Three-dimensional eye burst measurement method based on skull stable reference surface, computer readable storage medium and electronic equipment

Abstract

The invention discloses a three-dimensional eye burst measurement method based on a skull stable reference plane, a computer readable storage medium and electronic equipment. The method comprises the following steps: constructing a Frankport plane according to preoperative skull three-dimensional CT (Computed Tomography) image data; marking symmetrical stable anatomical mark points on two sides of the skull, establishing a preoperative skull stable reference plane MTM vertical to the Frankport plane based on a connecting line of the stable anatomical mark points, and taking an intersection point of the MTM and the parietal bone as a preoperative parietal skull bony mark point T; calculating the preoperative ocular protrusion; carrying out rigid body registration on the postoperative and preoperative three-dimensional CT images of the skull; the position of the preoperative skull crest bony mark point T after registration is determined, and a postoperative skull stable reference plane MTM'is reconstructed by combining symmetrical stable anatomical mark points on the two sides of the skull identical to the preoperative skull crest bony mark point T; calculating the postoperative eye protrusion degree; and calculating the difference value of the ocular protrusion before and after the operation to obtain the variation of the ocular protrusion. The method has the advantages that the method supports preoperative and postoperative consistent measurement, and the eyeshade degree is accurately quantified in a three-dimensional space.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical image processing and eye protrusion analysis, and in particular, to a three-dimensional eye protrusion measurement method based on a stable reference surface of the skull, a computer readable storage medium and an electronic device. BACKGROUND

[0002] Eye protrusion refers to the degree of protrusion of the anterior pole of the eyeball (i.e., the vertex of the cornea) relative to the anterior structure of the orbital bone, which is a key spatial parameter in eye clinical anatomy and is widely used in the diagnosis, evaluation and efficacy judgment of diseases such as thyroid-related eye disease, craniofacial dysplasia (such as Crouzon syndrome), orbital tumor, orbital trauma and plastic reconstruction. Abnormal eyeball position is often accompanied by orbital bone dysplasia, orbital bone structure displacement, insufficient or excessive orbital volume, which can easily lead to eyeball protrusion or retraction, exposure or functional vision problems, so objective and accurate evaluation of eye protrusion has important clinical significance.

[0003] The current mainstream measurement methods include two categories: (1) body surface Hertel exophthalmometer: the base of the instrument is placed on the bilateral lateral orbital margin, and the distance value is read by aligning the mirror with the vertex of the cornea. This method is simple and fast, and can be used for routine screening and follow-up in outpatient clinics, but its accuracy is limited by the operation experience, patient head position, soft tissue state and orbital margin anatomical integrity, and its repeatability and consistency are poor. In addition, for patients with orbital bone spatial position changes or severe deformities, this method often fails to position the reference point correctly, resulting in measurement failure. (2) Image-assisted two-dimensional measurement: the vertical distance of the vertex of the cornea relative to the orbital margin connecting line is measured in the axial or sagittal image to obtain the quantitative value of eye protrusion. This method is more objective than body surface measurement and is suitable for preoperative evaluation of patients who cannot be measured by body surface. However, its core limitation is that the reference structure (such as the orbital margin) will shift significantly after periorbital trauma or periorbital osteotomy, affecting the consistency of the measurement; and when the image is tilted or the head position is unstable, two-dimensional cross-sectional measurement can easily produce errors.

[0004] Based on the above, the existing eye protrusion measurement methods have the following shortcomings: lack of uniform and stable measurement reference structure before and after surgery, especially when the periorbital bone structure changes, the consistency of the measurement reference cannot be maintained; the measurement method is mainly based on two-dimensional images, which cannot fully reflect the three-dimensional spatial relationship between the eyeball and the periorbital bone, the precision is limited by the image angle and layer, and the operation depends on subjective judgment, with poor stability and repeatability; only the projection position of the eyeball relative to the ear canal is measured, which cannot truly reflect the degree of protrusion relative to the orbital margin, and the clinical interpretation is limited. Therefore, it needs to be improved.

[0005] The statements herein merely provide background technology related to the present application, and do not necessarily constitute the prior art. SUMMARY

[0006] Based on the foregoing technical problems, the purpose of the present application is to provide a three-dimensional enophthalmos measurement method based on a stable reference surface of the skull, a computer readable storage medium and an electronic device, which constructs a stable measurement reference surface based on the stability of the skull before and after the operation, thereby ensuring a unified and stable measurement reference structure before and after the operation, avoiding the influence of changes in the spatial position of the bony structure on the measurement, and especially excluding the interference of orbital periosteal displacement, thereby ensuring the reliability and repeatability of the data.

