Isocenter correction method, computer device, system and storage medium

Abstract

The application discloses an isocenter correction method, computer equipment, a system and a storage medium. The isocenter correction method comprises the following steps: acquiring a first image group, wherein the first image group comprises at least two images formed by a first ray and a second ray passing through a marker located at a first isocenter, the central ray of the first ray and the central ray of the second ray have a preset included angle; acquiring the position of the marker in the first image group; and correcting the position of the first isocenter according to the position of the marker in the first image group.

Description

Technical Field

[0001] This application relates to the field of medical device technology, specifically to an isocenter calibration method, computer equipment, system, and storage medium. Background Technology

[0002] Tumor radiotherapy requires four precisions: precise localization, precise planning, precise placement, and precise treatment. Precise isocenter coordinates of the radiotherapy device are a crucial indicator of radiotherapy quality assurance.

[0003] However, the isocenter coordinates measured manually are not accurate enough, so precise calibration of the isocenter is required. Summary of the Invention

[0004] This application provides an isocenter correction method, computer device, system, and storage medium, which can correct the isocenter to obtain accurate isocenter coordinate positions.

[0005] On one hand, this application provides an isocenter correction method, the method comprising: acquiring a first image group, the first image group comprising at least two images formed by a first ray and a second ray through a marker located at a first isocenter, wherein the central ray of the first ray and the central ray of the second ray have a preset angle; acquiring the position of the marker in the first image group; and correcting the position of the first isocenter according to the position of the marker in the first image group.

[0006] In a second aspect, this application also provides a computer device comprising: one or more processors; a memory; and one or more application programs, wherein the one or more application programs are stored in the memory and configured to be executed by the processor to implement the steps in the isocenter correction method described in any one aspect.

[0007] Thirdly, this application also provides an isocenter correction system, the system comprising: a marker detachably fixed at a first isocenter of a radiotherapy device, the center of the marker coinciding with the first isocenter; at least one set of imaging devices, each set of imaging devices comprising an imaging source and an imager disposed opposite to each other, a first ray and a second ray emitted by the imaging source being received by the imager via the marker, the central ray of the first ray and the central ray of the second ray having a preset angle; and a computer device as described in any of the second aspects, connected to the imager.

[0008] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, the computer program being loaded by a processor to perform the steps in the isocenter correction method according to any one of the first aspects.

[0009] The isocenter correction method in this application embodiment can first acquire a first image group, which includes at least two images formed by a first ray and a second ray through a marker located at the first isocenter, and the central ray of the first ray and the central ray of the second ray have a preset angle; then acquire the position of the marker in the first image group; finally, based on the position of the marker in the first image group, correct the position of the first isocenter to obtain an accurate isocenter position. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1A This is a schematic diagram of an embodiment of the isocenter correction system provided in this application.

[0012] Figure 1B This is a schematic diagram of another embodiment of the isocenter correction system provided in this application.

[0013] Figure 2 This is a schematic flowchart of an embodiment of the isocenter correction method provided in this application.

[0014] Figure 3 This is a schematic flowchart of another embodiment of the isocenter correction method provided in this application.

[0015] Figure 4 This is a schematic diagram illustrating the positional relationship between the imaging device and the isocenter in a specific example of the isocenter correction method provided in this application embodiment;

[0016] Figure 5 This is a schematic diagram illustrating the transformation relationship between the first image coordinate system X1-Y1 and the first pixel coordinate system U1-V1 provided in the embodiments of this application;

[0017] Figure 6 This refers to the imaging geometry of the first ray provided in this embodiment, corresponding to the Y-axis direction in the IEC coordinate system.

[0018] Figures 7A-7D These are the eight isocenter offset scenarios provided in the embodiments of this application;

[0019] Figure 8 This is a distribution map of the eight isocenter offsets provided in the embodiments of this application in the quadrants;

[0020] Figure 9 This is the first imaging geometric relationship between the first ray and the second ray provided in the embodiments of this application, corresponding to the planes in the X-axis direction and the Z-axis direction;

[0021] Figure 10A and 10B This is the second imaging geometric relationship provided in the embodiments of this application, where the first ray and the second ray correspond to the planes in the X-axis and Z-axis directions;

[0022] Figure 11 This is a schematic diagram of an embodiment of the computer device provided in this application. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application 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 this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," or "third" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use this application. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be made without using these specific details. In other instances, well-known structures and processes are not described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0026] It should be noted that since the method in this application embodiment is executed in a computer device, the processing objects of each computer device exist in the form of data or information, such as time, which is essentially time information. It is understood that if size, quantity, position, etc. are mentioned in subsequent embodiments, they are all corresponding data that exist so that the computer device can process them. Specific details will not be elaborated here.

[0027] Please refer to Figure 1A , Figure 1A This is a schematic diagram of an embodiment of the isocenter correction system provided in this application. The system 10 is used for isocenter correction of a radiotherapy device 20 and may include: markers 11, at least one set of imaging devices 12, and computer equipment 13. Wherein:

[0028] The radiotherapy device 20 can perform radiotherapy on a target object, such as a patient's target point or target area. The radiotherapy device 20 may include a gantry 201, a radiotherapy head 202 mounted on the gantry 201, and a support device 203 for supporting the patient. Here, the gantry 201 may be as follows: Figure 1A The ring-shaped gantry shown can also be a C-arm, drum-shaped, or other type of gantry. The radiotherapy head 202 can be a gamma knife radiotherapy head, an accelerator radiotherapy head, a proton therapy head, or other radiotherapy heads. The support device 203 can be a bed, a chair, or other similar devices.

[0029] The marker 11 is detachably fixed at the initial isocenter (i.e., the first isocenter) O of the radiotherapy device 20, and the center of the marker 11 can coincide with the first isocenter O of the radiotherapy device 20. The marker 11 can be shaped like a sphere or a cube, and the material of the marker 11 can be metal, such as aluminum, tungsten, or steel.

[0030] At least one imaging device 12 can acquire real-time images of the patient. This device can be an imaging component within the radiotherapy device 20, such as an image guiding device, or a separate component. The imaging device 12 includes an imaging source 121 and an imager 122 positioned opposite each other. A first ray and a second ray emitted from the imaging source 121 are received by the imager 122 via a marker 11. The central rays of the first ray and the central rays of the second ray have a preset angle, which is greater than 0 degrees and less than 180 degrees.

