Intraoperative image matching method, device and system based on C-arm machine

Abstract

The present invention relates to an intraoperative image matching method and system based on a C-arm machine. The method comprises: obtaining a preoperative three-dimensional image of a detection object; photographing the detection object at a first position by a C-arm machine to obtain a first X-ray image; photographing the detection object at a second position by a C-arm machine to obtain a second X-ray image; rotating and / or translating the preoperative three-dimensional image to obtain a spatially transformed three-dimensional image, each spatially transformed three-dimensional image having corresponding transformation parameters; executing on part or all of the spatially transformed three-dimensional images: projecting the spatially transformed three-dimensional image as a first projection image, calculating a first similarity between the first projection image and the first X-ray image; projecting the spatially transformed three-dimensional image as a second projection image, calculating a second similarity between the second projection image and the second X-ray image; using the transformation parameters of the spatially transformed three-dimensional image that meet the optimization conditions as the optimal transformation parameters; and aligning the preoperative three-dimensional image to the intraoperative imaging space according to the optimal transformation parameters.

Description

Technical Field

[0001] The present invention mainly relates to the field of surgical navigation, and in particular to a C-arm-based intraoperative image matching method, device, system and computer-readable medium. Background Art

[0002] Surgical navigation technology is also known as Image Guided Surgery. It combines computer image processing technology with medical imaging technology to perform organ or tissue segmentation on patient images before surgery, develop surgical plans, and simulate surgery. During surgery, the patient space is aligned with the preoperative image space, and the surgical instruments, patient position, and preoperative images are converted into a unified spatial coordinate system. This allows the surgeon to accurately reach the lesion location at the fastest speed and complete the surgical treatment.

[0003] The existing surgical planning schemes usually involve doctors manually locating the lesion area based on the three-dimensional images of the patient obtained before the operation, and then formulating the surgical plan accordingly. During the operation, the surgical position is located through trauma, the doctor's touch, or the patient's external artificial marking points, multiple X-ray images, etc. These surgical plans do not fully use the coordinate position relationship in the preoperative image, and often lack the matching of the real scene before and during the operation. Trauma or multiple X-ray images will cause a certain degree of damage to the patient, and have the disadvantages of complex operation and harsh surgical environment. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a C-arm-based intraoperative image matching method, device, system and computer-readable medium for quickly and accurately aligning preoperative three-dimensional images to intraoperative imaging space.

[0005] The technical solution adopted by the present invention to solve the above technical problems is an intraoperative image matching method based on a C-arm machine, comprising: obtaining a preoperative three-dimensional image of a detected object; adjusting the position of an X-ray light source of the C-arm machine to a first position, photographing the detected object by the C-arm machine to obtain a first X-ray image; adjusting the position of the X-ray light source to a second position, photographing the detected object by the C-arm machine to obtain a second X-ray image, wherein an angle is formed between the first position and the second position; rotating and / or or translation to obtain a plurality of spatially transformed three-dimensional images, each of which has corresponding transformation parameters; performing the following steps ac on some or all of the spatially transformed three-dimensional images: step a: projecting the spatially transformed three-dimensional image as a first projection image according to the first position, and calculating a first similarity between the first projection image and the first X-ray image; step b: projecting the spatially transformed three-dimensional image as a second projection image according to the second position, and calculating a second similarity between the second projection image and the second X-ray image; step c: taking the transformation parameters of the spatially transformed three-dimensional image that meet the optimization conditions as the optimal transformation parameters, and the optimization conditions are set according to the first similarity and the second similarity; aligning the preoperative three-dimensional image to the intraoperative imaging space according to the optimal transformation parameters.

[0006] In one embodiment of the present invention, the angle ranges from 45 degrees to 135 degrees.

[0007] In one embodiment of the present invention, the transformation parameters include: one or any combination of: a rotation angle around the X-axis, a rotation angle around the Y-axis, a rotation angle around the Z-axis, a translation distance along the X-axis, a translation distance along the Y-axis, and a translation distance along the Z-axis, wherein the X-axis, the Y-axis, and the Z-axis are the spatial coordinate axes of the preoperative three-dimensional image.

[0008] In one embodiment of the present invention, the first X-ray image is an anteroposterior image of the detected object, and the second X-ray image is a lateral image of the detected object.

[0009] In one embodiment of the present invention, the pre-operative three-dimensional image is a segmented image, and the detection object is a region of interest of the surgical object.

[0010] In one embodiment of the present invention, the optimization condition in step c includes: the sum or weighted sum of the first similarity and the second similarity is maximum.

[0011] In one embodiment of the present invention, it also includes: obtaining the first position and / or the second position according to the following steps: obtaining a first image by shooting an imaging space with the C-arm machine, the imaging space includes a plurality of spatial markers, each of the spatial markers has a first spatial coordinate, and the plurality of spatial markers correspond to a plurality of marker images in the first image, each of the marker images has a second spatial coordinate, wherein the first image is located in a first imaging plane in the imaging space; obtaining the distance between the X-ray source of the C-arm machine and the first imaging plane; and calculating the X-ray source position of the C-arm machine according to the first spatial coordinate, the second spatial coordinate and the distance.

[0012] In one embodiment of the present invention, the first imaging plane includes a projection imaging plane of the C-arm machine.

[0013] In an embodiment of the present invention, the plurality of spatial markers are arranged on a spatial marker plate, and the spatial marker plate is arranged in the imaging space.

[0014] In one embodiment of the present invention, the imaging space also includes a detection object, the space marking plate is adjacent to and not in contact with the detection object, and the first image also includes an image of the detection object.

[0015] In one embodiment of the present invention, it also includes: obtaining the first spatial coordinates by the following method: connecting the spatial marker plate to a tracing device, wherein the tracing device and the spatial marker plate have a positional relationship; and obtaining the first spatial coordinates according to the spatial position of the tracing device and the positional relationship.

[0016] In one embodiment of the present invention, the step of calculating the X-ray source position of the C-arm machine according to the first spatial coordinates, the second spatial coordinates and the distance includes: one-to-one correspondence between multiple first spatial coordinates and multiple second spatial coordinates; and in the imaging space, respectively connecting multiple first spatial coordinates and corresponding multiple second spatial coordinates to form multiple virtual straight lines, the multiple virtual straight lines have an intersection, and calculating the spatial coordinates of the intersection as the X-ray source position.