[0007] In order to achieve the above purpose, the present application realizes the following technical solutions:

[0008] A three-dimensional enophthalmos measurement method based on a stable reference surface of the skull, comprising:

[0009] Preoperative enophthalmos measurement: constructing a Frankfort plane according to the preoperative head three-dimensional CT image data of the subject; labeling the stable anatomic landmark points on both sides of the skull symmetrically, and establishing a preoperative skull stable reference surface MTM perpendicular to the Frankfort plane based on the connecting line of the stable anatomic landmark points on both sides of the skull symmetrically, determining the intersection of the plane and the parietal bone, and taking the intersection as the preoperative parietal bony landmark point T; calculating the enophthalmos of the left and right sides before the operation;

[0010] Postoperative enophthalmos measurement: rigidly registering the postoperative head three-dimensional CT image with the preoperative head three-dimensional CT image; determining the position of the preoperative parietal bony landmark point T in the postoperative head three-dimensional CT image after registration, and combining the stable anatomic landmark points on both sides of the skull symmetrically before and after the operation to reconstruct the postoperative skull stable reference surface MTM' consistent with the preoperative space; calculating the enophthalmos of the left and right sides after the operation in the same way as the preoperative enophthalmos calculation;

[0011] Enophthalmos change amount calculation: calculating the enophthalmos difference of the left and right sides before and after the operation to obtain the enophthalmos change amount of the left and right sides.

[0012] Optionally, in the preoperative enophthalmos measurement, when acquiring the preoperative head three-dimensional CT image data of the subject, the scanning needs to cover the complete orbital region, the temporal bone region and the parietal region.

[0013] Optionally, in the preoperative enophthalmos measurement, constructing the preoperative skull stable reference surface MTM comprises:

[0014] Based on the preoperative head three-dimensional CT image data of the subject, the bilateral upper points of the ear gate and any lower orbital rim point are labeled, and the Frankfort plane is constructed with the above three points, which is a horizontal reference surface in the middle of the skull; a line is established between the symmetrical stable anatomical landmark points on both sides of the skull, and a three-dimensional coordinate system is established with the midpoint of the line as the origin; a preoperative skull stable reference surface MTM perpendicular to the Frankfort plane is established based on the line connecting the symmetrical stable anatomical landmark points on both sides of the skull, the intersection of the preoperative skull stable reference surface MTM and the parietal bone is determined, and the intersection is taken as the preoperative parietal bone landmark point T, which is taken as the landmark point of the postoperative skull stable reference surface MTM'.

[0015] Optionally, in the postoperative eye protrusion measurement, when acquiring the postoperative head three-dimensional CT image data of the subject, the complete orbital region, temporal bone region and skull top region need to be covered.

[0016] Optionally, in the postoperative eye protrusion measurement, reconstructing the postoperative skull stable reference surface MTM' comprises:

[0017] In the postoperative head three-dimensional CT image, the same symmetrical stable anatomical landmark points on both sides of the skull as the preoperative ones are labeled, and the postoperative head three-dimensional CT image is rigidly registered based on the skull base, ear gate and adjacent skull structure, so that it is spatially aligned with the preoperative head three-dimensional CT image; in the registered postoperative head three-dimensional CT image, the preoperative parietal bone landmark point T is accurately restored to the corresponding postoperative parietal bone landmark point T' in the postoperative head three-dimensional CT image based on the position information of the preoperative parietal bone landmark point T recorded preoperatively; the postoperative skull stable reference surface MTM' consistent with the preoperative space is reconstructed based on the postoperative parietal bone landmark point T' and the symmetrical stable anatomical landmark points on both sides of the skull.

[0018] Optionally, calculating the left and right eye protrusions comprises:

[0019] Calibrating the left and right corneal vertexes and a plurality of bony orbital rim points, measuring the vertical distance of the left and right corneal vertexes and the plurality of bony orbital rim points relative to the preoperative skull stable reference surface MTM or the postoperative skull stable reference surface MTM', and calculating the left and right eye protrusions preoperatively or postoperatively.

[0020] Optionally, calculating the preoperative eye protrusion measurement value comprises:

[0021] In the preoperative head three-dimensional CT image, the bilateral corneal vertexes, bilateral upper orbital rim points, bilateral lower orbital rim points and bilateral lateral orbital rim points are labeled; the distances of the above-mentioned bilateral anatomical landmark points in space projected to the preoperative skull stable reference surface MTM along the normal direction of the preoperative skull stable reference surface MTM are calculated, the relevant parameters are recorded, and the difference between the average of the projection distances of the preoperative left and right corneal vertexes and the projection distances of the ipsilateral upper, lower and lateral rims is calculated as the preoperative eye protrusion measurement value of the left and right sides.

[0022] The postoperative eye protrusion measurement value comprises:

[0023] The same bilateral anatomical landmark points in the postoperative head three-dimensional CT image as in the preoperative head three-dimensional CT image are labeled, the distance of each anatomical landmark point in the postoperative bilateral spatial position change from the normal direction of the reconstructed postoperative skull stable reference surface MTM' to the plane is calculated, the relevant parameters are recorded, and the difference between the postoperative projection distance of each corneal vertex and the average projection distance of the ipsilateral superior, inferior and lateral orbital margins is calculated as the postoperative eye protrusion measurement value of the left and right sides.

[0024] Optionally, the two sides of the skull symmetrical stable anatomical landmark points include at least one of the bilateral mastoid points, bilateral soft round hole points, bilateral spinous hole points and bilateral upper ear gate points.