[0031] It should be noted that the imaging device 12 can be as follows: Figure 1A The device is mounted on the frame 201 as shown, or it can be mounted separately on a bracket for supporting the imaging device 12. The bracket can be a fixed bracket that cannot rotate, or it can be a rotating bracket, such as a ring-shaped rotating bracket.

[0032] The imaging source 121 is typically an imaging radiation source, such as an X-ray source like a x-ray tube. The X-rays emitted by the X-ray source are in the KV range and can be a cone beam. The imager 122 is an imager that receives the KV-level radiation emitted by the imaging X-ray source. It can be a detector, such as a flat panel detector or an arc-shaped imager. Here, the imaging device consisting of a KV-level x-ray tube and a corresponding flat panel imager is also called CBCT.

[0033] To obtain images from different imaging angles, the imaging device 12 can be in two sets, such as... Figure 1B As shown, the two imaging devices include a first imaging source 121A and a first imager 122A disposed opposite to the first imaging source 121A, a second imaging source 121B and a second imager 122B disposed opposite to the second imaging source 121B. The first imaging source 121A and the second imaging source 121B emit a first ray and a second ray, respectively. For example, the imaging device 12 is two CBCTs. Of course, the imaging device 12 can also rotate and emit the first ray and the second ray at different rotation angles. For example, the imaging device 12 is mounted on a gantry 201, and the gantry 201 can drive the imaging device 12 to rotate.

[0034] Computer device 13 can be connected to imaging device 12. Computer device 13 can control imaging source 121 in imaging device 12 to image marker 11 located at first isocenter O of imaging device 12. Computer device 13 can also acquire at least two images formed by first ray and second ray passing through marker 11 located at first isocenter O.

[0035] In this embodiment, the computer device 13 can be a general-purpose computer device or a special-purpose computer device. In specific implementations, the computer device can be a desktop computer, a portable computer, a network server, a PDA (Personal Digital Assistant), a mobile phone, a tablet computer, a wireless terminal device, a communication device, an embedded device, etc. This embodiment does not limit the type of computer device.

[0036] In the embodiments of this application, the computer device 13 and the imaging device 12 can communicate through any communication method, including but not limited to mobile communication based on 2G, 3G, 4G, 5G, Long Term Evolution (LTE), Worldwide Interoperability for Microwave Access (WiMAX), or computer network communication based on TCP / IP Protocol Suite (TCP / IP), User Datagram Protocol (UDP), or communication based on the Digital Imaging and Communications in Medicine (DICOM) medical information standard.

[0037] Those skilled in the art will understand that Figure 1A and Figure 1B The system shown is merely one application scenario of the present application and does not constitute a limitation on the application scenario of the present application. Other application environments may include more. Figure 1A and Figure 1B The system may include more or fewer computer devices as shown, and it is understood that the system may also include one or more other computer devices capable of processing data, such as a Treatment Planning System (TPS), an Oncology Information System (OIS), etc., which are not specifically limited here.

[0038] In this embodiment, the system 10 may further include a carrier 14, through which the marker 11 can be detachably mounted at the first isocenter O of the imaging device. The marker 11 may be located within the carrier 14, either fixedly embedded within it or detachably connected to it. The carrier 14 may be a mold, with a shape that is cube-shaped, spherical, or other. It may also be another device, such as a bracket for holding the marker 11. The carrier 14 may be mounted on a support device 203, which moves the marker 11 within the carrier 14 to the first isocenter O.

[0039] In addition, the material of the carrier 14 can be any material that is easily distinguishable from the marker 11, such as plexiglass, acrylic, etc.

[0040] It should be noted that the system 10 has a three-dimensional coordinate system, which can be the IEC coordinate system. The origin of the three-dimensional coordinate system is the isocenter O. The X-axis (i.e., the width direction of the support device 203, with the direction indicated by the arrow being positive), the Y-axis (i.e., the length direction of the support device 203, with the head / head direction being positive and the foot / foot direction being negative), and the Z-axis (i.e., the height direction of the support device 203, with the direction indicated by the arrow being positive) are mutually perpendicular, and the Y-axis coincides with the rotation axis A.

[0041] It should be noted that, Figure 1A and Figure 1B The schematic diagram of the radiotherapy system shown is merely an example. The radiotherapy system and scenarios described in the embodiments of this application are intended to more clearly illustrate the technical solutions of the embodiments of this application and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of radiotherapy systems and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0042] First, this application provides an isocenter correction method, wherein the processor in a computer device is the execution subject of the isocenter correction method. Figure 2 This is a schematic flowchart of an embodiment of the isocenter correction method provided in this application, as shown below. Figure 2 As shown, the center correction method includes the following steps S201 to S203, as detailed below:

[0043] S201. Acquire a first image group, the first image group including at least two images formed by a first ray and a second ray through a marker located at a first isocenter.

[0044] The computer device acquires a first image group, which includes at least two images formed by a first ray and a second ray through a marker located at a first isocenter, wherein the central ray of the first ray and the central ray of the second ray have a predetermined angle.

[0045] It should be noted that the marker is located at the first isocenter, which can be the initial mechanical isocenter of the radiotherapy device, i.e., the initial isocenter or the isocenter to be calibrated. The position of the first isocenter can be determined after the radiotherapy device is installed. Understandably, the position of the first isocenter is known, so the marker can be set at that first isocenter.

[0046] Here, the position of the first isocenter can be a three-dimensional coordinate position, such as the coordinates in the IEC coordinate system, or the coordinates in other coordinate systems.

[0047] It should also be noted that the images in the first image group are obtained by imaging a marker located at the first isocenter position using different rays and a second ray (i.e., different rays) with a preset angle. Each image in the first image group includes the projection of the marker. After the first isocenter is corrected, the center of the marker in each image should be located at the center of the image.

[0048] In addition, the angle between the central ray of the first ray and the central ray of the second ray is preset. The preset angle can be greater than 0 degrees and less than 180 degrees, such as 80 degrees, 90 degrees or 110 degrees.

[0049] S202, Obtain the position of the marker in the first image group.

[0050] After the computer device acquires the first image group, it needs to obtain the position of the marker in the first image group. Here, the position of the marker in the first image group can be understood as the position of the marker in each image in the first image group.

[0051] S203. Correct the position of the first isocenter based on the position of the marker in the first image group.