[0017] In one embodiment of the present invention, the step of making a one-to-one correspondence between a plurality of the first spatial coordinates and a plurality of the second spatial coordinates includes: determining an initial marker among the plurality of spatial markers, taking the initial marker as a reference, and numbering the remaining spatial markers according to the first positional relationship between the remaining spatial markers and the reference, so that each of the spatial markers has a first number; determining an initial marker image corresponding to the initial marker in the first image, calculating the second positional relationship between the initial marker image and the remaining marker images, and numbering the remaining marker images according to the second positional relationship, so that each of the marker images has a second number, and the second number corresponds one-to-one to the first number.

[0018] In one embodiment of the present invention, the spatial coordinates of the intersection point are calculated using the following set of equations:

[0019]

[0020] Ax i +By i +Cz i +d=0,

[0021]

[0022]

[0023] Among them, (u i ,v i ) represents the second two-dimensional spatial coordinate of the marker image, r 11 -r 32 is the unknown number to be solved in the transformation matrix, (x i ,y i ,z i ) is the second spatial coordinate of the three-dimensional space after transformation, Ax i +By i + Cz i +D=0 represents the plane equation of the first imaging plane, (x j ,y j ,z j ) represents the first spatial coordinate, (x0, y0, z0) represents the spatial coordinate of the intersection, d represents the distance, i, j = 1: m, m is the total number of the spatial markers; multiple first spatial coordinates (x j ,y j ,z j ), a plurality of the two-dimensional second space coordinates (u i ,v i) and the distance d are substituted into the equation group to obtain the spatial coordinates (x0, y0, z0) of the intersection point.

[0024] To solve the above technical problems, the present invention further proposes an intraoperative image matching device based on a C-arm machine, comprising: a memory for storing instructions executable by a processor; and a processor for executing the instructions to implement the above method.

[0025] To solve the above technical problem, the present invention further provides a computer-readable medium storing computer program codes, wherein the computer program codes implement the above method when executed by a processor.

[0026] In order to solve the above technical problems, the present invention also proposes an intraoperative image matching system based on a C-arm machine, comprising: a 3D image acquisition unit, used to acquire a preoperative 3D image of a detected object; a controller, configured to: adjust the X-ray source position of the C-arm machine to a first position, and obtain a first X-ray image by photographing the detected object through the C-arm machine; adjust the X-ray source position to a second position, and obtain a second X-ray image by photographing the detected object through the C-arm machine, wherein an angle is formed between the first position and the second position; rotate and / or translate the preoperative 3D image to obtain a plurality of spatially transformed 3D images, each of which has corresponding transformation parameters; and perform partial or complete transformation on the three-dimensional image. The spatially transformed three-dimensional image executes the following steps ac: step a: projecting the spatially transformed three-dimensional image as a first projection image according to the first position, and calculating a first similarity between the first projection image and the first X-ray image; step b: projecting the spatially transformed three-dimensional image as a second projection image according to the second position, and calculating a second similarity between the second projection image and the second X-ray image; step c: taking the transformation parameters of the spatially transformed three-dimensional image that meet the optimization conditions as optimal transformation parameters, and the optimization conditions are set according to the first similarity and the second similarity; and aligning the preoperative three-dimensional image to the intraoperative imaging space according to the optimal transformation parameters.

[0027] The present invention adjusts the position of the C-arm during surgery, obtains two-dimensional X-ray images at two different positions, performs spatial transformation on the preoperative three-dimensional image, projects the preoperative three-dimensional image at the two different positions into two-dimensional projection images, compares the similarity between the projection images at the two different positions and the two-dimensional X-ray images, and can quickly obtain optimal transformation parameters that meet the optimization conditions, so that the preoperative three-dimensional image can be quickly aligned to the intraoperative imaging space, which is conducive to realizing accurate navigation of the surgery. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein:

[0029] Figure 1 is an exemplary flow chart of an intraoperative image matching method based on a C-arm machine according to an embodiment of the present invention;

[0030] Figure 2 1 is a schematic diagram of the principle of an intraoperative image matching method based on a C-arm machine according to an embodiment of the present invention;

[0031] Figure 3 is a flowchart of an exemplary method for obtaining a first position and / or a second position in an intraoperative image matching method according to an embodiment of the present invention;

[0032] Figure 4 is a schematic diagram of an application scenario of the step of obtaining a first position and / or a second position in the intraoperative image matching method according to an embodiment of the present invention;

[0033] Figure 5 is a schematic diagram of the three-dimensional structure of a space marker plate in an intraoperative image matching method according to an embodiment of the present invention;

[0034] Figure 6 is a schematic diagram of a first image in an intraoperative image matching method according to an embodiment of the present invention;

[0035] Figure 7 It is a schematic diagram of the principle of obtaining the first position and / or the second position in the intraoperative image matching method according to an embodiment of the present invention;

[0036] Figure 8 is a block diagram of an intraoperative image matching system based on a C-arm machine according to an embodiment of the present invention;

[0037] Fig. 9 It is a system block diagram of an intraoperative image matching device based on a C-arm machine according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0039] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0040] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "a kind" and / or "the" do not refer to the singular, but also include the plural. Generally speaking, the terms "comprise" and "include" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list, and the method or device may also include other steps or elements.

[0041] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0042] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.

[0043] Flowcharts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, various steps may be processed in reverse order or simultaneously. At the same time, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0044] The C-arm-based intraoperative image matching method of the present invention quickly matches the preoperative three-dimensional image with the intraoperative two-dimensional image, aligns the preoperative three-dimensional image to the intraoperative imaging space, and can transform the coordinates of the surgical path, points, etc. planned in the preoperative three-dimensional image to the intraoperative imaging space, providing accurate navigation for the surgery.

[0045] Figure 1 This is an exemplary flow chart of an intraoperative image matching method based on a C-arm machine according to an embodiment of the present invention.