[0025] Optionally, a computer readable storage medium has a computer program stored thereon, and the computer program is executed by a processor to implement the three-dimensional eye protrusion measurement method based on the skull stable reference surface.

[0026] Optionally, an electronic device includes a processor and a memory, and the memory has a computer program stored thereon, and the computer program is executed by the processor to implement the three-dimensional eye protrusion measurement method based on the skull stable reference surface.

[0027] Compared with the prior art, the present application has the following advantages:

[0028] In the three-dimensional eye protrusion measurement method based on the skull stable reference surface, the preoperative skull stable reference surface MTM and the preoperative skull vertex bony landmark point T are defined before operation, and the postoperative skull two sides symmetrical stable anatomical landmark points and the postoperative skull vertex bony landmark point T' are coincided with the same anatomical position points before operation through rigid registration, so that the postoperative skull stable reference surface MTM' is coincided with the preoperative skull stable reference surface MTM, so that the measurement reference plane before and after operation is kept consistent, the consistency of the measurement reference is ensured, and the stability and reliability of the data are ensured. The method has essential difference from various measurement methods in previous researches, and has great innovation.

[0029] Further, in the present application, the bilateral corneal vertex and a plurality of bony orbital margin points are calibrated when the eye protrusion is calculated, and the vertical distance relative to the preoperative skull stable reference surface MTM or the postoperative skull stable reference surface MTM' is measured to calculate the preoperative / postoperative eye protrusion. This way can accurately quantify the exophthalmos in three-dimensional space, can truly reflect the protrusion degree relative to the orbital margin, and has strong clinical interpretation. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the present application, the drawings required to be used in the description will be briefly introduced as follows. Obviously, the drawings in the following description are one embodiment of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0031] Figure 1 A flow chart of a three-dimensional eye protrusion measurement method based on a skull stable reference surface according to the present application;

[0032] Figure 2 A schematic diagram of preoperative eye protrusion measurement according to the present application;

[0033] Figure 3 A schematic diagram of postoperative eye protrusion measurement according to the present application. DETAILED DESCRIPTION

[0034] The three-dimensional eye protrusion measurement method based on a skull stable reference surface, the computer readable storage medium and the electronic device according to the present application will be further described in detail below in combination with the drawings and specific embodiments. The advantages and features of the present application will be more apparent according to the following description. It should be noted that the drawings are greatly simplified and all use non-precise proportions, only to facilitate, clear and assist in the purpose of explaining the embodiments of the present application. In order to make the purpose, features and advantages of the present application more apparent and easy to understand, please refer to the drawings. It should be noted that the structure, proportion, size and the like shown in the drawings attached to the present specification are only used to cooperate with the content disclosed in the specification, so that those skilled in the art can understand and read, and not to limit the defined conditions for the implementation of the present application, so it does not have the technical meaning in essence, any modification of structure, change of proportion relationship or adjustment of size, without affecting the effect and purpose that can be achieved by the present application, should still fall within the scope of the technical content disclosed by the present application. The following examples will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present application. These are within the scope of protection of the present application.

[0035] As mentioned above, in practical applications, neither the Hertel exophthalmometer based on the body surface nor image-assisted two-dimensional measurements can meet the actual needs. For example, in two-dimensional measurement methods using the bilateral ear canal bone structures as a reference, computer software can be used to adjust the image posture, construct a horizontal baseline, and measure the vertical distance from the eyeball to this line to achieve quantitative analysis of exophthalmos. This approach has certain applicability in specific scenarios, but still has significant limitations: image tilt or incorrect head position can easily introduce errors, although posture correction can partially improve this, but the process is cumbersome and has limited stability; this method cannot fully reflect the three-dimensional relationship between the eyeball and the periorbital bony structures, lacking the ability to restore true space; and it only measures the linear distance from the eyeball to the ear canal, failing to objectively quantify the degree of eyeball protrusion relative to the orbital rim, thus limiting its clinical interpretability; when assessing the preoperative and postoperative exophthalmos of major surgeries such as syndromic craniosynostosis, due to the overall displacement of the facial bone mass, the horizontal baseline constructed by this method before and after surgery also shifts, failing to accurately reflect the actual situation of exophthalmos.

[0036] On the other hand, two-dimensional measurement also has the following disadvantages: ① Due to differences in CT scan baseline, slice thickness, and slice interval, the image cannot guarantee a completely horizontal or vertical position. When the image is tilted or the head position is unstable, two-dimensional cross-sectional measurements are prone to errors. In practical applications, even if a relatively stable horizontal head position is obtained through repeated baseline adjustments, its accuracy is still insufficient, and the operation process is cumbersome. ② Eye exophthalmos presents a three-dimensional representation, reflecting the degree of protrusion of the eyeball relative to the periorbital region. Two-dimensional measurement cannot simultaneously take into account multiple structures and layers of the eyeball and periorbital region. Multiple scans of images at different angles or layers are required to obtain more comprehensive information, but even so, it is difficult to completely restore its true three-dimensional structure. ③ Two-dimensional measurement can only measure the distance from the eyeball to the baseline of the bilateral auricular openings. In essence, it only reflects the spatial position of the eyeball relative to the auricular openings and does not reflect the magnitude of eye exophthalmos.

