Method for generating throat defect repair guide plate based on section stacking reconstruction

Abstract

The invention discloses a throat defect repair guide plate generation method based on section stacking reconstruction, and relates to the technical field of medical image processing. The problems that an existing guide plate generation method is low in standardization degree, guide plate obtaining is difficult, and consumed time is long are solved. The core of the method is that automatic conversion from the three-dimensional defect to the two-dimensional guide plate is achieved through the multi-channel slice stacking reconstruction technology and the alignment mechanism, the two-dimensional guide plate graph matched with the postoperative defect in a high-precision mode is rapidly obtained, consumed time is short, the standardization degree is high, and the guide plate two-dimensional graph is used for guiding skin flap preparation of the corresponding shape. The method is mainly used for preparing the flap for repairing the hypopharyngeal carcinoma injury.

Description

Technical Field

[0001] This invention relates to the field of medical image processing technology. Background Technology

[0002] Hypopharyngeal cancer is highly malignant and has a poor prognosis. Currently, comprehensive treatment, primarily surgery, remains the preferred method for treating hypopharyngeal cancer. Because the larynx and pharynx are two adjacent, irregular, three-dimensional anatomical structures, and the mucous membranes of the laryngeal and pharyngeal cavities are folded and irregular, and tumor invasion is highly diverse, irregular defects are often present after hypopharyngeal cancer resection. Traditional postoperative defect repair for hypopharyngeal cancer involves two methods: 1. Mucosal transposition repair using adjacent local tissues; 2. Repair using pedicled or free tissue flaps (pectoralis major myocutaneous flap, supraclavicular artery island flap, chin flap, platysma flap, free forearm flap, anterolateral thigh flap, etc.). However, these methods have the following technical limitations:

[0003] (1) Difficulty in quantifying defects: The anatomical structure of the laryngopharynx is complex, and the three-dimensional curved surface defects formed after surgery are difficult to measure accurately (the literature records that the error of traditional manual measurement is ±3.2mm).

[0004] (2) Inaccurate flap preparation: The repair range is described based on the surgeon's experience. According to the literature, 42% of cases require intraoperative adjustment of the guide plate shape.

[0005] (3) Poor functional recovery: According to literature statistics, about 40% of cases with traditional empirical suturing will experience choking after eating due to inaccurate placement of skin flap and spatial folding during repair, making it impossible to remove the tracheostomy tube.

[0006] Therefore, when repairing hypopharyngeal cancer lesions simultaneously after resection, traditional repair methods rely on empirically obtaining skin flaps of appropriate size for transplantation and suturing. Existing techniques suffer from problems such as inaccurate repair and poor functional recovery.

[0007] On the other hand, existing digital-assisted technologies include methods for accurately acquiring skin flaps preoperatively. However, these flap preparation methods rely on guides. Current guide generation methods involve 3D printing a "three-dimensional model" of the hypopharyngeal defect based on CT / MRI data before surgery, using this "three-dimensional model" as a cutting guide. This technology, from image acquisition and 3D printing to guide generation, generally takes 5-7 working days. A skin flap of the same shape is prepared based on the shape of the guide, and the prepared flap is transplanted to the defect after pharyngeal cancer resection and sutured. This can improve the accuracy of repair and functional recovery. Although the above-mentioned guide generation methods can visualize the defect through three-dimensional reconstruction, they lack an effective method to standardize the three-dimensional structure and convert it into a two-dimensional guide graphic. Furthermore, there are still problems such as difficulty in obtaining guides, long time consumption, delay in surgical timing, and high cost of 3D printing. Therefore, these problems urgently need to be solved. Summary of the Invention

[0008] To address the problems of low standardization, difficulty in obtaining guides, and long processing time in existing guide plate generation methods, this invention provides a guide plate generation method for pharyngeal defect repair based on cross-sectional stacking reconstruction.

[0009] A method for generating a guide plate for pharyngeal defect repair based on cross-sectional stacking reconstruction, the method comprising:

[0010] S1. Screening of slices from CT or MR images of the patient's larynx;

[0011] S2. Determine the cut line for each of the selected slices, wherein the cut line is a curve;

[0012] S3. Extract all excision lines and stack them from top to bottom according to the slice order corresponding to each excision line; flatten each excision line into a straight line and align all flattened straight lines.

