-dimensional processing on the three-dimensional model according to the reference point to obtain three-dimensional processed data; S4, obtaining the contour calibration area of ​​the muscles at each layer of CT according to the three-dimensional processed data; S5, according to the contour calibration area of ​​the muscles at each layer, obtaining a three-dimensional reconstruction and in-situ fitting model of the contour calibration area of ​​the muscles at each layer; S6, according to the three-dimensional reconstruction and in-situ fitting model of the contour calibration area of ​​the muscles at each level, the highest point J of the greater trochanter of the femur, the lowest point K of the ipsilateral acetabular notch, the highest point L of the ipsilateral pelvis and the highest point M of the acetabular edge are obtained, and according to the point J, point K, point L and point M, the vertical distances between the horizontal plane passing through point J and point K, point L and point M are measured respectively, to obtain point N, point O and point P, i.e., the position to be measured; S7, reconstructing the CT data according to the in-situ fitting model and the position to be measured by using a threshold segmentation and region growing method to obtain measurement parameters; S8. Measure the position to be measured according to the measurement parameters to obtain measurement data.

2. The method for measuring parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images according to claim 1, characterized in that: The step S2 of determining a reference point according to the three-dimensional model includes: Eight points are randomly selected on the inner side of the acetabulum, marked as points A1-A8, and spherical fitting is performed on the points A1-A8, requiring that the sum of the vertical distances from the fitted circular surface to the eight points be minimized, and the center of the sphere is marked as point B. According to the three-dimensional model, the most prominent positioning point C1 of the left anterior superior iliac spine and the most prominent positioning point C2 of the right anterior superior iliac spine are obtained.

3. The method for measuring parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images according to claim 2, characterized in that: The straight-line distance between any two points among points A1-A8 is not less than 1 cm.

4. The method for measuring parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images according to claim 2, characterized in that: The three-dimensional model is obtained based on the extracted pelvis, the femur on the side to be studied, and the muscle data, including: The femur is rotated with point B as the rotation center so that the line connecting the tip of the greater trochanter of the femur and the midpoint of the intercondylar fossa of the femur, that is, the anatomical axis of the femur, is perpendicular to the horizontal plane.

5. The method for measuring parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images according to claim 2, characterized in that: The step S3 of performing three-dimensional processing on the three-dimensional model according to the reference point includes: Model C is obtained by modeling the fibrous cartilage connecting the pubic bones on both sides at the pubic symphysis. According to the model C, the upper and lower parts of the model C are divided equally for plane positioning to obtain section C. According to section C, the straight line positioning of the extended axis dividing section C equally is obtained to obtain straight line C. According to the frontmost point of the straight line C, that is, the midpoint of the pubic symphysis, the midpoint of the pubic symphysis C3 is obtained. The pelvis is rotated with point B as the rotation center so that the plane formed by points C1, C2 and C3 is perpendicular to the horizontal plane, and the CT data is recut according to the angle after rotation.

6. The method for measuring parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images according to claim 1, characterized in that: The contour calibration area includes an area marked as area D at the connection between the gluteus medius and the greater trochanter of the femur, an area marked as area E at the connection between the gluteus minimus and the greater trochanter of the femur, an area marked as area F at the connection between the obturator internus and the greater trochanter of the femur, an area marked as area G at the connection between the obturator externus and the greater trochanter of the femur, an area marked as area H at the connection between the superior semen muscle and the greater trochanter of the femur, an area marked as area I at the connection between the inferior semen muscle and the greater trochanter of the femur, and an area marked as area Q at the connection between the piriformis muscle and the greater trochanter of the femur.

7. The method for measuring parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images according to claim 1, characterized in that: The step S4 obtains the contour calibration area of ​​muscles at each layer of CT according to the three-dimensional processed data, including: S41, recording the point on each plane where the muscle contour is closest to the sagittal plane passing through the human body midline as the first closest point, recording the point on each plane where the muscle contour is farthest from the sagittal plane passing through the human body midline as the first farthest point, marking the first closest point and the first farthest point respectively and connecting them into a straight line, and dividing the muscle contour into two curves through the straight line formed by connecting the first closest point and the first farthest point; S42, calculating the vertical distance from the points on the two curve segments to the straight line; S43. If there is a specific point that makes the vertical distance maximum or minimum, the specific point is determined as a marking point, and any two points among the marked point, the first closest point and the first farthest point are connected to form a closed curve.

8. The method for measuring parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images according to claim 7, characterized in that: The in-situ fitting models include an in-situ fitting model D for the connection between the gluteus medius and the greater trochanter of the femur, an in-situ fitting model E for the connection between the gluteus minimus and the greater trochanter of the femur, an in-situ fitting model F for the connection between the obturator internus and the greater trochanter of the femur, an in-situ fitting model G for the connection between the obturator externus and the greater trochanter of the femur, an in-situ fitting model H for the connection between the superior semen muscle and the greater trochanter of the femur, an in-situ fitting model I for the connection between the inferior semen muscle and the greater trochanter of the femur, and an in-situ fitting model Q for the connection between the piriformis muscle and the greater trochanter of the femur.

9. The method for measuring parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images according to claim 7, characterized in that: The step S43 of connecting any two points among the marked point, the first closest point and the first farthest point to form a closed curve includes: Connect any two points among the marked point, the first closest point and the first farthest point to form a closed curve, fill the closed curve with color and set the transparency to 30%.

10. A device for measuring parameters of the greater trochanter of the femur based on CT three-dimensional reconstruction images, characterized in that: include: An extraction module is used to acquire CT data and model the CT data. The extraction module obtains a three-dimensional model based on the extracted pelvis, femur and muscle data on the side to be studied; A reference point determination module, used to determine a reference point according to the three-dimensional model; A three-dimensional processing module, used for performing three-dimensional processing on the three-dimensional model according to the reference point to obtain three-dimensional processed data; A contour calibration module, used to obtain contour calibration areas of muscles at each layer of CT according to the three-dimensional processed data; A model fitting module is used to obtain a three-dimensional reconstruction and in-situ fitting model of the contour calibration area of ​​each layer of muscle according to the contour calibration area of ​​each layer of muscle; A position determination module is used to obtain the highest point J of the greater trochanter of the femur, the lowest point K of the ipsilateral acetabular notch, the highest point L of the ipsilateral pelvis and the highest point M of the acetabular edge according to the three-dimensional reconstruction and in-situ fitting model of the contour calibration area of ​​the muscles at each layer, and according to the point J, point K, point L and point M, measure the vertical distances between the horizontal plane passing through point J and point K, point L and point M respectively, to obtain point N, point O and point P, that is, the position to be measured; A model reconstruction module, used to reconstruct the CT data according to the in-situ fitting model and the position to be measured by using a threshold segmentation and region growing method to obtain measurement parameters; The measuring module is used to measure the position to be measured according to the measuring parameters to obtain measurement data.

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