Three-dimensional marking method for CT (Computed Tomography) image

Abstract

The invention relates to CT (Computed Tomography) image processing, in particular to a three-dimensional marking method of a CT image, which comprises the following steps of: performing image reconstruction on a CT image sequence by utilizing a multi-plane reconstruction MPR (Multi-Plane Reconstruction), and respectively displaying an axis diagram, a coronal diagram and a sagittal diagram; drawing a rectangular frame in one azimuth image of the axis diagram, the coronal diagram and the sagittal diagram, and calculating basic information of the rectangular frame; calculating an initial drawing range in the current azimuth image according to the basic information of the rectangular frame, and storing three-dimensional marking information; in the non-current azimuth image, drawing a corresponding rectangular frame according to the three-dimensional marking information; according to the technical scheme provided by the invention, the defect that accurate and efficient three-dimensional marking is difficult to perform on the CT image in the prior art can be effectively overcome.

Description

Technical Field

[0001] The present invention relates to CT image processing, and in particular to a three-dimensional annotation method for CT images. Background Art

[0002] The three-dimensional annotation of CT images mainly uses multi-planar reconstruction (MPR) technology to reprocess the stacked two-dimensional images to observe and analyze tissue structures. Multi-planar reconstruction (MPR) is a voxel-based imaging processing method that uses CT equipment to scan and obtain continuous tomographic image sequences (these image sequences contain detailed information about the human body), through which images of the coronal and sagittal planes can be reconstructed.

[0003] When using multi-planar reconstruction MPR to annotate CT image data, the main thing is to draw the region of interest in the image of any plane, and then automatically and synchronously draw the region of interest in the images of the other two planes through a set calculation formula. The adjacent regions of interest in the images of the three planes are superimposed in sequence to form a nearly three-dimensional area. This can not only help doctors understand and analyze the lesion more intuitively, but also play an important role in surgical planning and simulation, disease monitoring, treatment response evaluation and many other aspects.

[0004] The existing CT image 3D annotation is not performed on the 3D reconstructed image, but is limited to the MPR mode. The realization of the scene requires many conditions, such as: the CT image point information can be obtained and the MPR viewing can be satisfied. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the above-mentioned shortcomings of the prior art, the present invention provides a three-dimensional annotation method for CT images, which can effectively overcome the defect of the prior art that it is difficult to accurately and efficiently annotate CT images in three dimensions.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] A three-dimensional annotation method for a CT image comprises the following steps:

[0010] S1. Use multi-planar reconstruction (MPR) to reconstruct the CT image sequence and display the axial, coronal and sagittal images respectively.

[0011] S2, drawing a rectangular box in one of the axial, coronal and sagittal images, and calculating basic information of the rectangular box;

[0012] S3, calculating the initial drawing range in the current orientation image according to the basic information of the rectangular frame, and saving the 3D annotation information;

[0013] S4. In the non-current orientation image, draw a corresponding rectangular frame according to the three-dimensional annotation information.

[0014] Preferably, in S2, a rectangular frame is drawn in one of the axial image, the coronal image, and the sagittal image, and basic information of the rectangular frame is calculated, including:

[0015] S21, selecting an orientation image from the axial image, the coronal image, and the sagittal image as the current orientation image;

[0016] S22, opening a 3D annotation tool, drawing a rectangular frame in the current orientation image, and obtaining four 3D points of the rectangular frame;

[0017] S23, calculating basic information of the rectangular frame including width, height, depth and center point coordinates CenterPoint of the rectangular frame according to the four three-dimensional points of the rectangular frame;

[0018] The depth is calculated by default using the following formula:

[0019] depth = (width + height) / 2.

[0020] Preferably, in S3, according to the basic information of the rectangular frame, an initial drawing range is calculated in the current orientation image, and the three-dimensional annotation information is saved, including:

[0021] If the current orientation image is an axial image, the following formula is used to calculate the initial drawing range:

[0022] X min =CenterPoint[0]-width / 2;

[0023] X max = CenterPoint[0]+width / 2;

[0024] Y min =CenterPoint[1]-height / 2;

[0025] Y max = CenterPoint[1]+height / 2;

[0026] Z min =CenterPoint[2]-depth / 2;

[0027] Z max= CenterPoint[2]+depth / 2;

[0028] Among them, X min , X max The minimum and maximum values ​​of the X coordinates of the initial drawing range, respectively. min , Y max The minimum and maximum values ​​of the Y coordinates of the initial drawing range, respectively. min , Z max are the minimum and maximum values ​​of the Z coordinate of the initial drawing range, respectively; CenterPoint[0], CenterPoint[0], and CenterPoint[0] are the X, Y, and Z coordinates of the center point CenterPoint, respectively.

[0029] Preferably, in S4, in the non-current orientation image, drawing a corresponding rectangular frame according to the three-dimensional annotation information includes:

[0030] S41, in the non-current orientation image, calculating the camera angle NewFocalPoint and the camera position NewPosition according to the center point coordinates CenterPoint;

[0031] S42, setting the camera perspective NewFocalPoint to a new one, that is, jumping to the frame corresponding to the center point coordinate CenterPoint;

[0032] S43, calculating four 3D points in the current frame according to the 3D annotation information and the new camera perspective NewFocalPoint, and drawing corresponding rectangular frames;

[0033] If, in the current frame, there is other three-dimensional annotation information that meets the conditions within the initial drawing range, the corresponding rectangular frame is calculated and drawn together.