[0052] Since the position of the first isocenter is obtained by manual measurement, the position of the first isocenter (the initial isocenter position) may not be an accurate isocenter position. Therefore, computer equipment can correct the position of the first isocenter based on the position of the marker in the first image group to obtain an accurate isocenter position.

[0053] The isocenter correction method in this application embodiment can first acquire a first image group and acquire the position of the first isocenter. The first image group includes at least two images formed by a first ray and a second ray passing through a marker located at the first isocenter. Then, the position of the marker in the first image group is acquired. Finally, the position of the first isocenter is corrected according to the position of the marker in the first image group, thereby obtaining an accurate isocenter position.

[0054] This invention also provides another isocenter correction method, please refer to... Figure 3 , Figure 3 This is a schematic flowchart of another embodiment of the isocenter correction method provided in this application. The isocenter correction method is applied to a processor in a computer device and may include:

[0055] S301. Obtain a first image group, the first image group including at least two images formed by a first ray and a second ray through a marker located at a first isocenter, including a first image and a second image.

[0056] This step has already been explained in step S201, and will not be repeated here.

[0057] S302. Obtain the coordinates of the marker in the first image in the first image coordinate system and the coordinates of the marker in the second image in the second image coordinate system.

[0058] After acquiring the first image group, the computer device can obtain the position of the marker within the first image group. Here, if the first image group includes a first image and a second image, the position of the marker within the first image group includes the coordinates of the marker in the first image in the first image coordinate system and the coordinates of the marker in the second image in the second image coordinate system.

[0059] It should be noted that both the first and second image coordinate systems are image coordinate systems, and image coordinate systems are two-dimensional coordinate systems. The first and second image coordinate systems can be the same image coordinate system or different image coordinate systems.

[0060] When the imaging devices are a set, the first image coordinate system and the second image coordinate system are the same image coordinate system. Accordingly, step S302 can specifically include:

[0061] S302a1. Obtain the coordinates of the marker in the first image in the pixel coordinate system and the coordinates of the marker in the second image in the pixel coordinate system, wherein the pixel coordinate system is the coordinate system corresponding to the pixel array of the imager.

[0062] S302a2. Based on the transformation relationship between the image coordinate system and the pixel coordinate system, the coordinates of the marker in the first image in the pixel coordinate system are converted to the coordinates of the marker in the first image in the image coordinate system, and the coordinates of the marker in the second image in the pixel coordinate system are converted to the coordinates of the marker in the second image in the image coordinate system, wherein the image coordinate system is the coordinate system corresponding to the first image and the second image.

[0063] When the imaging device consists of two sets, the imaging source includes a first imaging source and a second imaging source. Correspondingly, it includes a first detector positioned opposite the first imaging source and a second detector positioned opposite the second imaging source. The first and second imaging sources emit a first ray and a second ray, which are received by the first and second detectors respectively after passing through a marker. Accordingly, step S302 can specifically include:

[0064] S302b1. Obtain the coordinates of the marker in the first image in the first pixel coordinate system, where the first pixel coordinate system is the coordinate system corresponding to the pixel array of the first imager.

[0065] S302b2: Obtain the coordinates of the marker in the second image in the second pixel coordinate system, which is the coordinate system corresponding to the pixel array of the second imager.

[0066] S302b3. Based on the transformation relationship between the first image coordinate system and the first pixel coordinate system, the coordinates of the marker in the first image in the first pixel coordinate system are converted to the coordinates of the marker in the first image in the first image coordinate system, wherein the first image coordinate system is the coordinate system corresponding to the first image.

[0067] S302b4. Based on the transformation relationship between the second image coordinate system and the second pixel coordinate system, the coordinates of the marker in the second image in the second pixel coordinate system are converted to the coordinates of the marker in the second image in the second image coordinate system, where the second image coordinate system is the coordinate system corresponding to the second image.

[0068] It should be noted that the transformation relationship between the image coordinate system and the pixel coordinate system is preset. For example, the origin of the pixel coordinate system can indicate the top left pixel of the detector pixel array, and the horizontal and vertical coordinates indicate the column and row of the detector pixel array, respectively. The origin of the image coordinate system is the center pixel of the detector pixel array in the pixel coordinate system.

[0069] The following steps S303 to S311 will describe a specific method for correcting the position of the first isocenter based on the position of the marker in the first image group. Step S303 can correct the coordinates of the first isocenter in the Y-axis direction in the IEC coordinate system to obtain the position of the second isocenter, that is, the isocenter after correction by X-axis imitation. Steps S304 to S311 can correct the coordinates of the second isocenter in the X-axis and Z-axis directions in the IEC coordinate system to obtain the position of the third isocenter, that is, the corrected isocenter.

[0070] S303. Based on the coordinates of the markers in the first image in the first image coordinate system and the coordinates of the markers in the second image in the second image coordinate system, the coordinates of the first isocenter in the Y-axis direction in the IEC coordinate system are corrected to obtain the position of the second isocenter.

[0071] The computer device can correct the coordinates of the first isocenter in the IEC coordinate system based on the coordinates of the markers in the first image in the first image coordinate system and the coordinates of the markers in the second image in the second image coordinate system, to obtain the position of the second isocenter, which is the isocenter position after the first correction. Here, the first direction is parallel to the Y-axis direction.

[0072] In this embodiment of the application, step S303 may specifically include:

[0073] S3031. Based on the coordinates of the marker in the first image in the first image coordinate system, and the imaging geometry corresponding to the first ray in the Y-axis direction of the IEC coordinate system, determine the first isocenter offset in the Y-axis direction of the IEC coordinate system. This imaging geometry can be the first isocenter offset in the Y-axis direction of the IEC coordinate system, the Y1-axis coordinate of the marker in the first image in the first image coordinate system (parallel to the Y-axis direction of the IEC coordinate system), and the geometric relationship between the distance from the first imaging source to the isocenter and the distance from the first imaging source to the first imager.

[0074] S3032. Based on the coordinates of the marker in the second image in the second image coordinate system, and the imaging geometry of the second ray corresponding to the Y-axis direction in the IEC coordinate system, determine the second isocenter offset in the Y-axis direction in the IEC coordinate system. This imaging geometry can be the first isocenter offset in the Y-axis direction in the IEC coordinate system, the Y2-axis coordinate of the marker in the second image in the second image coordinate system (parallel to the Y-axis direction in the IEC coordinate system), and the geometric relationship between the distance from the second imaging source to the isocenter and the distance from the second imaging source to the second imager.