[0046] refer to Figure 1 As shown, the intraoperative image matching method of this embodiment includes the following steps:

[0047] Step S110: acquiring a preoperative three-dimensional image of the detection object;

[0048] Step S120: adjusting the X-ray source position of the C-arm machine to a first position, and photographing the detection object by the C-arm machine to obtain a first X-ray image;

[0049] Step S130: adjusting the position of the X-ray light source to a second position, photographing the detection object with a C-arm machine to obtain a second X-ray image, wherein an angle is formed between the first position and the second position;

[0050] Step S140: rotating and / or translating the preoperative three-dimensional image to obtain a plurality of spatially transformed three-dimensional images, each of which has corresponding transformation parameters;

[0051] Step S150: Perform the following steps ac on part or all of the spatially transformed 3D image:

[0052] Step a: projecting the spatially transformed three-dimensional image into a first projection image according to the first position, and calculating a first similarity between the first projection image and the first X-ray image;

[0053] Step b: projecting the spatially transformed three-dimensional image into a second projection image according to the second position, and calculating a second similarity between the second projection image and the second X-ray image;

[0054] Step c: taking the transformation parameters of the spatially transformed three-dimensional image that meet the optimization condition as the optimal transformation parameters, wherein the optimization condition is set according to the first similarity and the second similarity;

[0055] Step S160: aligning the preoperative three-dimensional image to the intraoperative imaging space according to the optimal transformation parameters.

[0056] The following is combined with Figure 2 The above steps S110 - S160 are described.

[0057] In step S110, the detection object may be any object such as a patient, a test phantom, an animal, etc. The preoperative three-dimensional image may be acquired by any device, such as a CT device, and the preoperative three-dimensional image is a three-dimensional CT image.

[0058] In some embodiments, after obtaining the preoperative 3D image, a region of interest may be manually selected and used as the preoperative 3D image to be used in subsequent steps, thereby reducing the size of the image to be processed and increasing the processing speed.

[0059] In some embodiments, the preoperative three-dimensional image is a segmented image, and the detection object is the region of interest of the surgical object. For example, for spinal surgery, the three-dimensional image is the human vertebrae related to the surgical site after image segmentation. The region of interest of the surgical object refers to the area where the surgical operation needs to be performed, such as lumbar vertebrae L3, L4, L5, etc.

[0060] The present invention does not limit the method of image segmentation, and can be performed using a VNet neural network or other image processing methods in the art. After image segmentation, various organs and parts can be segmented and named from the preoperative three-dimensional image. Then, the lesion, lesion location or area can be marked in the preoperative three-dimensional image using image processing, manual marking by a doctor, etc. The region of interest can be an area including the lesion. According to these embodiments, the images in the intraoperative matching method of the present invention are all for the region of interest. Multiple regions of interest can be included, and the regions of interest are matched in real time in sequence during the operation according to the progress of the operation.

[0061] According to the intraoperative matching method of the present invention, the current region of interest of the surgical object can be matched. Since the volume of the region of interest is small, the amount of calculation can be reduced and the calculation speed can be improved. During the operation, compared with the preoperative three-dimensional image, the difference in the patient's posture may cause the X-ray image of the same part to have a large difference with the preoperative three-dimensional image. For example, bending over causes the state of the lumbar spine to change. Therefore, using the region of interest to reduce the image object to be matched can also improve the accuracy of matching.

[0062] Before surgery, surgical path planning can be performed manually or automatically, and the starting point, path, and end point of the surgery can be planned in the preoperative three-dimensional image. The coordinates of these points and paths correspond to the coordinates of the preoperative three-dimensional image. In order to apply the planned path and point coordinates during surgery, the preoperative three-dimensional image needs to be aligned to the intraoperative imaging space. During surgery, a C-arm machine is used to capture an intraoperative two-dimensional image of the detected object, and the preoperative three-dimensional image is aligned to the intraoperative imaging space, so that the coordinates in the preoperative three-dimensional image correspond to the coordinates of the intraoperative two-dimensional image, which is conducive to providing accurate navigation for surgery.

[0063] Figure 2 FIG. 1 is a schematic diagram of the principle of an intraoperative image matching method based on a C-arm machine according to an embodiment of the present invention. Figure 2As shown, in step S120, the X-ray source 210 of the C-arm machine is adjusted to the first position P1, and accordingly, the detector 220 of the C-arm machine is located opposite to the X-ray source 210, and a first X-ray image of the detection object 230 is obtained in this position. Figure 2 As shown, in step S130, the X-ray source 210 of the C-arm machine is adjusted to the second position P2, and accordingly, the detector 220 of the C-arm machine is located opposite to the X-ray source 210, and a second X-ray image of the detection object 230 is obtained in this position.

[0064] In some embodiments, the angle between the first position P1 and the second position P2 ranges from 45 degrees to 135 degrees. Figure 2 In the illustrated embodiment, the angle between the first position P1 and the second position P2 is 90 degrees, wherein the first X-ray image is an anteroposterior image of the detected object 230 , and the second X-ray image is a lateral image of the detected object 230 .

[0065] It should be noted that step S120 and step S130 do not limit the number of the first position and the second position. According to step S120 and step S130, the intraoperative image matching method of the present invention can at least obtain two X-ray images with the X-ray source located at two different positions. In the subsequent step of projecting the spatially transformed three-dimensional image, the number of the obtained projection images can be equal to the number of X-ray images, or two X-ray source positions can be selected from multiple X-ray source positions to obtain the projection images.

[0066] In some embodiments, the transformation parameters in step S140 include: one or any combination of: rotation angle around the X axis, rotation angle around the Y axis, rotation angle around the Z axis, translation distance along the X axis, translation distance along the Y axis, and translation distance along the Z axis, wherein the X axis, the Y axis, and the Z axis are the spatial coordinate axes of the preoperative three-dimensional image. In some embodiments, the transformation parameters include all six parameters.

[0067] In step S140, the preoperative three-dimensional image is rotated and / or translated to obtain a plurality of spatially transformed three-dimensional images. Assume that the transformation parameter is an array paras[6] containing 6 variables. After a spatial transformation, at least one of the 6 variables changes.

[0068] In some embodiments, steps S140 and S150 may be performed in an iterative manner, as follows:

[0069] Step S171: Initialize transformation parameters, for example, set paras[6] = [0, 0, 0, 0, 0], or set paras[6] equal to a preset initial value based on experience.

[0070] Step S172: Rotate and / or translate the preoperative 3D image to obtain a spatially transformed 3D image, where the transformation parameters are paras i , i = 1: N, N is the total number of all spatially transformed three-dimensional images. i There is no restriction on the specific variation parameters.