[0013] S4. Obtain the graphic outline presented by the distribution of all flattened straight lines, and use the graphic outline as the two-dimensional guide plate graphic of the area to be repaired.

[0014] Preferably, in step S1, the criterion for screening slices in the patient's laryngeal CT or MR images is: to screen out slices with lesions.

[0015] Preferably, in step S2, the method for determining the cut line of each selected slice includes:

[0016] S21. The lesion area of ​​the selected slices is magnified locally;

[0017] S22. Stack the selected slices in order from top to bottom;

[0018] S23. Configure the same number of control points for each of the selected slices, and sort the control points on each slice in order; and take the one control point with the same sequence number selected on all slices as the reference point.

[0019] S24. Use the Bézier curve algorithm to adjust the position of the control points, draw the B-spline curve between the lesion area and the healthy area of ​​each selected slice, and align the reference points on all B-spline curves axially so that they are on the same vertical line.

[0020] The B-spline curve of each slice is used as the cut line of that slice.

[0021] Preferably, in step S23, the number of control points configured for each selected slice is: ;

[0022] When the number of control points configured for each selected slice is odd, the sequence number of the selected control points is: ;

[0023] When the number of control points configured for each selected slice is even, the sequence number of the selected control points is: or .

[0024] Preferably, in step S3, the method for flattening each cut line into a straight line is as follows:

[0025] Using the reference point on each resection line as the boundary, the resection line is divided into two curve segments. The lengths of the two curve segments are obtained, and the two curve segments are flattened into two straight lines with the reference point as the center. The lengths of the two straight lines are the same as the lengths of the two curve segments. The straight line formed by the two straight lines is the flattened straight line of the current resection line.

[0026] Preferably, in step S3, the alignment of all flattened straight lines is achieved by making the reference points of all flattened straight lines on the same vertical line, and the vertical line is perpendicular to all flattened straight lines, thus completing the alignment of all flattened straight lines.

[0027] Preferably, in step S4, the graphic outline presented by all the flattened straight lines is as follows:

[0028] Connect the endpoints of all straight lines on the same side in sequence to form the outer outline of the graphic.

[0029] A device for generating a guide plate for pharyngeal defect repair based on three-dimensional reconstruction includes a storage device, a processor, and a computer program stored in the storage device and executable on the processor. The processor executes the computer program to implement the method for generating a guide plate for pharyngeal defect repair based on cross-section stacking reconstruction as described above.

[0030] A computer-readable storage device stores a computer program that, when executed, implements the method for generating a guide plate for pharyngeal defect repair based on cross-section stacking reconstruction.

[0031] A computer program product includes a computer program that, when executed by a processor, implements the method for generating a guide plate for pharyngeal defect repair based on cross-section stacking reconstruction as described above.

[0032] The beneficial effects of this invention are as follows: The core of this invention lies in the automated conversion of three-dimensional defects to two-dimensional guides through multi-channel slice stacking reconstruction technology and alignment mechanisms. This allows for the rapid acquisition of two-dimensional guide graphics that are highly accurate in matching the postoperative defect, with short processing time and high standardization. Furthermore, the two-dimensional graphics of the guides guide the preparation of flaps of corresponding shapes, further solving the problem of inaccurate flap shape matching in traditional repair surgery. Combined with a clinically validated pedicled island flap repair scheme, this provides a precise and widely applicable repair method. Attached Figure Description

[0033] Figure 1 This is a schematic diagram illustrating the principle of the method for generating a guide plate for pharyngeal defect repair based on cross-sectional stacking reconstruction as described in this invention.

[0034] Figure 2 This is a partial magnification and a schematic diagram of the B-spline curve drawing boundary;

[0035] Figure 3 This is a schematic diagram of the alignment mechanism using control point P5 or control point P6 on two slices as reference points;

[0036] Figure 4 It is a two-dimensional schematic diagram of all the straight lines after being flattened. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0039] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0040] Specific Implementation Method 1: Combination Figure 1 and Figure 4 As shown in this embodiment, the method for generating a guide plate for pharyngeal defect repair based on cross-sectional stacking reconstruction includes:

[0041] S1. Screening of slides in CT or MR images of the patient's larynx; in specific applications, screening out slides with lesions;

[0042] S2. Determine the cut line for each of the selected slices, wherein the cut line is a curve; each slice corresponds to a cut surface;

[0043] S3. Extract all excision lines and stack them from top to bottom according to the slice order corresponding to each excision line; flatten each excision line into a straight line and align all flattened straight lines.