[0037] Furthermore, in practical applications, some major facial surgeries or severe fractures present a challenge: spatial displacement of all or part of the bones around the orbit, with only the skull base remaining stable. In this situation, traditional measurement methods based on the outer edge of the orbit are completely ineffective, and two-dimensional measurement methods cannot measure pre- and post-operative differences. This is because, in two-dimensional measurement methods, after surgery or trauma causes displacement of the entire midfacial bone mass, the hard palate's position relative to the skull shifts. The spatial position of the hard palate changes before and after surgery; therefore, if the hard palate is still used as a horizontal plane for distance measurement, human error will occur. However, existing research has not addressed or recognized this problem, nor has it undertaken technical improvements to address it.

[0038] The research team of this invention recognized the above problems and proposed a three-dimensional ocular protrusion measurement method based on a stable skull reference plane (see [link to invention]). Figure 1 This method measures exophthalmos based on a three-dimensional structure. Relevant anatomical points on the Frankford plane are marked on the 3D reconstructed model, and periocular and ocular protrusion points can also be marked. The operation is simple, standardized, and easily accepted and promoted. Simultaneously, this invention establishes a preoperative skull stability reference plane (MTM) based on the Frankford plane and connecting symmetrical stable anatomical landmarks on both sides of the skull. Postoperatively, through rigid registration, and by aligning the preoperative bony landmark T on the top of the skull and symmetrical stable anatomical landmarks on both sides of the skull with the same preoperative anatomical location, the postoperative skull stability reference plane MTM' coincides with the preoperative skull stability reference plane MTM, thus ensuring consistency between the preoperative and postoperative measurement reference planes. This method avoids the influence of changes in the spatial position of bony structures on the measurement, provides a unified and stable three-dimensional reference benchmark, and offers high data reliability and comprehensive measurements. This method is a novel measurement method based on the stable structure of the skull, which can eliminate interference from periorbital bone displacement, support consistent preoperative and postoperative measurements, and accurately quantify exophthalmos in three-dimensional space. It can overcome the shortcomings of traditional measurement methods that all periorbital bones become ineffective after major craniofacial surgery.

[0039] Specifically, such as Figure 1 As shown, this invention provides a three-dimensional ocular exotropia measurement method based on a skull stability reference plane. The method includes: S100, preoperative ocular exotropia measurement: Based on the preoperative three-dimensional CT image data of the subject's skull, a Frankfort plane (hereinafter referred to as the FP plane) is constructed; symmetrical stable anatomical landmarks on both sides of the skull are marked, and a reference plane perpendicular to the Frankfort plane is established based on the line connecting the symmetrical stable anatomical landmarks on both sides of the skull, which is defined as the preoperative skull stability reference plane MTM; the intersection of this plane and the parietal bone is determined, and this intersection is used as the preoperative cranial parietal bony landmark T; the preoperative ocular exotropia on the left and right sides is calculated.

[0040] As described above, this invention establishes a preoperative skull stability reference plane (MTM) based on the Frankford plane and the connection between symmetrical stable anatomical landmarks on both sides of the skull. In practical applications, the Frankford plane is an important plane in craniofacial measurements. Unlike custom-defined hard palate planes in two-dimensional measurements, the Frankford plane is the fundamental plane for craniofacial measurement data, offering high data reliability. However, previous studies have not applied it to the measurement of eye protrusion. This invention, by establishing a bilateral stable anatomical landmark plane (bilateral mastoid point plane) perpendicular to the Frankford plane, can better integrate with previous data, thus facilitating data acceptance and use.

[0041] Specifically, the preoperative ocular protrusion measurement includes: S101, acquiring preoperative skull images of the subject; S102, constructing a preoperative skull stability reference plane (MTM); and S103, calculating the preoperative ocular protrusion measurement value.

[0042] S101. Acquiring preoperative head images of the subject: The head images are three-dimensional CT images of the head. The preoperative three-dimensional CT images of the head are acquired before the craniofacial surgical intervention, and the scan must cover the entire orbital region, temporal bone region, and cranial vertex region to ensure that stable anatomical landmarks are clearly visible and accurately located in the images.

[0043] S102. Construct the preoperative skull stabilization reference plane (MTM): (e.g.) Figure 2 As shown, based on the preoperative three-dimensional CT image data of the subject's head, point P on the left ear canal is marked. l (x1, y1, z1), Point P on the right ear canal r (x2,y2,z2), and B(x) on either side of the infraorbital margin. b ,y b ,z b Based on the bilateral auricular points P l P r Construct a Frankfort plane with point B on either side of the infraorbital margin, the Frankfort plane being a horizontal reference plane for the middle of the skull.

[0044] A line is established between symmetrical stable anatomical landmarks on both sides of the skull, and a three-dimensional coordinate system is established with the midpoint of the line as the origin. Based on the line connecting the symmetrical stable anatomical landmarks on both sides of the skull, a preoperative skull stability reference plane MTM perpendicular to the Frankfort plane is established. The intersection of the preoperative skull stability reference plane MTM and the parietal bone is determined, and this intersection is taken as the preoperative cranial parietal bony landmark T. The preoperative cranial parietal bony landmark T is used as the landmark of the postoperative skull stability reference plane MTM'.