[0071] Step S173: Execute steps a, b, and c in step S150.

[0072] In step a, the step of projecting the spatially transformed three-dimensional image into a first projection image according to the first position P1 includes: projecting using a digitally reconstructed radiograph (DRR) method. It can be understood that the DRR method can project a three-dimensional image into a two-dimensional image according to the current position of the X-ray source, and when the first position P1 is known, the first projection image can be obtained according to the DRR method.

[0073] The present invention does not limit the method for calculating the first similarity between the first projection image and the first X-ray image in step a, which may be, for example, a method based on grayscale mutual information, cross-correlation, or a method based on contours, feature points, etc.

[0074] Similarly, step b may adopt the same method as step a, when the second position P2 is known, obtain the second projection image according to the DRR method, and calculate the second similarity using the same method as step a.

[0075] It can be understood that the first projection image and the second projection image are both two-dimensional images. According to steps a and b, the three-dimensional spatial image is reduced to a two-dimensional image.

[0076] In some embodiments, in step c, the optimization condition includes: the sum or weighted sum of the first similarity and the second similarity is maximized. When the sum of the first similarity S1 and the second similarity S2 is maximized, the result of S1+S2 is maximized.

[0077] The weighted sum of the first similarity and the second similarity can be calculated using the following formula:

[0078] WSum=w1*S1+w2*S2;

[0079] w1+w2=1.

[0080] Wherein, WSum represents a weighted sum, S1 represents a first similarity, S2 represents a second similarity, w1 is a first weight assigned to S1, and w2 is a second weight assigned to S2.

[0081] Repeat the above steps S172 and S173, each time setting i=i+1 to update the spatially transformed three-dimensional image, so that part or all of the spatially transformed three-dimensional image executes steps a, b, and c in step S150, and the transformation parameters of the spatially transformed three-dimensional image with the largest sum or weighted sum of the first similarity and the second similarity are taken as the optimal transformation parameters.

[0082] Steps S172-S173 may be iterated and optimized using an iterative method in the art, including but not limited to the Powell method, the gradient descent method, the Newton method, etc. In these embodiments, the first loss function Loss1=1-first similarity is calculated according to the first similarity, the second loss function Loss2=1-second similarity is calculated according to the second similarity, and the total loss function Loss=Loss1+Loss2. Then the optimization condition in step c is: the total loss function Loss is minimized.

[0083] After step 150, the optimal transformation parameters and their corresponding spatial transformation 3D images are obtained. It can be understood that the spatial transformation 3D image has the best match with the 2D image in the intraoperative imaging space. In step S160, the preoperative 3D image is aligned to the intraoperative imaging space according to the optimal transformation parameters.

[0084] According to the intraoperative image matching method of steps S110-S160, the optimal transformation parameters can be quickly obtained, so that the preoperative three-dimensional image can be quickly aligned to the intraoperative imaging space, which is conducive to achieving accurate navigation of the surgery.

[0085] In some embodiments, the first position and the second position in steps S120 and S130 may be obtained in real time by calculation.

[0086] Figure 3 FIG. 1 is a flowchart of an exemplary method for obtaining a first position and / or a second position in an intraoperative image matching method according to an embodiment of the present invention. Figure 3 As shown, the method for obtaining the first position and / or the second position comprises the following steps:

[0087] Step S310: obtaining a first image by photographing an imaging space through a C-arm machine, wherein the imaging space includes a plurality of spatial markers, each of which has a first spatial coordinate, and the plurality of spatial markers correspond to a plurality of marker images in the first image, each of which has a second spatial coordinate, wherein the first image is located in a first imaging plane in the imaging space;

[0088] Step S320: obtaining the distance between the X-ray source of the C-arm machine and the first imaging plane; and

[0089] Step S330: Calculate the X-ray source position of the C-arm machine according to the first spatial coordinate, the second spatial coordinate and the distance.

[0090] The following combination Figure 4-7 The above steps S310-S330 are explained.

[0091] Figure 4 1 is a schematic diagram of an application scenario of the step of obtaining the first position and / or the second position in the intraoperative image matching method according to an embodiment of the present invention. Figure 4 As shown, an X-ray source 420 and a detector 430 of a C-arm machine are shown, and the two are respectively located at two ends of a C-arm 410. During surgery, in order to take a picture of a patient, the C-arm 410 is moved so that the patient is located in an imaging space between the X-ray source 420 and the detector 430. Figure 4 As shown, the imaging space can be defined by a dotted line between the X-ray source 420 and the detector 430 , and the C-arm machine can image the detection object 440 placed in the imaging space.

[0092] Figure 4 The figure is for illustration only, and the detection object 440 can be any object such as a patient, a test model, an animal, etc.

[0093] In step S310, the imaging space refers to the three-dimensional space between the X-ray source 420 and the detector 430. A plurality of spatial markers are set in the imaging space, and these spatial markers have first spatial coordinates. In this embodiment, the spatial coordinates are represented by three-dimensional coordinates. The present invention does not limit how to set the plurality of spatial markers. It can be understood that the C-arm machine can image the spatial markers, and therefore, the spatial markers are made of imageable materials.

[0094] refer to Figure 4 As shown, in some embodiments, a plurality of spatial markers are disposed on a spatial marker plate 450 , and the spatial marker plate 450 is disposed in the imaging space.

[0095] Figure 5 FIG. 1 is a schematic diagram of the three-dimensional structure of a space marker plate in an intraoperative image matching method according to an embodiment of the present invention. Figure 5 As shown, in this embodiment, the space marker 510 is spherical and is disposed in a recess 520 in the space marker plate 450 .

[0096] In step S310, the spatial marker has a certain shape and size, and the first spatial coordinate of the spatial marker may refer to the spatial coordinate of a specified position point on the spatial marker. Figure 5As shown, each sphere used as a spatial marker has the same size and shape, and the spatial coordinates of the center of the sphere or a point on the surface of the sphere are used as the first spatial coordinates of the spatial marker.

[0097] like Figure 4 As shown, it is assumed that the detection object 440 is a patient, and the space marker plate 450 is arranged adjacent to the patient and the two are not in direct contact with each other. Figure 4 In the embodiment, the space marker plate 450 is located above the detection object 440, that is, the space marker plate 450 is closer to the X-ray source 420. In other embodiments, the space marker plate 450 may be located below the detection object 440, that is, the space marker plate 450 is closer to the detector 430.