[0075] S3033. Based on the first and second center offsets, correct the Y-axis coordinates of the first center position in the IEC coordinate system to obtain the position of the second center.

[0076] Here, the position of the second isocenter can be obtained by correcting the Y-axis coordinate of the first isocenter in the IEC coordinate system based on the average of the first and second isocenter offsets.

[0077] S304. Acquire a second image set, the second image set including at least two images formed by the first ray and the second ray through a marker located at a second isocenter, including a third image and a fourth image.

[0078] This step is similar to step S301, and will not be repeated here.

[0079] S305. Obtain the coordinates of the marker in the third image in the first image coordinate system and the coordinates of the marker in the fourth image in the second image coordinate system.

[0080] This step is similar to step S302, and will not be repeated here.

[0081] S306. Determine whether the markers in the third and fourth images are located at the center of the images.

[0082] In this embodiment, the computer device also needs to determine whether the markers in the third and fourth images are located at the center of the image. If it is determined that the markers in both the third and fourth images are located at the center of the image, it indicates that no correction is needed for the isocenter offset in the X-axis and Z-axis directions; if it is determined that the markers in neither the third nor the fourth image are located at the center of the image, it indicates that the isocenter offset in the X-axis and Z-axis directions needs to be corrected, and steps S307 and S308 are executed; if it is determined that the markers in either the third or fourth image are located at the center of the image, it indicates that the isocenter offset in the X-axis and Z-axis directions needs to be corrected, and steps S309 to S311 are executed.

[0083] S307. Based on the coordinates of the marker in the first image coordinate system corresponding to the third image, the coordinates of the marker in the second image coordinate system corresponding to the fourth image, and the first imaging geometric relationship between the first ray and the second ray in the planes located in the X-axis and Z-axis directions of the IEC coordinate system, determine the isocenter offset in the X-axis and Z-axis directions of the IEC coordinate system.

[0084] S308. Based on the isocenter offset in the X-axis and Z-axis directions in the IEC coordinate system, correct the coordinates of the second isocenter in the X-axis and Z-axis directions in the IEC coordinate system to obtain the position of the third isocenter.

[0085] If it is determined that the markers in the third and fourth images are not located in the center of the image, the isocenter position can be accurately corrected through steps S307 and S308 to obtain the accurate isocenter position.

[0086] S309. Based on the angle between the central ray of the target ray and the Z-axis, the coordinates of the marker in the corresponding image coordinate system are decomposed into the offsets of the marker in the X-axis and Z-axis directions of the corresponding image coordinate system. The target ray includes a first ray or a second ray.

[0087] S310. Based on the offset of the marker in the X-axis and Z-axis directions of the corresponding image coordinate system, and the second imaging geometric relationship of the first ray and the second ray in the planes where the X-axis and Z-axis directions of the IEC coordinate system are located, determine the isocenter offset in the X-axis and Z-axis directions of the IEC coordinate system.

[0088] S311. Based on the isocenter offset in the X-axis and Z-axis directions in the IEC coordinate system, correct the coordinates of the second isocenter in the X-axis and Z-axis directions in the IEC coordinate system to obtain the position of the third isocenter.

[0089] Through the above steps S301 to S311, the coordinates of the first isocenter (initial isocenter) can be corrected, thereby obtaining the accurate coordinates of the isocenter.

[0090] This invention also provides a specific example of an isocenter correction method, in which, for example... Figure 4 As shown, the imaging device consists of two sets, including: a first X-ray source S1 and a first detector A arranged opposite to it, and a second X-ray source S2 and a second detector B arranged opposite to it. The isocenter O is the mechanical isocenter of the radiation device, which is the intersection point of the central ray S1O of the first X-ray emitted from the first X-ray source S1 and the central ray S2O of the second X-ray emitted from the second X-ray source S2. The central ray S1O of the first X-ray and the central ray S2O of the second X-ray are perpendicular to the first detector A and the second detector B, respectively, and their intersection point is the center of the first detector A and the second detector B, respectively. Here, there is a predetermined angle between the central ray S1O of the first X-ray and the central ray S2O of the second X-ray. If the marker is located at the isocenter O, the first ray emitted by the first X-ray source S1 is received by the first detector A via the marker at isocenter O, and the second ray emitted by the second X-ray source S2 is received by the second detector B via the same marker. Correspondingly, the projections O1 and O2 of the marker onto the first detector A and the second detector B are located at the centers of the first detector A and the second detector B, respectively. However, the manually measured isocenter position is not precise and needs to be corrected to determine the accurate isocenter position.

[0091] Based on this, the center correction method may include:

[0092] S501. Obtain a first image group, which includes a first image and a second image formed by a marker located at a first isocenter O'(X0,Y0,Z0) of a first ray and a second ray, respectively. The central ray S1O of the first ray and the central ray S2O of the second ray have a preset angle. Specifically:

[0093] Computer equipment controls the first X-ray source S1 and the second X-ray source S2 to emit first and second rays respectively through a marker located at the first isocenter O' to the first detector A and the second detector B. The computer then acquires two projected images of the marker from the first detector A and the second detector B, forming the first image and the second image, respectively. Here, the first isocenter O' is a manually determined position, which will be corrected later.

[0094] S502. Obtain the coordinates O′1(x1,y1) of the marker in the first image in the first image coordinate system X1-Y1, and the coordinates O′2(x2,y2) of the marker in the second image in the second image coordinate system X2-Y2. Specifically:

[0095] The computer device automatically obtains the center pixel coordinates O1(u1,v1) of the marker in the first image in the first pixel coordinate system U1-V1 and the center pixel coordinates O2(u2,v2) of the marker in the second image in the second pixel coordinate system U2-V2 according to the image processing algorithm. Based on the transformation relationship between the first image coordinate system X1-Y1 and the first pixel coordinate system U1-V1 and the second image coordinate system X2-Y2 and the second pixel coordinate system U2-V2, the computer device converts the center pixel coordinates O1(u1,v1) of the marker in the first image in the first pixel coordinate system U1-V1 to the coordinates O′1(x1,y1) of the marker in the first image in the image coordinate system X1-Y1, and converts the center pixel coordinates O2(u2,v2) of the marker in the second image in the second pixel coordinate system U2-V2 to the coordinates O′2(x2,y2) of the marker in the second image in the image coordinate system X2-Y2.