[0044] S4. Obtain the graphic outline presented by the distribution of all flattened straight lines, and use the graphic outline as the two-dimensional guide plate graphic of the area to be repaired. Figure 4The figure shows the distance d between two adjacent flattened straight lines, which corresponds to the distance between the scanning planes of two adjacent slices.

[0045] In this preferred embodiment, the multi-channel slice stacking reconstruction technology and alignment mechanism are used to realize the automated conversion of three-dimensional defects into two-dimensional guides, quickly obtain two-dimensional guide patterns that are highly accurate to the postoperative defects, with short processing time and high standardization, and use the two-dimensional guide patterns to guide flap preparation to obtain two-dimensional guides made from flaps.

[0046] See further Figure 2 In step S2, determining the method for implementing the cut line of each selected slice includes:

[0047] S21. The lesion area of ​​the selected slices is magnified locally;

[0048] S22. Stack the selected slices in order from top to bottom;

[0049] S23. Configure the same number of control points for each of the selected slices, and sort the control points on each slice in sequence; and use one control point with the same sequence number selected on all slices as the reference point; specifically,

[0050] The number of control points configured for each selected slice is ;

[0051] When the number of control points configured for each selected slice is odd, the sequence number of the selected control points is: ;

[0052] When the number of control points configured for each selected slice is even, the sequence number of the selected control points is: or ;

[0053] S24. Use the Bézier curve algorithm to adjust the position of the control points, draw the B-spline curve between the lesion area and the healthy area of ​​each selected slice, and align the reference points on all B-spline curves axially so that they are on the same vertical line; use the B-spline curve of each slice as the excision line of that slice.

[0054] Figure 2 In the diagram, the large black area to the right of the B-spline curve represents the tracheal cavity of the patient, the gray tissue to the right of the curve represents the laryngeal tumor, and the gray area to the left represents healthy laryngeal tissue. Figure 3 The middle gives When the value is 10, the control points on each slice are P1 to P10, and an alignment mechanism with control point P5 or P6 as the reference point is given.

[0055] In this preferred embodiment, during the process of determining the cut lines of each slice using the above method, the cut position of each image slice is precisely controlled, providing a data basis for the accuracy of the subsequently generated more accurate guide plate shape. The B-spline curve control point alignment mechanism can align each independent cut line in the vertical direction of space, making the subsequently generated guide plate shape more accurate.

[0056] Furthermore, in step S3, the method for flattening each cut line into a straight line is as follows:

[0057] Using a reference point on each resection line as a boundary, the resection line is divided into two curve segments. The lengths of these two curve segments are obtained, and each curve segment is flattened into two straight lines centered on the reference point. The lengths of the two straight lines are the same as the lengths of the two curve segments. The straight line formed by the two straight lines is used as the flattened straight line of the current resection line. This process ensures that the length of the resection line at the corresponding position on the subsequently generated two-dimensional guide plate is consistent with the actual wound length, thereby achieving a high degree of lateral size matching between the guide plate and the wound.

[0058] Furthermore, in step S3, aligning all flattened straight lines is achieved by ensuring that the reference points of all flattened straight lines are on the same vertical line, and that this vertical line is perpendicular to all flattened straight lines, thus completing the alignment of all flattened straight lines. This process ensures that different excision lines can be aligned along the lines formed by the reference points, thereby achieving a high degree of shape matching between the guide plate and the wound surface.

[0059] Further, see Figure 4 In step S4, the outline of the graphic presented by all the flattened straight lines is as follows:

[0060] Connect the endpoints of all straight lines on the same side in sequence to form the outer outline of the graphic.