[0098] like Figure 4 As shown, the spatial marker plate 450 may not be parallel to the receiving surface of the detector 430 .

[0099] In some embodiments, the first space coordinates are obtained by the following method:

[0100] Step S311: connecting the space marker plate to the tracing device, wherein the tracing device and the space marker plate have a positional relationship; and

[0101] Step S312: Obtain a first spatial coordinate according to the spatial position of the tracing device and the positional relationship.

[0102] like Figure 4 As shown, the tracing device includes a connecting rod 460, and the space marking plate 450 is connected to the connecting rod 460. A plurality of tracing marks, such as tracer balls, are arranged on the connecting rod 460. The spatial positions of these tracer balls, that is, the spatial position of the tracing device, can be provided in real time by a positioning system matched with the tracer balls. The present invention does not limit how the positioning system obtains the spatial position of the tracer ball. In some embodiments, an optical method is used for positioning, and the positioning system is an optical positioning system. The positioning process is, for example: the tracer ball actively transmits or passively reflects so that the optical positioning system receives the active emission light or the passive reflection light, and the optical positioning system locates and tracks the tracer ball according to the received light.

[0103] In some embodiments, the tracer device is NDI (ndigital) Marker ball and NDI optical positioning system.

[0104] like Figure 4As shown, there is a fixed positional relationship between the spatial marker plate 450 and the connecting rod 460, and the positional relationship includes the relative positional relationship between each tracer ball on the connecting rod 460 and each spatial marker on the spatial marker plate 450. The first spatial coordinate of each spatial marker can be derived according to the spatial position and positional relationship of the tracer ball.

[0105] In this embodiment, the connecting rod 460 can be set at the bedside and does not come into contact with the patient during the operation.

[0106] Figure 6 FIG. 5 is a schematic diagram of a first image in an intraoperative image matching method according to an embodiment of the present invention. Figure 6 As shown, Figure 5 The plurality of spatial markers 510 in the first image 601 correspond to a plurality of marker images 610. It can be understood that the first image 601 is a two-dimensional plane image. When the spatial marker 510 is a sphere, the marker image 610 is a circle. Figure 4 The illustration is not intended to limit the actual size and shape of the first image 601. The first image 601 is captured by a C-arm machine, and its shape and size are set by the parameters of the C-arm machine itself. The second spatial coordinates of the marked image 610 can also be the spatial coordinates of any point in the marked image. For example, the spatial coordinates of the center of a circle or a point therein are specified as the second spatial coordinates of the marked image 610.

[0107] In some embodiments, multiple spatial markers 510 are spheres, and the center of each sphere is located in the same plane. The spatial coordinates of the center of each sphere are used as the first spatial coordinates of the spatial marker 510, and the center of each sphere projected into the marker image 610 in the first image 601 is used as the second spatial coordinates.

[0108] Figure 7 FIG. 1 is a schematic diagram showing the principle of obtaining the first position and / or the second position in the intraoperative image matching method according to an embodiment of the present invention. Figure 7 As shown, the first image 601 is located in the first imaging plane 710 in the imaging space. The first imaging plane 710 is a plane in the imaging space, and the marker image 610 located in the first image 601 has a second space coordinate in the imaging space.

[0109] In step S320, the distance between the X-ray source 420 and the first imaging plane 710 is obtained. The present invention does not limit how to obtain the distance, and those skilled in the art can obtain the distance by direct measurement or indirect deduction.

[0110] In some embodiments, the first imaging plane 710 includes a projection imaging plane of the C-arm machine. That is, the first imaging plane 710 and the projection imaging plane of the C-arm machine are the same plane. The distance d from the X-ray source 420 to the first imaging plane 710 is equal to the distance d' from the X-ray source 420 to the projection imaging plane, where the distance d' is an internal parameter of the C-arm machine. When obtaining a DICOM image as the first image 601, the distance d' can be simultaneously obtained from the additional information of the DICOM image, thereby obtaining the distance d in step S120.

[0111] In some embodiments, step S330 includes the following steps:

[0112] Step S331: Matching the plurality of first space coordinates with the plurality of second space coordinates one by one;

[0113] Step S332: In the imaging space, a plurality of first spatial coordinates and corresponding second spatial coordinates are respectively connected to form a plurality of virtual straight lines, the plurality of virtual straight lines have an intersection point, and the spatial coordinates of the intersection point are calculated as the position of the X-ray source.

[0114] According to the positioning method of the present invention, multiple marker images 610 and multiple spatial markers 510 have a one-to-one correspondence physically. However, after generating the first image 601, it is still necessary to determine the one-to-one correspondence between each marker image 610 and each spatial marker 510 for subsequent calculations.

[0115] In some embodiments, step S331 includes the following steps:

[0116] Step S3311: determining an initial marker among a plurality of spatial markers, taking the initial marker as a reference, and numbering the remaining spatial markers according to a first positional relationship between the remaining spatial markers and the reference, so that each spatial marker has a first number;

[0117] Step S3312: Determine the initial marking image corresponding to the initial marking object in the first image, calculate the second positional relationship between the initial marking image and the remaining marking images, and number the remaining marking images according to the second positional relationship so that each marking image has a second number, and the second number corresponds to the first number one by one.

[0118] Combine the following Figure 5-6 Steps S3311-S3312 are described. Figure 5As shown, it is assumed that there is a coordinate system O1X1Y1, with columns extending along the Y1 axis and rows extending along the X1 axis. In addition to having the characteristics of row and column arrangement, the multiple spatial markers 510 in the spatial marker plate 450 have different numbers of spatial markers 510 in each column, and the contours of the multiple spatial markers 510 are roughly right-angled trapezoids with four endpoints. In step S3311, one of the four endpoints is selected as the initial marker T00. In other embodiments, spatial markers at other endpoint positions can also be selected as initial markers. The remaining spatial markers have a unique first position relationship with the initial marker T00. For example, the first position relationship is distance and direction, and the distance and direction between each of the remaining spatial markers and the initial marker T00 are different, then each spatial marker can be determined according to the distance and direction. The direction here can be the vector direction of each spatial marker with the point O1 of the coordinate system O1X1Y1 as the origin, or it can be the direction of the line between each spatial marker and the initial marker T00.