[0045] In practical applications, stable anatomical landmarks symmetrical on both sides of the skull include bilateral soft foramina, bilateral spinous foramina, bilateral supraorbital points, and bilateral mastoid points. Among these, the bilateral mastoid points are iconic structures of the skull base, located on the body surface and easily distinguishable from surrounding anatomical structures. Their prominent protrusions are easy to mark. Furthermore, the method of this invention focuses on measuring exophthalmos after movement of periorbital bone structures, while the mastoid structures remain stable after periorbital bone movement, thus ensuring measurement stability. Therefore, this embodiment uses the bilateral mastoid points as stable anatomical landmarks symmetrical on both sides of the skull for illustration.

[0046] like Figure 2 As shown, in this embodiment, the left nipple point M is marked. l (x ml ,y ml ,z ml) and right mastoid point M r (x mr ,y mr ,z mr Establish a three-dimensional coordinate system with the midpoint of this line as the origin O, connecting the two mastoid processes (M). l M r Based on the connecting lines, a reference plane orthogonal to the Frankfort plane is constructed, and this reference plane is defined as the preoperative cranial stability reference plane (MTM). A preoperative cranial parietal bony landmark T(x) is selected at the intersection of the preoperative cranial stability reference plane MTM and the parietal surface. t ,y t ,z t The intersection of these points serves as a landmark for the postoperative skull stabilization reference plane, MTM'. In practical applications, the highest point of the skull vertex at the intersection can be selected as the preoperative bony landmark T(x). t ,y t ,z t This is to facilitate later localization. In one embodiment, the preoperative bony landmark T(x) on the top of the skull is used. t ,y t ,z t The line connecting the origin O and the bilateral mastoid process M l M r The lines connecting them are perpendicular to each other to facilitate later positioning.

[0047] S103. Calculation of Preoperative Eye Protrusion Measurements: In this invention, when calculating preoperative eye protrusion, the left and right corneal apexes and multiple bony orbital rim points are marked, and their vertical distances relative to the preoperative skull stability reference plane (MTM) are measured to calculate the preoperative left and right eye protrusion. This invention is based on preoperative three-dimensional CT images of the skull, which can simultaneously mark the eyeball and the four orbital rims, thereby measuring the distances from each to the preoperative skull stability reference plane (MTM), i.e., the baseline plane. The eyeball's protrusion relative to the orbital rim is calculated through an algorithm, which is scientific and reflects clinical reality.

[0048] Specifically, such as Figure 2 As shown, the bilateral corneal apex K is marked in the preoperative three-dimensional CT image of the skull. l (x kl ,y kl ,z kl ), K r (x kr ,y kr ,z kr Bilateral supraorbital margin points S l (x sl ,y sl ,z sl ), S r (x sr ,y sr ,zsr ), bilateral infraorbital margin point B l (x bl ,y bl ,z bl B r (x br ,y br ,z br ) and bilateral lateral orbital margin points G l (x gl ,y gl ,z gl ), G r (x gr ,y gr ,z gr Feature points with clear edges, easy to locate, and distinct bony landmarks are selected. The distance d from each of these bilateral anatomical landmarks to the preoperative skull stability reference plane (MTM) is calculated by projecting it into space along the normal direction of the MTM. kl d kr d sl d sr d bl d br d gl d gr , where d kl Point K l The distance projected onto the MTM (Mean Transcranial Matrix) normal direction of the preoperative skull stability reference plane is recorded, and the meaning of other distances is deduced similarly. Relevant parameters are recorded, and the difference between the preoperative corneal apex projection distance on each side and the average projection distances of the ipsilateral superior, inferior, and lateral orbital margins is calculated as the preoperative ocular protrusion measurement values ​​for the left and right sides.

[0049] Preoperative left eye protrusion Q l : D l ={d sl ,d bl ,d gl},

[0050] Preoperative right eye protrusion Q r : D r ={d sr ,d br ,d gr},

[0051] Where n is the number of feature points on each side that are clearly defined, easy to locate, and have clear bony landmarks. In this embodiment, n = 3.

[0052] S200. Postoperative ocular exotropia measurement: Rigid body registration was performed between the postoperative 3D CT image of the skull and the preoperative 3D CT image of the skull; the position coordinates of the preoperative cranial bony landmark T in the registered postoperative 3D CT image of the skull were determined; combined with the stable anatomical landmarks (bilateral mastoid points) on both sides of the skull that are the same as before the operation, the postoperative skull stability reference plane MTM' consistent with the preoperative space was reconstructed; the ocular exotropia was calculated on the left and right sides after the operation using the same method as before the operation.

[0053] Specifically, the postoperative exophthalmos measurement includes: S201, acquiring postoperative skull images of the subject; S202, reconstructing the postoperative skull stability reference plane MTM'; S203, calculating the postoperative exophthalmos measurement value.