[0096] Here, as Figure 5 As shown, the origin of the first pixel coordinate system U1-V1 is O0(0,0), and the horizontal coordinate U1 and vertical coordinate V1 indicate the column and row of the first image, respectively. The origin of the first image coordinate system X1-Y1 is O1(0,0), and the coordinates of O1 in the first pixel coordinate system U1-V1 are O1(u0,v0), which is the midpoint of the pixel array corresponding to the pixel coordinate system. The transformation relationship between the first image coordinate system X1-Y1 and the first pixel coordinate system U1-V1 is as follows:

[0097] x1=(u1-u o )×d x

[0098] y1=(v1-v o )×d y

[0099] Where (x1, y1) are the coordinates of the marker in the first image in the X1-Y1 coordinate system, (u1, v1) are the coordinates of the marker in the first image in the U1-V1 coordinate system, and d x and d y These are the physical dimensions of each pixel in the detector pixel array on the horizontal axis X1 and the vertical axis Y1 of the image coordinate system, respectively.

[0100] The transformation relationship between the second image coordinate system X2-Y2 and the second pixel coordinate system U2-V2 is similar to the transformation relationship between the first image coordinate system X1-Y1 and the first pixel coordinate system U1-V1, and will not be repeated here.

[0101] S503. Based on O′1(x1,y1) and O′2(x2,y2), correct the Y-axis coordinates of the position O′(X0,Y0,Z0) of the first isocenter to obtain the position O″(X0,Y0,Z0) of the second isocenter. Specifically:

[0102] The Y-axis coordinates of the first isocenter in the IEC coordinate system can be determined based on the coordinates O′1(x1,y1) of the marker in the first image in the first image coordinate system X1-Y1 and the coordinates O′2(x2,y2) of the marker in the second image in the second image coordinate system X2-Y2.

[0103] Based on the coordinates O′1(x1,y1) of the marker in the first image in the first image coordinate system X1-Y1, and as follows Figure 6 The first ray shown corresponds to the imaging geometry along the Y-axis in the IEC coordinate system. The first isocenter offset along the Y-axis in the IEC coordinate system is determined as ΔY1 = y1 * (SAD1 / SID1), where y1 is the Y1-axis coordinate of the marker in the first image in the first image coordinate system X1-Y1, SAD1 is the distance from the first X-ray source S1 to the isocenter O, and SID1 is the distance from the first X-ray source S1 to the first detector A. The sign of ΔY1 is the same as that of y1.

[0104] Similarly, based on the coordinates O′2(x2,y2) of the marker in the second image in the second image coordinate system X2-Y2, and the imaging geometry of the second ray in the Y-axis direction of the IEC coordinate system, the second isocenter offset in the Y-axis direction of the IEC coordinate system is determined as ΔY2=y2*(SAD2 / SID2), where y2 is the Y2-axis coordinate of the marker in the second image in the second image coordinate system X2-Y2, SAD2 is the distance from the second X-ray source S2 to the isocenter O, and SID2 is the distance from the second X-ray source S2 to the second detector B. The sign of ΔY2 is the same as that of y2.

[0105] If both sets of X-ray sources and detectors are installed in place, the values ​​of y1 and y2 will be very close. Based on the first isocenter offset ΔY1 and the second isocenter offset ΔY2, the coordinate Y0 of the first isocenter position O'(X0,Y0,Z0) in the Y-axis direction of the IEC coordinate system is corrected. The Y0 in the first isocenter position O′(X0,Y0,Z0) is updated to Y1=Y0+(ΔY1+ΔY2) / 2, and the new second isocenter position O”(X0,Y1,Z0) is obtained.

[0106] The coordinates of the X and Z axes in the position of the second isocenter O (or the first isocenter) will be corrected below.

[0107] S504. Acquire a second image group, which includes a third and a fourth image formed by the first and second rays through markers located at the second isocenter O (X0, Y1, Z0).

[0108] S505. Obtain the coordinates O′1(x3,y3) of the marker in the third image in the first image coordinate system X1-Y1 and the coordinates O′2(x4,y4) of the marker in the fourth image in the second image coordinate system X2-Y2.

[0109] Next, the coordinates of the second isocenter position O””X0,Y1,Z0” in the X-axis and Z-axis directions will be corrected based on the coordinates O′1(x3,y3) of the marker in the third image in the first image coordinate system X1-Y1 and the coordinates O′2(x4,y4) of the marker in the fourth image in the second image coordinate system X2-Y2.

[0110] S506. Based on O′1(x3,y3) and O′2(x4,y4), correct the coordinates of the X-axis and Z-axis in the position O”(X0,Y1,Z0) of the second isocenter to obtain the position O1(X1,Y1,Z1) of the third isocenter, which is the corrected isocenter. Specifically, this includes:

[0111] (1) Determine the quadrant position of the coordinate offset of the second isocenter O” in the X-axis and Z-axis directions in the IEC coordinate system.

[0112] like Figures 7A to 7D The eight isocenter offset cases shown are viewed along the Y-axis of the IEC coordinate system. Arrows X1 and X2 represent the X-direction of the image coordinate system, while O1 and O2 are the origin of the image coordinate system. The specific quadrant distribution of the second isocenter O” is shown in Table 1 below:

[0113]

[0114]

[0115] Table 1

[0116] After obtaining O′1(x3,y3) and O′2(x4,y4), the unique quadrant distribution position of the second isocenter O” is determined by looking up Table 1 above based on the positive and negative signs and the magnitude of x3 and x4. Thus, the offset direction of the second isocenter O” can be confirmed based on the quadrant distribution position.

[0117] according to Figure 8As shown, for the first detector A, with the central ray (main beam) S1O of the first ray as the dividing line, the second isocenters 1, 2, 3, and 4 are located to the right of the central ray of the first ray. That is, when the second isocenters are offset from 1, 2, 3, and 4, their x3 coordinates are all less than 0. The second isocenters 5, 6, 7, and 8 are located to the left of the central ray of the first ray. That is, when the second isocenters are offset from 5, 6, 7, and 8, their x3 coordinates are all greater than 0. The second detector B is similar, and will not be described further here.

[0118] (2) Correct the coordinates of the X-axis and Z-axis in the position of the second isocenter.