[0119] Figure 5 Several first numbers are shown, including T10, T20, ... T60 located in the same column as the initial marker T00, T01, T02, T03 located in the same row as the initial marker T00, T33 located in the same column as T03, and T11 located in the same row as T10. Figure 5 As shown, each space marker is numbered according to the row and column rule, so that each space marker has a first number.

[0120] like Figure 6 As shown, assuming that the first image 601 has a coordinate system O2X2Y2, the multiple marker images 610 have row and column arrangement characteristics corresponding to the multiple spatial markers, wherein the direction of the row is not parallel to the extension direction of the horizontal axis X2, and the direction of the column is not parallel to the extension direction of the vertical axis Y2. Nevertheless, the relative position relationship of the multiple marker images 610 is consistent with the relative position relationship of the multiple spatial markers 510. An exemplary process for numbering each marker image is given below.

[0121] 1) Determine the initial marker image P00 corresponding to the initial marker T00. Figure 5 As shown, the initial mark image P00 is located in the upper left corner.

[0122] 2) Determine the two labeled images P01 and P10 that are closest to the initial labeled image P00 among the remaining labeled images, and calculate the vector differences between the two labeled images and the initial labeled image P00 as follows:

[0123] v1=P 01 (x1,y1)-P00 (x0,y0)

[0124] v2=P 10 (x2,y2)-P 00 (x0,y0)

[0125] Among them, the coordinates of the initial marked image P00 are P 00 (x0,y0), the coordinates of the labeled image P01 are P 01 (x1, y1), the coordinates of the marker image P10 are P 10 (x2,y2).

[0126] 3) The directions of the vector differences V1 and V2 are used as the new coordinate axis directions. According to the vector differences between other marker images and the initial marker image P00, the new coordinates of each marker image can be determined, thereby determining the arrangement order of each marker image.

[0127] 4) Number each marked image according to the arrangement order, so that each marked image has a second number, such as Figure 4 As shown in FIG. 1 , P10, P20, ... P60 are located in the same column as the initial labeled image P00, P01, P02, P03 are located in the same row as the initial labeled image P00, P33 is located in the same column as P03, and P11 is located in the same row as P10. The numbers in the second numbering correspond to the numbers in the first numbering.

[0128] Need to explain, Figure 5-6 The figure is not intended to limit the specific implementation of steps S331-S332, and those skilled in the art may adopt any method to obtain a one-to-one correspondence between a plurality of first space coordinates and a plurality of second space coordinates.

[0129] refer to Figure 7 As shown, in step S332, the virtual straight line is not a real straight line, but in the imaging space, the first spatial coordinates of each spatial marker 510 and the second spatial coordinates of the marker image 610 are mathematically connected to obtain a straight line expression of the virtual straight line in the imaging space. According to the imaging projection principle, multiple virtual straight lines between multiple marker images 610 and multiple spatial markers 510 should converge at the X-ray source position. Therefore, the X-ray source position can be obtained by calculating the intersection of multiple virtual straight lines.

[0130] In some embodiments, the spatial coordinates of the intersection point are calculated using the following set of equations:

[0131]

[0132] It includes four equations (1)-(4). In equation (1), (ui ,v i ) represents the two-dimensional coordinates of the labeled image, r 11 -r 32 is the unknown number to be solved, (x i ,y i ,z i ) is the converted three-dimensional second spatial coordinate. The first spatial coordinate obtained by the tracing device in the previous text can be a three-dimensional coordinate, while the first image taken by the C-arm machine is a two-dimensional image. Therefore, the second spatial coordinate of the marker image obtained by the first image is a two-dimensional coordinate. According to equation (1), the two-dimensional coordinate of the marker image can be converted into a three-dimensional coordinate (x i ,y i ,z i ), and make the three-dimensional second spatial coordinates of all the marker images coplanar. Wherein, i=1:m, m is the total number of spatial markers.

[0133] Equation (2) is the plane equation of the first imaging plane, where (x i ,y i ,z i ) is the three-dimensional second space coordinate after transformation according to equation (1), A, B, C, D are the coefficients of the plane equation, and are the unknowns to be solved. In equation (3), (x j ,y j ,z j ) represents the first spatial coordinate, which can be obtained by the tracing device, wherein, j = 1: m, m is the total number of spatial markers. (x0, y0, z0) represents the spatial coordinate of the intersection point, and is the unknown number to be solved. In equation (4), d represents the distance.

[0134] When solving the above equations, multiple first space coordinates (x j ,y j ,z j ), multiple two-dimensional second space coordinates (u i ,v i ) and the distance d into the equations, we can solve the unknowns in the equations and obtain the spatial coordinates of the intersection point (x0, y0, z0).

[0135] like Figure 7 As shown, (x j ,y j ,z j ) is the first spatial coordinate of the spatial marker 510, (x i ,y i ,z i ) is the three-dimensional second spatial coordinate of the marker image 610.

[0136] In some embodiments, when the spatial coordinates of the intersection are calculated using the above equation group, at least four spatial markers 510 and corresponding four marker images 610 are selected to calculate the spatial coordinates of the intersection.

[0137] In some embodiments, multiple spatial markers are arranged at equal intervals.

[0138] In some embodiments, multiple spatial markers are arranged in rows and columns, wherein the number of spatial markers in each row or column is different. Such a design is helpful to determine the correspondence between the spatial markers and the marker images.

[0139] In some embodiments, the shape formed by the multiple spatial markers is a right-angled trapezoid.

[0140] Combination Figure 6 As shown, according to the first image 601, in the coordinate system O2X2Y2, a plurality of spatial markers are arranged at equal intervals, and the plurality of spatial markers are 8 rows extending along the v1 direction and 4 columns extending along the v2 direction, wherein the number of spatial markers in each column is different, for example, from left to right, the number of spatial markers in each column is 7, 6, 5, and 4, respectively. Figure 6 The shape of the multiple space markers in the image is a right-angled trapezoid. According to such an embodiment, it is helpful to distinguish a single space marker according to the position, so as to accurately locate the first space coordinate and the corresponding second space coordinate.