[0054] S201. Acquiring postoperative skull images of the subject: The skull images are postoperative three-dimensional CT image data of the skull, i.e., three-dimensional reconstructed CT image data. The postoperative three-dimensional CT images of the skull are acquired during the postoperative recovery period, and the scan must cover the complete orbital region, temporal bone region, and cranial vertex region to ensure that anatomical landmarks are clearly visible and accurately located in the images.

[0055] S202, Reconstructing the Postoperative Skull Stability Reference Plane (MTM): In the postoperative 3D CT image of the skull, symmetrical stable anatomical landmarks on both sides of the skull, identical to those before surgery, are marked. Rigid body registration is then performed on the postoperative 3D CT image of the skull based on the skull base, auricular region, and adjacent skull structures, aligning it spatially with the preoperative 3D CT image of the skull. For example... Figure 3 As shown, in this embodiment, the stable anatomical landmarks symmetrical on both sides of the skull, identical to those before surgery, are the bilateral mastoid points M. l '(x ml ',y ml ',z ml '), M r '(x mr ',y mr ',z mr ').

[0056] In the registered postoperative three-dimensional CT images of the skull, the spatial coordinates T(x) are based on the preoperatively recorded location information of the preoperative bony landmark T on the top of the skull. t ,y t ,z t ), accurately restore the preoperative cranial parietal bony landmark T to the postoperative cranial parietal bony landmark T'(x) in the postoperative three-dimensional CT image of the skull. t ',y t ',z t Based on postoperative cranial bony landmarks T'(x) t ',y t ',z t ') and postoperative bilateral mastoid points M l'、M r 'To jointly reconstruct the postoperative skull stability reference plane (MTM) that is consistent with the preoperative space'.

[0057] S203. Calculate postoperative eye protrusion measurement: In this invention, when calculating postoperative eye protrusion, the left and right corneal apexes and multiple bony orbital rim points that are the same as those in the preoperative skull image are marked, and their vertical distances relative to the postoperative skull stability reference plane MTM' are measured to calculate the postoperative left and right eye protrusion.

[0058] Specifically, such as Figure 3 As shown, the same bilateral anatomical landmarks as those in the preoperative 3D CT images of the head are marked in the postoperative 3D CT images, such as the bilateral corneal apex K. l '(x kl ,y kl ,z kl ), K r '(x kr ,y kr ,z kr Bilateral supraorbital margin points S l '(x sl ,y sl ,z sl ), S r '(x sr ,y sr ,z sr ), bilateral infraorbital margin point B l '(x bl ,y bl ,z bl B r '(x br ,y br ,z br ) and bilateral lateral orbital margin points G l '(x gl ,y gl ,z gl ), G r '(x gr ,y gr ,z gr Characteristic points with clear edges, easy location, and distinct bony landmarks are selected. The distance d from the projection of each anatomical landmark onto the reconstructed postoperative skull stability reference plane MTM' normal direction after bilateral spatial repositioning is calculated. kl '、d kr '、d sl '、d sr '、d bl '、d br '、d gl '、d gr ', where d kl 'For point Kl The distance projected onto the plane in the normal direction of the postoperative skull stabilization reference plane (MTM) is used; the meaning of other distances is deduced similarly. Relevant parameters are recorded, and the difference between the postoperative corneal apex projection distance on each side and the average projection distances of the ipsilateral superior, inferior, and lateral orbital margins is calculated as the postoperative ocular exotropia measurement values ​​for the left and right sides.

[0059] The left eye protrusion Q was determined postoperatively. l ': D l '={d sl ',d bl ',d gl '},

[0060] Postoperative right eye protrusion Q r ': D r '={d sr ',d br ',d gr '},

[0061] Where n is the number of feature points on each side that are clearly defined, easy to locate, and have clear bony landmarks. In this embodiment, n = 3.

[0062] S300, Calculation of changes in eye extrusion: Calculate the difference in eye extrusion between the left and right sides before and after surgery, and then obtain the changes in eye extrusion between the left and right sides.

[0063] Specifically, the difference in eye exotropia before and after surgery on the left and right sides is calculated as the actual change in eye exotropia of the left eye and the actual change in eye exotropia of the right eye, which is used to achieve an objective and quantitative assessment of the efficacy of eye exotropia improvement under the scenario of changes in the spatial position of the periorbital bones before and after surgery.

[0064] The degree of improvement in left eye protrusion: ΔE l =Q l -Q l ',

[0065] The degree of improvement in right eye protrusion: ΔE r =Q r -Q r '.