[0119] Case 1: If it is determined that the markers in both the third and fourth images are not located at the center of the image, then based on the coordinates O′1(x3,y3) of the marker in the third image in the first image coordinate system X1-Y1 and the coordinates O′2(x4,y4) of the marker in the fourth image in the second image coordinate system X2-Y2, and as follows... Figure 9 The first and second rays shown correspond to the first imaging geometric relationship in the planes containing the X-axis and Z-axis directions. The isocenter offsets ΔX and ΔZ in the X-axis and Z-axis directions are determined. Then, based on the isocenter offsets ΔX and ΔZ, the coordinates in the X-axis and Z-axis directions of the position O"(X0,Y1,Z0) of the second isocenter are corrected to obtain the position O″′(X1,Y1,Z1) of the third isocenter, which is the final isocenter position.

[0120] Specifically, such as Figure 9 As shown, assume that the image coordinates of the marker projection are obtained as O′1(x3,y3) and O′2(x4,y4), where x3>0, x4<0, and |x3|<|x4|. Therefore, the isocenter O offset position (i.e., the second isocenter O”) is located in the fourth quadrant (lower), where the isocenter offset X>0 and Z<0.

[0121] Where O1O′1 / / OP1 / / H1O″, and O1O′1, OP1, and H1O″ are all perpendicular to S1O, with the feet of the perpendiculars being O1, O, and H1, respectively. Similarly, O2O′2 / / OP2 / / H2O″, and O2O′2, OP2, and H2O″ are all perpendicular to S2O, with the feet of the perpendiculars being O2, O, and H2, respectively. Let ∠O′OZ_ = θ, O″O = L, then

[0122] In right triangle ΔO″H1O, OH1 = L*cosθ1, O″H1 = L*sinθ1. In right triangle ΔO″H2O, OH2 = L*cosθ2, O″H2 = L*sinθ2.

[0123] According to the similarity principle of triangles ΔS1OP1 and ΔS1H1O″, we know that

[0124]

[0125] Based on the similarity between triangles ΔS2OP2 and ΔS1H2O″:

[0126]

[0127] in, O1O′1 and O2O′2 can be directly obtained from O′1(x3,y3) and O′2(x4,y4). SAD1, SID1, SAD2, and SID2 can be obtained from the mechanical design as initial calculations, or from measurements of the X-ray source and detector during installation. Therefore, OP1 and OP2 are known quantities, and the above two formulas can be expressed as:

[0128]

[0129]

[0130] Combining the above two formulas, we can obtain L and θ, and thus directly calculate the isocenter offset ΔX = L * sinθ and ΔZ = L * cosθ. Based on the projected coordinates and signs, the isocenter offset is located in the fourth quadrant. Therefore, the coordinates of the X-axis and Z-axis in the corrected position of the second isocenter, i.e., the third isocenter, are:

[0131] X1 = X0 - L*sinθ

[0132] Z1=Z0+L*cosθ

[0133] Thus, the final corrected isocenter O”'(X1,Y1,Z1) is obtained.

[0134] The offsets for other quadrants can also be calculated using this method, which will not be elaborated here.

[0135] In (2), the markers in the third and fourth images are not located at the center of the image. Therefore, based on the coordinates O′1(x3,y3) of the marker in the third image in the first image coordinate system X1-Y1 and the coordinates O′2(x4,y4) of the marker in the fourth image in the second image coordinate system X2-Y2, and for example... Figure 9 The first and second rays shown correspond to the first imaging geometric relationship in the planes containing the X-axis and Z-axis directions of the IEC coordinate system, and determine the isocentric offset in the X-axis and Z-axis directions of the IEC coordinate system.

[0136] The second scenario: If it is determined that the markers in the third or fourth image are all located at the center of the image, firstly, based on the angle between the central ray of the target ray and the Z-axis, the coordinates of the markers in the corresponding image coordinate system are decomposed into the offsets of the markers in the X-axis and Z-axis directions in the corresponding image coordinate system. The target ray includes either the first ray or the second ray. Then, based on the offsets of the markers in the X-axis and Z-axis directions in the corresponding image coordinate system, and the second imaging geometric relationship of the first ray and the second ray corresponding to the planes in the X-axis and Z-axis directions of the IEC coordinate system as shown in Figure 10, the isocenter offsets ΔX and ΔZ in the X-axis and Z-axis directions are determined. Finally, based on the isocenter offsets ΔX and ΔZ in the X-axis and Z-axis directions, the coordinates in the X-axis and Z-axis directions of the second isocenter position O″(X0,Y1,Z0) are corrected to obtain the position of the third isocenter O″′(X1,Y1,Z1), which is the final isocenter position.

[0137] Specifically, in the first example, such as Figure 10A As shown, the second isocenter O″ is located in the first or third quadrant. The first ray passes through the marker located at the second isocenter O″ to form a third image, and the second ray passes through the marker located at the second isocenter O″ to form a fourth image. The marker in the third image is not at the center of the third image, while the marker in the fourth image is at the center of the fourth image. In this case, according to the angle between the central ray S1O of the first ray and the Z-axis... The marker coordinate x3 is decomposed into offsets d in the X and Z axes. x3 and d z3 :

[0138]

[0139]

[0140] Then take the offset d on the first detector A x3 and d z3 The derivation to the isocenter position is based on the offset d of the marker in the X-axis and Z-axis directions. x3 and d z3 and such Figure 10A The first and second rays shown correspond to the second imaging geometry A in the planes containing the X-axis and Z-axis directions, respectively. The isocentric offsets ΔX1 and ΔZ1 in the X-axis and Z-axis directions are determined as follows:

[0141]

[0142]

[0143] As can be seen from the above formula, the signs of ΔX1 and ΔZ1 can be determined based on the positive or negative sign of x3.

[0144] If x3>0, the isocenter offset is located in the third quadrant, then ΔX1>0, ΔZ1>0, which means it needs to move in the positive X direction (to the right) of the IEC coordinate system and in the positive Z direction (up) of the IEC coordinate system.

[0145] If x3 < 0, the isocenter offset is in the first quadrant, then ΔX1 < 0, ΔZ1 < 0, meaning it needs to move in the negative X direction (to the left) of the IEC coordinate system and in the negative Z direction (down) of the IEC coordinate system.

[0146] Finally, based on the isocenter offsets ΔX1 and ΔZ1 in the X-axis and Z-axis directions, the coordinates of the second isocenter position O″(X0,Y1,Z0) in the X-axis and Z-axis directions are corrected to obtain the corrected position of the third isocenter as O″′(X1,Y1,Z1).