[0141] In some embodiments, a plurality of spatial markers are disposed on a spatial marker plate, and the spatial marker plate is disposed in the imaging space.

[0142] In some embodiments, the material of the spatial marker plate is non-metal, such as plastic; and the material of the plurality of spatial markers includes metal, such as steel.

[0143] In some embodiments, the space marker includes a marker ball, the space marker plate includes a plurality of recessed portions, and the plurality of marker balls are respectively disposed in the plurality of recessed portions, such as Figure 5 In some embodiments, the recessed portion is a through hole.

[0144] According to the above method for obtaining the first position and / or the second position, the actual first spatial coordinates of the spatial marker in the imaging space and the second spatial coordinates in the first imaging plane are used, combined with the distance between the X-ray source and the first imaging plane, and the actual position of the X-ray source can be calculated by mathematical methods, which has the beneficial effects of simple calculation and accurate results. In addition, in some operations such as spinal surgery, a tracer device and a tracer marker are required. By combining a spatial marker plate with a spatial marker with the tracer device, the spatial positioning system in the tracer device can be reused, and the first spatial coordinates can be easily obtained.

[0145] It should be noted that in the intraoperative image matching method of the present invention, steps S120-S160 can be performed during the operation. Therefore, a spatial marker or a spatial marker plate including a spatial marker is set in the imaging space in advance, and the first X-ray image and the second X-ray image are respectively obtained by adjusting the X-ray light source position of the C-arm machine during the operation. The first position and the second position of the X-ray light source are obtained in real time according to the above method, and the optimal transformation parameters are obtained by an iterative method. The preoperative three-dimensional image can be quickly and accurately aligned to the intraoperative imaging space, which is conducive to precise navigation of the operation.

[0146] Figure 8 FIG. 1 is a block diagram of an intraoperative image matching system based on a C-arm machine according to an embodiment of the present invention. Figure 8 As shown, the intraoperative image matching system 800 includes a three-dimensional image acquisition unit 801 and a controller 802. The three-dimensional image acquisition unit 801 is used to acquire a preoperative three-dimensional image of the detected object. In some embodiments, the three-dimensional image acquisition unit 801 can be a CT device. The controller 802 is configured to perform the following steps:

[0147] Step S810: adjusting the X-ray source position of the C-arm machine to a first position, and photographing the detection object by the C-arm machine to obtain a first X-ray image;

[0148] Step S820: adjusting the position of the X-ray light source to a second position, photographing the detection object with a C-arm machine to obtain a second X-ray image, wherein there is an angle between the first position and the second position;

[0149] Step S830: rotating and / or translating the preoperative three-dimensional image to obtain a plurality of spatially transformed three-dimensional images, each of which has corresponding transformation parameters;

[0150] Step S840: Execute the following steps ac on part or all of the spatially transformed 3D image:

[0151] Step a: projecting the spatially transformed three-dimensional image into a first projection image according to the first position, and calculating a first similarity between the first projection image and the first X-ray image;

[0152] Step b: projecting the spatially transformed three-dimensional image into a second projection image according to the second position, and calculating a second similarity between the second projection image and the second X-ray image;

[0153] Step c: taking the transformation parameters of the spatially transformed three-dimensional image that meet the optimization condition as the optimal transformation parameters, wherein the optimization condition is set according to the first similarity and the second similarity;

[0154] Step S850: aligning the preoperative three-dimensional image to the intraoperative imaging space according to the optimal transformation parameters.

[0155] The intraoperative image matching system 800 of the present invention can be used to implement the intraoperative image matching method described above. Therefore, the description of the intraoperative image matching method described above can be used to describe the intraoperative image matching system 800, and the same content will not be expanded. It can be understood that in order to obtain the first position and the second position of the X-ray source in real time, the intraoperative image matching system 800 also includes a spatial marker set in the imaging space.

[0156] The intraoperative image matching system according to the present invention can easily and quickly obtain a spatially transformed three-dimensional image with optimal transformation parameters, thereby aligning the preoperative three-dimensional image to the intraoperative imaging space, which is beneficial for precise navigation during surgery.

[0157] The present invention also includes an intraoperative image matching device based on a C-arm machine, comprising a memory and a processor, wherein the memory is used to store instructions executable by the processor; and the processor is used to execute the instructions to implement the intraoperative image matching method based on a C-arm machine as described above.

[0158] Fig. 9 1 is a system block diagram of an intraoperative image matching device based on a C-arm machine according to an embodiment of the present invention. Fig. 9 As shown, the intraoperative image matching device 900 may include an internal communication bus 901, a processor 902, a read-only memory (ROM) 903, a random access memory (RAM) 904, and a communication port 905. When applied on a personal computer, the intraoperative image matching device 900 may also include a hard disk 906. The internal communication bus 901 can realize data communication between the components of the intraoperative image matching device 900. The processor 902 can make judgments and issue prompts. In some embodiments, the processor 902 can be composed of one or more processors. The communication port 905 can realize data communication between the intraoperative image matching device 900 and the outside. In some embodiments, the intraoperative image matching device 900 can send and receive information and data from the network through the communication port 905. The intraoperative image matching device 900 may also include different forms of program storage units and data storage units, such as a hard disk 906, a read-only memory (ROM) 903 and a random access memory (RAM) 904, which can store various data files used for computer processing and / or communication, and possible program instructions executed by the processor 902. The processor executes these instructions to implement the main part of the method. The result processed by the processor is transmitted to the user device through the communication port and displayed on the user interface.

[0159] The above-mentioned intraoperative image matching method can be implemented as a computer program, stored in the hard disk 906, and loaded into the processor 902 for execution to implement the intraoperative image matching method of the present application.

[0160] The present invention also includes a computer-readable medium storing a computer program code, which, when executed by a processor, implements the C-arm-based intraoperative image matching method described above.

[0161] When the intraoperative image matching method based on the C-arm is implemented as a computer program, it can also be stored in a computer-readable storage medium as a product. For example, a computer-readable storage medium may include, but is not limited to, a magnetic storage device (e.g., a hard disk, a floppy disk, a magnetic strip), an optical disk (e.g., a compact disk (CD), a digital versatile disk (DVD)), a smart card, and a flash memory device (e.g., an electrically erasable programmable read-only memory (EPROM), a card, a stick, a key drive). In addition, the various storage media described herein can represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media (and / or storage media) that can store, contain and / or carry code and / or instructions and / or data.