[0066] As described above, in the three-dimensional ocular exotropia measurement method based on the skull stability reference plane of the present invention, a Frankfort plane is constructed in the preoperative three-dimensional CT image of the skull, symmetrical stable anatomical landmarks on both sides of the skull are marked, and a preoperative skull stability reference plane MTM perpendicular to the Frankfort plane is established based on the line connecting them. The preoperative bony landmark T on the top of the skull is selected for postoperative spatial matching. Furthermore, the present invention marks the corneal apex and bony orbital rim point respectively before surgery, and calculates the vertical distance from them to the preoperative skull stability reference plane MTM to obtain the preoperative ocular exotropia on the left and right sides. In the postoperative phase, the postoperative 3D CT images of the skull were rigidly registered to the coordinate system of the preoperative 3D CT images. The postoperative skull stable reference plane MTM' was reconstructed using the postoperative bony landmark T' (with the same anatomical position as the preoperative skull landmark T) and symmetrical stable anatomical landmarks on both sides of the skull (with the same anatomical position as preoperatively). The corneal apex and bony orbital rim were recalibrated, and their vertical distances to the MTM' plane were calculated to obtain the postoperative exophthalmos. Finally, the preoperative and postoperative differences were compared to objectively assess the degree of protrusion or regression of the eyeball. This method avoids the influence of changes in the spatial position of bony structures on the measurement, providing a unified and stable 3D reference benchmark. It is particularly suitable for preoperative and postoperative quantitative analysis and efficacy evaluation in cases of orbital morphological abnormalities such as orbital trauma and syndromic craniosynostosis (and is also applicable in other scenarios).

[0067] Furthermore, as described above, the method of the present invention can not only measure the degree of exophthalmos over a specific time period, but also measure the changes in the degree of exophthalmos before and after orbital bone movement surgery after CT bone registration. By registering the three-dimensional images of the skull before and after surgery, the cranial bone tissues overlap before and after surgery, so that the measurement reference plane remains unchanged before and after surgery. Even if the orbital bone is displaced, the change in the degree of exophthalmos can still be calculated and measured through a stable measurement reference plane. This method is highly innovative.

[0068] Based on the same inventive concept, the present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the aforementioned method for measuring three-dimensional eye protrusion based on a stable skull reference plane.

[0069] Based on the same inventive concept, the present invention also provides an electronic device, which includes a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, it implements the aforementioned three-dimensional eye protrusion measurement method based on a skull stability reference plane.

[0070] In practical applications, the aforementioned three-dimensional ocular protrusion measurement method based on a skull stability reference plane can be implemented using a processing system. For example, in one embodiment, the processing system includes an image acquisition module, an image processing module, a calculation module, and an output module. The image acquisition module acquires preoperative and postoperative three-dimensional CT images of the skull. The image processing module performs annotation, registration, and three-dimensional reconstruction on the image data, and constructs the Frankfort plane, the preoperative skull stability reference plane MTM, and the postoperative skull stability reference plane MTM'. The calculation module calculates the ocular protrusion measurement value and its change. The output module outputs the ocular protrusion measurement results and their changes.

[0071] In summary, the present invention provides a three-dimensional ocular protrusion measurement method, computer-readable storage medium, and electronic device based on a stable skull reference plane. This method preoperatively defines a preoperative stable skull reference plane (MTM) and a preoperative bony landmark T on the cranial vault. Postoperatively, through rigid registration, the symmetrical stable anatomical landmarks on both sides of the skull and the postoperative bony landmark T' on the cranial vault are aligned with the same preoperative anatomical location. This ensures that the postoperative stable skull reference plane MTM' coincides with the preoperative stable skull reference plane MTM, thereby maintaining consistency between the preoperative and postoperative measurement reference planes and guaranteeing the consistency of the measurement benchmark, thus ensuring the stability and reliability of the data. This method is particularly suitable for scenarios where the periorbital bone structure is unstable or its position changes preoperatively or postoperatively (such as orbital trauma, craniofacial osteotomy, etc.).

[0072] Furthermore, in calculating proptosis in this invention, the bilateral corneal apexes and multiple bony orbital rim points are calibrated, and their vertical distances relative to the preoperative cranial stability reference plane (MTM) or postoperative cranial stability reference plane (MTM') are measured to calculate the preoperative / postoperative proptosis. This method can accurately quantify proptosis in three-dimensional space, truly reflect the degree of protrusion relative to the orbital rim, and has strong clinical interpretability.

[0073] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0074] In the description of this invention, it should be understood that the terms "center," "height," "thickness," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0075] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0076] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0077] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

[0078] 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 three-dimensional eye protrusion measurement method based on a stable skull reference plane, characterized in that, Include: Preoperative ocular exotropia measurement: Based on the preoperative three-dimensional CT images of the subject's skull, a Frankfort plane was constructed; symmetrical stable anatomical landmarks on both sides of the skull were marked, and a preoperative skull stability reference plane MTM perpendicular to the Frankfort plane was established based on the line connecting the symmetrical stable anatomical landmarks on both sides of the skull. The intersection of this plane with the parietal bone was determined, and this intersection was used as the preoperative bony landmark T of the parietal bone; the preoperative ocular exotropia on the left and right sides was calculated. Postoperative exophthalmos measurement: Rigid body registration was performed between the postoperative 3D CT images of the skull and the preoperative 3D CT images of the skull; the position of the preoperative cranial bony landmark T in the registered postoperative 3D CT images of the skull was determined; combined with the stable anatomical landmarks on both sides of the skull that are the same as those before and after surgery, the postoperative skull stability reference plane MTM' consistent with the preoperative space was reconstructed; the exophthalmos was calculated on the left and right sides after surgery using the same method as before surgery. Calculation of changes in eye extrusion: Calculate the difference in eye extrusion between the left and right sides before and after surgery to obtain the changes in eye extrusion between the left and right sides.