[0147] After multiple adjustments, the projection of the marker can be positioned at the center of the first detector A, and the coordinate value of O′1(x3,y3) can be almost close to (0,0), while the projection coordinate x4 of the marker on the second detector B will not change due to the correction of the isocenter.

[0148] Similarly, in the second example, such as Figure 10B As shown, the second isocenter O″ is located in the second or fourth quadrant. The first ray passes through the marker located at the second isocenter O″ to form a third image, and the second ray passes through the marker located at the second isocenter O″ to form a fourth image. The marker in the third image is located at the center of the third image, while the marker in the fourth image is not located at the center of the fourth image. In this case, according to the angle between the central ray S2O of the first ray and the Z-axis... The marker coordinate x4 is decomposed into offsets d in the X and Z axes. x4 and d z4 :

[0149]

[0150]

[0151] Then take the offset d on the second detector B x4 and d z4 The derivation to the isocenter position is based on the offset d of the marker in the X-axis and Z-axis directions. x4 and d z4 and such Figure 10BThe first and second rays shown correspond to the second imaging geometry B in the planes containing the X-axis and Z-axis directions, respectively. The isocentric offsets ΔX2 and ΔZ2 in the X-axis and Z-axis directions are determined as follows:

[0152]

[0153]

[0154] As can be seen from the above formula, the signs of ΔX2 and ΔZ2 can be determined based on the sign of x4.

[0155] If x4>0, the isocenter offset is located in the second quadrant, then ΔX2>0, ΔZ2<0, meaning it needs to move in the positive X direction (to the right) of the IEC coordinate system and in the negative Z direction (down) of the IEC coordinate system.

[0156] If x4 < 0, the isocenter offset is in the fourth quadrant, then ΔX2 < 0, ΔZ1 > 0, meaning it needs to move in the negative X direction (leftward) of the IEC coordinate system and in the positive Z direction (upward) of the IEC coordinate system.

[0157] Finally, based on the isocenter offsets ΔX2 and ΔZ2 in the X-axis and Z-axis directions, the coordinates of the second isocenter position O″(X0,Y1,Z0) in the X-axis and Z-axis directions are corrected to obtain the corrected position of the third isocenter as O″′(X2,Y1,Z2).

[0158] After several adjustments, the projection of the marker can be positioned at the center of the second detector B, and the coordinates of O′1(x4,y4) will be almost close to (0,0), while the projection coordinates x3 of the marker on the first detector A will not change due to the correction of the isocenter.

[0159] This application also provides a computer device, which includes: one or more processors; a memory; and one or more application programs, wherein the one or more application programs are stored in the memory and configured to be executed by the processor in any of the isocenter correction method embodiments described above.

[0160] This application also provides a computer device, such as... Figure 11 As shown, it illustrates a structural schematic diagram of the computer device involved in the embodiments of this application, specifically:

[0161] The computer device may include components such as a processor 1101 with one or more processing cores, a memory 1102 with one or more computer-readable storage media, a power supply 1103, and an input device 1104. Those skilled in the art will understand that... Figure 11The computer device structure shown does not constitute a limitation on the computer device and may include more or fewer components than shown, or combine certain components, or have different component arrangements. Wherein:

[0162] The processor 1101 is the control center of the computer device. It connects various parts of the computer device through various interfaces and lines. By running or executing software programs and / or modules stored in the memory 1102, and calling data stored in the memory 1102, it performs various functions of the computer device and processes data, thereby monitoring the computer device as a whole.

[0163] Optionally, processor 1101 may include one or more processing cores; preferably, processor 1101 may integrate an application processor and a modem processor, wherein the application processor mainly handles the operating system, user interface, and applications, and the modem processor mainly handles wireless communication. It is understood that the modem processor may also not be integrated into processor 1101.

[0164] The memory 1102 can be used to store software programs and modules. The processor 1101 executes various functional applications and data processing by running the software programs and modules stored in the memory 1102. The memory 1102 may mainly include a program storage area and a data storage area. The program storage area may store the operating system, application programs required for at least one function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 1102 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device. Accordingly, the memory 1102 may also include a memory controller to provide the processor 1101 with access to the memory 1102.

[0165] The computer device also includes a power supply 1103 that supplies power to the various components. Optionally, the power supply 1103 can be logically connected to the processor 1101 through a power management system, thereby enabling functions such as charging, discharging, and power consumption management through the power management system. The power supply 1103 may also include one or more DC or AC power supplies, recharging systems, power fault detection circuits, power converters or inverters, power status indicators, and other arbitrary components.

[0166] The computer device may also include an input device 1104, which can be used to receive input digital or character information and generate keyboard, mouse, joystick, optical or trackball signal inputs related to user settings and function control.

[0167] Although not shown, the computer device may also include a display device 1105, which may be a monitor, and will not be described in detail here. Specifically, in this embodiment, the processor 1101 in the computer device loads the executable files corresponding to the processes of one or more application programs into the memory 1102 according to the following instructions, and the processor 1101 runs the application programs stored in the memory 1102 to realize various functions, as follows:

[0168] Acquire a first image group, the first image group including at least two images formed by a first ray and a second ray through a marker located at a first isocenter, the central ray of the first ray and the central ray of the second ray having a preset angle; acquire the position of the marker in the first image group; correct the position of the first isocenter according to the position of the marker in the first image group.

[0169] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be performed by instructions, or by instructions controlling related hardware. These instructions can be stored in a computer-readable storage medium and loaded and executed by a processor.

[0170] Therefore, embodiments of this application provide a computer-readable storage medium, which may include: read-only memory (ROM), random access memory (RAM), a magnetic disk, or an optical disk, etc. A computer program is stored thereon, which is loaded by a processor to execute the steps in any of the isocenter correction methods provided in embodiments of this application. For example, the computer program, when loaded by a processor, can execute the following steps:

[0171] Acquire a first image group, the first image group including at least two images formed by a first ray and a second ray through a marker located at a first isocenter, the central ray of the first ray and the central ray of the second ray having a preset angle; acquire the position of the marker in the first image group; correct the position of the first isocenter according to the position of the marker in the first image group.

[0172] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the detailed descriptions of other embodiments above, which will not be repeated here.