[0162] It should be understood that the embodiments described above are only illustrative. The embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or any combination thereof. For hardware implementation, the processor may be implemented in one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, and / or other electronic units designed to perform the functions described herein, or combinations thereof.

[0163] Some aspects of the present application may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". The processor may be one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or combinations thereof. In addition, various aspects of the present application may be expressed as computer products located in one or more computer-readable media, which include computer-readable program codes. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, tapes ...), optical disks (e.g., compact disks CDs, digital versatile disks DVDs ...), smart cards, and flash memory devices (e.g., cards, sticks, key drives ...).

[0164] A computer-readable medium may include a propagated data signal containing computer program code, such as in baseband or as part of a carrier wave. The propagated signal may have a variety of manifestations, including electromagnetic, optical, etc., or a suitable combination. A computer-readable medium may be any computer-readable medium other than a computer-readable storage medium, which may be connected to an instruction execution system, device or apparatus to communicate, propagate or transmit a program for use. The program code on the computer-readable medium may be propagated via any suitable medium, including radio, cable, fiber optic cable, radio frequency signal, or similar medium, or any combination of the above mediums.

[0165] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0166] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0167] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

Claims

1. A C-arm-based intraoperative image matching method, comprising: Acquire a preoperative three-dimensional image of the detected object; Adjusting the X-ray source position of the C-arm machine to a first position, and photographing the detection object by the C-arm machine to obtain a first X-ray image; Adjusting the position of the X-ray light source to a second position, photographing the detection object with the C-arm machine to obtain a second X-ray image, wherein there is an angle between the first position and the second position; Rotating and / or translating the preoperative three-dimensional image to obtain a plurality of spatially transformed three-dimensional images, each of the spatially transformed three-dimensional images having corresponding transformation parameters; Perform the following steps ac on part or all of the spatially transformed three-dimensional images: Step a: projecting the spatially transformed three-dimensional image into a first projection image according to the first position, and calculating a first similarity between the first projection image and the first X-ray image; Step b: projecting the spatially transformed three-dimensional image into a second projection image according to the second position, and calculating a second similarity between the second projection image and the second X-ray image; Step c: taking the transformation parameters of the spatially transformed three-dimensional image that meet the optimization condition as the optimal transformation parameters, wherein the optimization condition is set according to the first similarity and the second similarity; aligning the preoperative three-dimensional image to the intraoperative imaging space according to the optimal transformation parameters; The first position and / or the second position are obtained according to the following steps: The C-arm machine is used to shoot an imaging space to obtain a first image, wherein the imaging space includes a plurality of spatial markers, each of which has a first spatial coordinate, and the plurality of spatial markers correspond to a plurality of marker images in the first image, each of which has a second spatial coordinate, wherein the first image is located in a first imaging plane in the imaging space; Obtaining the distance between the X-ray source of the C-arm machine and the first imaging plane; and The X-ray source position of the C-arm machine is calculated according to the first spatial coordinate, the second spatial coordinate and the distance.

2. The intraoperative image matching method according to claim 1, characterized in that: The angle ranges from 45 degrees to 135 degrees.

3. The intraoperative image matching method according to claim 1, characterized in that: The transformation parameters include: one or any combination of: a rotation angle around the X-axis, a rotation angle around the Y-axis, a rotation angle around the Z-axis, a translation distance along the X-axis, a translation distance along the Y-axis, and a translation distance along the Z-axis, wherein the X-axis, the Y-axis, and the Z-axis are the spatial coordinate axes of the preoperative three-dimensional image.

4. The intraoperative image matching method according to claim 1, characterized in that: The first X-ray image is an upright image of the detected object, and the second X-ray image is a lateral image of the detected object.

5. The intraoperative image matching method according to claim 1, characterized in that: The pre-operative three-dimensional image is a segmented image, and the detection object is a region of interest of the surgical object.

6. The intraoperative image matching method according to claim 1, characterized in that: The optimization condition in step c includes: the sum or weighted sum of the first similarity and the second similarity is maximum.

7. An intraoperative image matching device based on a C-arm machine, comprising: a memory for storing instructions executable by a processor; A processor is used to execute the instructions to implement the method as described in any one of 1-6.

8. A computer-readable medium storing a computer program code, wherein the computer program code implements the method described in any one of 1 to 6 when executed by a processor.

9. An intraoperative image matching system based on a C-arm machine, comprising: A three-dimensional image acquisition unit, used for acquiring a preoperative three-dimensional image of the detected object; Controller, configured as: Adjusting the X-ray source position of the C-arm machine to a first position, and photographing the detection object by the C-arm machine to obtain a first X-ray image; Adjusting the position of the X-ray light source to a second position, photographing the detection object with the C-arm machine to obtain a second X-ray image, wherein there is an angle between the first position and the second position; Rotating and / or translating the preoperative three-dimensional image to obtain a plurality of spatially transformed three-dimensional images, each of the spatially transformed three-dimensional images having corresponding transformation parameters; Perform the following steps ac on part or all of the spatially transformed three-dimensional images: Step a: projecting the spatially transformed three-dimensional image into a first projection image according to the first position, and calculating a first similarity between the first projection image and the first X-ray image; Step b: projecting the spatially transformed three-dimensional image into a second projection image according to the second position, and calculating a second similarity between the second projection image and the second X-ray image; Step c: taking the transformation parameters of the spatially transformed three-dimensional image that meet the optimization condition as the optimal transformation parameters, wherein the optimization condition is set according to the first similarity and the second similarity; aligning the preoperative three-dimensional image to the intraoperative imaging space according to the optimal transformation parameters; The first position and / or the second position are obtained according to the following steps: The C-arm machine is used to shoot an imaging space to obtain a first image, wherein the imaging space includes a plurality of spatial markers, each of which has a first spatial coordinate, and the plurality of spatial markers correspond to a plurality of marker images in the first image, each of which has a second spatial coordinate, wherein the first image is located in a first imaging plane in the imaging space; Obtaining the distance between the X-ray source of the C-arm machine and the first imaging plane; and The X-ray source position of the C-arm machine is calculated according to the first spatial coordinate, the second spatial coordinate and the distance.

Images