2. The three-dimensional eye protrusion measurement method based on a stable skull reference plane as described in claim 1, characterized in that, In the preoperative ocular protrusion measurement, when acquiring the preoperative three-dimensional CT image data of the subject's skull, the scan needs to cover the entire orbital region, temporal bone region, and cranial vertex region.

3. The three-dimensional eye protrusion measurement method based on a stable skull reference plane as described in claim 1, characterized in that, In the preoperative ocular protrusion measurement, the construction of the preoperative cranial stability reference plane (MTM) includes: Based on the preoperative three-dimensional CT images of the subject's skull, the supraorbital points on both sides and any one of the infraorbital margins were marked. The Frankfort plane was constructed using these three points, which served as the horizontal reference plane for the middle of the skull. A line was established between symmetrical stable anatomical landmarks on both sides of the skull, and a three-dimensional coordinate system was established with the midpoint of the line as the origin. Based on the line connecting the symmetrical stable anatomical landmarks on both sides of the skull, a preoperative skull stability reference plane MTM perpendicular to the Frankfort plane was established. The intersection of the preoperative skull stability reference plane MTM and the parietal bone was determined, and this intersection was used as the preoperative cranial parietal bony landmark T. The preoperative cranial parietal bony landmark T served as the landmark of the postoperative skull stability reference plane MTM'.

4. The three-dimensional eye protrusion measurement method based on a stable skull reference plane as described in claim 1, characterized in that, In the postoperative ocular protrusion measurement, when acquiring the postoperative three-dimensional CT image data of the subject's skull, the scan needs to cover the entire orbital region, temporal bone region, and cranial vertex region.

5. The three-dimensional eye protrusion measurement method based on a stable skull reference plane as described in claim 1, characterized in that, In the postoperative ocular protrusion measurement, the reconstructed postoperative cranial stability reference plane MTM' includes: In the postoperative 3D CT images of the skull, symmetrical stable anatomical landmarks on both sides of the skull, identical to those before surgery, were marked. Rigid body registration was performed on the postoperative 3D CT images of the skull based on the skull base, auricular region, and adjacent skull structures to align them spatially with the preoperative 3D CT images of the skull. In the registered postoperative 3D CT images of the skull, the corresponding postoperative cranial bony landmark T' was accurately restored in the postoperative 3D CT images based on the positional information of the preoperative cranial bony landmark T recorded before surgery. Based on the postoperative cranial bony landmark T' and the symmetrical stable anatomical landmarks on both sides of the skull, a postoperative skull stability reference plane MTM' consistent with the preoperative space was reconstructed.

6. The three-dimensional eye protrusion measurement method based on a stable skull reference plane as described in claim 1, characterized in that, Calculating the protrusion of the left and right eyes includes: The left and right corneal apexes and multiple bony orbital rim points were marked, and their vertical distances relative to the preoperative skull stability reference plane MTM or the postoperative skull stability reference plane MTM' were measured to calculate the left and right ocular protrusion before or after surgery.

7. The three-dimensional eye protrusion measurement method based on a stable skull reference plane as described in claim 1, characterized in that, The calculation of preoperative ocular protrusion measurement values ​​includes: In the preoperative three-dimensional CT images of the skull, mark the bilateral corneal apex, bilateral supraorbital margin, bilateral infraorbital margin, and bilateral lateral orbital margin. Calculate the distance of each of the above bilateral anatomical landmarks projected in space along the normal direction of the preoperative skull stability reference plane (MTM) to the preoperative skull stability reference plane (MTM). Record the relevant parameters and calculate the difference between the preoperative corneal apex projection distance of each side and the average projection distance of the ipsilateral supraorbital, infraorbital, and lateral orbital margins. Use this as the preoperative ocular protrusion measurement value for the left and right sides. The calculation of postoperative ocular protrusion measurement values ​​includes: In the postoperative three-dimensional CT images of the skull, the same bilateral anatomical landmarks as those in the preoperative three-dimensional CT images of the skull were marked. The distance of each anatomical landmark projected onto the reconstructed postoperative skull stability reference plane MTM' after the change in bilateral spatial position was calculated. The relevant parameters were recorded and the difference between the postoperative corneal vertex projection distance of each side and the mean projection distance of the ipsilateral superior, inferior and lateral orbital margins was calculated as the postoperative ocular exotropia measurement values ​​for the left and right sides.

8. The three-dimensional eye protrusion measurement method based on a stable skull reference plane as described in claim 1, characterized in that, The stable anatomical landmarks symmetrical on both sides of the skull include at least one of the following: bilateral mastoid points, bilateral soft foramina, bilateral spinous foramina, and bilateral supraorbital points.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the three-dimensional eye protrusion measurement method based on the skull stability reference plane as described in any one of claims 1 to 8.

10. An electronic device comprising a processor and a memory, wherein the memory stores a computer program, characterized in that, When the computer program is executed by the processor, it implements the three-dimensional eye protrusion measurement method based on the skull stability reference plane as described in any one of claims 1 to 8.

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