[0173] In practice, the above structures can be implemented as independent entities or combined arbitrarily as the same or several entities. For specific implementation of the above structures, please refer to the previous method implementation examples, which will not be repeated here.

[0174] For details on the implementation of each of the above operations, please refer to the previous examples, which will not be repeated here.

[0175] The foregoing has provided a detailed description of the isocenter correction method, computer device, system, and storage medium provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for isocenter correction, characterized in that, include: Acquire a first image group, the first image group including at least two images formed by a first ray and a second ray through a marker located at a first isocenter, the central ray of the first ray and the central ray of the second ray having a preset angle; Obtain the position of the marker in the first image group; The position of the first isocenter is corrected based on the position of the marker in the first image group; The first image group includes a first image and a second image. The position of the marker in the first image group includes the coordinates of the marker in the first image in the first image coordinate system and the coordinates of the marker in the second image in the second image coordinate system. The position of the first isocenter is the coordinates of the first isocenter in the X-axis direction, Y-axis direction and Z-axis direction in the IEC coordinate system. Accordingly, the step of correcting the position of the first isocenter based on the position of the marker in the first image group includes: Based on the coordinates of the markers in the first image in the first image coordinate system and the coordinates of the markers in the second image in the second image coordinate system, the coordinates of the first isocenter in the Y-axis direction in the IEC coordinate system are corrected to obtain the position of the second isocenter. Acquire a second image set, the second image set comprising at least two images formed by the first ray and the second ray through the marker located at the second isocenter; Based on the position of the marker in the second image group, the coordinates of the second isocenter in the X-axis and Z-axis directions in the IEC coordinate system are corrected to obtain the position of the third isocenter.

2. The method according to claim 1, characterized in that, The step of correcting the Y-axis coordinates of the first isocenter position in the IEC coordinate system based on the coordinates of the markers in the first image in the first image coordinate system and the coordinates of the markers in the second image in the second image coordinate system to obtain the position of the second isocenter includes: Based on the coordinates of the marker in the first image in the first image coordinate system, and the imaging geometry of the first ray in the Y-axis direction in the IEC coordinate system, the first isocenter offset in the Y-axis direction in the IEC coordinate system is determined. Based on the coordinates of the marker in the second image in the second image coordinate system, and the imaging geometry of the second ray in the Y-axis direction of the IEC coordinate system, the second isocenter offset in the Y-axis direction of the IEC coordinate system is determined. Based on the first isocenter offset and the second isocenter offset, the coordinates of the first isocenter in the Y-axis direction of the IEC coordinate system are corrected to obtain the position of the second isocenter.

3. The method according to claim 1, characterized in that, The second image group includes a third image and a fourth image. The position of the marker in the second image group includes the coordinates of the marker in the third image in the first image coordinate system and the coordinates of the marker in the fourth image in the second image coordinate system. The step of correcting the coordinates of the second isocenter in the X-axis and Z-axis directions of the IEC coordinate system based on the position of the marker in the second image group to obtain the position of the third isocenter includes: Based on the coordinates of the marker in the first image coordinate system corresponding to the third image, the coordinates of the marker in the second image coordinate system corresponding to the fourth image, and the first imaging geometric relationship between the first ray and the second ray in the planes containing the X-axis and Z-axis directions of the IEC coordinate system, the isocenter offset in the X-axis and Z-axis directions of the IEC coordinate system is determined. Based on the isocenter offset in the X-axis and Z-axis directions of the IEC coordinate system, the coordinates of the second isocenter in the X-axis and Z-axis directions of the IEC coordinate system are corrected to obtain the position of the third isocenter.

4. The method according to claim 3, characterized in that, The step of determining the isocenter offset in the X-axis and Z-axis directions of the IEC coordinate system based on the coordinates of the marker in the first image coordinate system corresponding to the third image, the coordinates of the marker in the second image coordinate system corresponding to the fourth image, and the first imaging geometric relationship between the first ray and the second ray corresponding to the planes in the X-axis and Z-axis directions of the IEC coordinate system includes: If it is determined that the markers in the third and fourth images are not located at the center of the image, the isocenter offset in the X-axis and Z-axis directions of the IEC coordinate system is determined based on the coordinates of the markers in the first image coordinate system corresponding to the third image, the coordinates of the markers in the second image coordinate system corresponding to the fourth image, and the first imaging geometric relationship between the first ray and the second ray in the planes where the X-axis and Z-axis directions of the IEC coordinate system are located.

5. The method according to claim 4, characterized in that, If it is determined that the markers in the third image or the fourth image are all located at the center of the image, the method further includes: Based on the angle between the central ray of the target ray and the Z-axis, the coordinates of the marker in the corresponding image coordinate system are decomposed into the offsets of the marker in the X-axis and Z-axis directions in the corresponding image coordinate system, respectively. The target ray includes the first ray or the second ray. Based on the offset of the marker in the X-axis and Z-axis directions in the corresponding image coordinate system, and the second imaging geometric relationship of the first ray and the second ray corresponding to the planes in the X-axis and Z-axis directions in the IEC coordinate system, the isocenter offset in the X-axis and Z-axis directions in the IEC coordinate system is determined. Based on the isocenter offset in the X-axis and Z-axis directions of the IEC coordinate system, the coordinates of the second isocenter in the X-axis and Z-axis directions of the IEC coordinate system are corrected to obtain the position of the third isocenter.

6. A computer device, characterized in that, The computer device includes: One or more processors; Memory; and One or more applications, wherein the one or more applications are stored in the memory and configured to be executed by the processor to implement the steps in the isocenter correction method of any one of claims 1 to 5.

7. An isocenter correction system, characterized in that, The system includes: A marker is detachably fixed at the first isocenter of the radiotherapy device, the center of which coincides with the first isocenter; At least one set of imaging devices, each set of imaging devices includes an imaging source and an imager arranged opposite to each other, a first ray and a second ray emitted by the imaging source are received by the imager via the marker, and the central ray of the first ray and the central ray of the second ray have a preset angle; The computer device as described in claim 6 is connected to the imager.

8. The system according to claim 7, characterized in that, The imaging device consists of two sets, with each set emitting the first ray and the second ray respectively; or, the imaging device is rotatable, emitting the first ray and the second ray at different rotation angles.

9. A computer-readable storage medium, characterized in that, It stores a computer program, which is loaded by a processor to perform the steps in the isocenter correction method according to any one of claims 1 to 5.

Images