[0061] Specific Implementation Method 2: A device for generating a guide plate for pharyngeal defect repair based on three-dimensional reconstruction, comprising a storage device, a processor, and a computer program stored in the storage device and executable on the processor, characterized in that the processor executes the computer program to implement the method for generating a guide plate for pharyngeal defect repair based on cross-sectional stacking reconstruction as described in Specific Implementation Method 1. Specific Embodiment 3: A computer-readable storage device storing a computer program, characterized in that, when the computer program is executed, it implements the method for generating a guide plate for pharyngeal defect repair based on cross-section stacking reconstruction as described in Specific Embodiment 1. Specific Implementation Method Four: A computer program product, comprising a computer program that, when executed by a processor, implements the method for generating a guide plate for pharyngeal defect repair based on cross-section stacking reconstruction as described in Specific Implementation Method One.

[0062] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A method for generating a guide plate for pharyngeal defect repair based on cross-sectional stacking reconstruction, characterized in that, The method includes: S1. Screening of slices from CT or MR images of the patient's larynx; S2. Determine the cut line for each of the selected slices, wherein the cut line is a curve; S3. Extract all excision lines and stack them from top to bottom according to the slice order corresponding to each excision line; flatten each excision line into a straight line and align all flattened straight lines. S4. Obtain the graphic outline presented by the distribution of all flattened straight lines, and use the graphic outline as the two-dimensional guide plate graphic of the area to be repaired.

2. The method for generating a guide plate for pharyngeal defect repair based on cross-sectional stacking reconstruction according to claim 1, characterized in that, In step S1, the criteria for screening slices in the patient's laryngeal CT or MR images are: to screen out slices with lesions.

3. The method for generating a guide plate for pharyngeal defect repair based on cross-sectional stacking reconstruction according to claim 1, characterized in that, In step S2, determining the method for implementing the cut line of each selected slice includes: S21. The lesion area of ​​the selected slices is magnified locally; S22. Stack the selected slices in order from top to bottom; S23. Configure the same number of control points for each of the selected slices, and sort the control points on each slice in order; and take the one control point with the same sequence number selected on all slices as the reference point. S24. Use the Bézier curve algorithm to adjust the position of the control points, draw the B-spline curve between the lesion area and the healthy area of ​​each selected slice, and align the reference points on all B-spline curves axially so that they are on the same vertical line. The B-spline curve of each slice is used as the cut line of that slice.

4. The method for generating a guide plate for pharyngeal defect repair based on cross-sectional stacking reconstruction according to claim 3, characterized in that, In step S23, the number of control points configured for each selected slice is: ; When the number of control points configured for each selected slice is odd, the sequence number of the selected control points is: ; When the number of control points configured for each selected slice is even, the sequence number of the selected control points is: or .

5. The method for generating a guide plate for pharyngeal defect repair based on cross-sectional stacking reconstruction according to claim 3, characterized in that, In step S3, the method for flattening each cut line into a straight line is as follows: Using the reference point on each resection line as the boundary, the resection line is divided into two curve segments. The lengths of the two curve segments are obtained, and the two curve segments are flattened into two straight lines with the reference point as the center. The lengths of the two straight lines are the same as the lengths of the two curve segments. The straight line formed by the two straight lines is the flattened straight line of the current resection line.

6. The method for generating a guide plate for pharyngeal defect repair based on cross-sectional stacking reconstruction according to claim 5, characterized in that, In step S3, the method to align all flattened lines is to make the reference points of all flattened lines on the same vertical line, and the vertical line is perpendicular to all flattened lines, thus completing the alignment of all flattened lines.

7. The method for generating a guide plate for pharyngeal defect repair based on cross-sectional stacking reconstruction according to claim 1, characterized in that, In step S4, the outline of the graphic presented by all the flattened straight lines is as follows: Connect the endpoints of all straight lines on the same side in sequence to form the outer outline of the graphic.

8. A device for generating a guide plate for pharyngeal defect repair based on three-dimensional reconstruction, comprising a storage device, a processor, and a computer program stored in the storage device and executable on the processor, characterized in that, The processor executes a computer program to implement the method for generating a guide plate for pharyngeal defect repair based on cross-section stacking reconstruction as described in any one of claims 1 to 7.

9. A computer-readable storage device storing a computer program, characterized in that, When the computer program is executed, it implements the method for generating a guide plate for pharyngeal defect repair based on cross-section stacking reconstruction as described in any one of claims 1 to 7.

10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the method for generating a guide plate for pharyngeal defect repair based on cross-section stacking reconstruction as described in claims 1 to 7.

Images