[0034] Preferably, the method further includes moving or scaling the rectangular frame drawn in S2:

[0035] If the rectangular box drawn in S2 is moved or scaled, S2 and S3 are repeated to update the three-dimensional annotation information, and the three-dimensional annotation information corresponding to the original rectangular box in the current orientation image is deleted;

[0036] Traverse the non-current orientation images to determine whether the current rectangular frame is within the initial drawing range;

[0037] If the current rectangular box is within the initial drawing range, four three-dimensional points are dynamically calculated according to the current rectangular box and the direction of the current rectangular box in the current orientation image, and the corresponding rectangular box is drawn.

[0038] Preferably, the method further includes performing a scrolling operation on the current orientation image or the non-current orientation image:

[0039] If the current orientation image or the non-current orientation image is scrolled, all stored three-dimensional annotation information is traversed to determine whether there is three-dimensional annotation information within the initial drawing range in the current frame after scrolling;

[0040] If there is a 3D annotation signal within the initial drawing range in the current frame after scrolling, four 3D points are dynamically calculated and the corresponding rectangular frame is drawn.

[0041] (III) Beneficial effects

[0042] Compared with the prior art, the three-dimensional annotation method of CT images provided by the present invention has the following beneficial effects:

[0043] 1) Different from the existing two-dimensional technology for annotating CT images, the present invention uses multi-planar reconstruction MPR to reconstruct the coronal and sagittal images of the CT image sequence. By drawing the region of interest in the image of any plane among the three planes, the region of interest of the corresponding size is automatically and synchronously generated in the images of the other two planes through formula calculation. At the same time, the number of rectangular frames in the images of each plane is also calculated. Only a simple drawing is performed in the image of one plane to obtain a three-dimensional cube area, so that the CT image can be accurately and efficiently annotated in three dimensions;

[0044] 2) The position or size of the region of interest can be adjusted according to the performance of the lesion in the three planes so that the lesion is covered by the region of interest. At the same time, the regions of interest in the images of other planes will also be adjusted synchronously. Finally, the regions of interest drawn in each layer are added together to obtain an approximately three-dimensional area. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0046] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] A three-dimensional annotation method for CT images, such as Figure 1 As shown in S1, multi-planar reconstruction MPR is used to reconstruct the CT image sequence, and the axial image, coronal image, and sagittal image are displayed respectively.

[0049] S2. Draw a rectangular box in one of the axial, coronal, and sagittal images, and calculate basic information of the rectangular box, including:

[0050] S21, selecting an orientation image from the axial image, the coronal image, and the sagittal image as the current orientation image;

[0051] S22, opening a 3D annotation tool, drawing a rectangular frame in the current orientation image, and obtaining four 3D points of the rectangular frame;

[0052] S23, calculating basic information of the rectangular frame including width, height, depth and center point coordinates CenterPoint of the rectangular frame according to the four three-dimensional points of the rectangular frame;

[0053] The depth is calculated by default using the following formula:

[0054] depth = (width + height) / 2.

[0055] S3. Calculate the initial drawing range in the current orientation image according to the basic information of the rectangular frame, and save the 3D annotation information, including:

[0056] If the current orientation image is an axial image, the following formula is used to calculate the initial drawing range:

[0057] X min =CenterPoint[0]-width / 2;

[0058] X max = CenterPoint[0]+width / 2;

[0059] Y min =CenterPoint[1]-height / 2;

[0060] Ymax = CenterPoint[1]+height / 2;

[0061] Z min =CenterPoint[2]-depth / 2;

[0062] Z max = CenterPoint[2]+depth / 2;

[0063] Among them, X min , X max The minimum and maximum values ​​of the X coordinates of the initial drawing range, respectively. min , Y max The minimum and maximum values ​​of the Y coordinates of the initial drawing range, respectively. min , Z max are the minimum and maximum values ​​of the Z coordinate of the initial drawing range, respectively; CenterPoint[0], CenterPoint[0], and CenterPoint[0] are the X, Y, and Z coordinates of the center point CenterPoint, respectively.

[0064] S4. In the non-current orientation image, a corresponding rectangular frame is drawn according to the three-dimensional annotation information, specifically including:

[0065] S41, in the non-current orientation image, calculating the camera angle NewFocalPoint and the camera position NewPosition according to the center point coordinates CenterPoint;

[0066] S42, setting the camera perspective NewFocalPoint to a new one, that is, jumping to the frame corresponding to the center point coordinate CenterPoint;

[0067] S43, calculating four 3D points in the current frame according to the 3D annotation information and the new camera perspective NewFocalPoint, and drawing corresponding rectangular frames;

[0068] If, in the current frame, there is other three-dimensional annotation information that meets the conditions within the initial drawing range, the corresponding rectangular frame is calculated and drawn together.

[0069] The technical solution of the present application also includes moving or scaling the rectangular frame drawn in S2:

[0070] If the rectangular box drawn in S2 is moved or scaled, S2 and S3 are repeated to update the three-dimensional annotation information, and the three-dimensional annotation information corresponding to the original rectangular box in the current orientation image is deleted;

[0071] Traverse the non-current orientation images to determine whether the current rectangular frame is within the initial drawing range;

[0072] If the current rectangular box is within the initial drawing range, four three-dimensional points are dynamically calculated according to the current rectangular box and the direction of the current rectangular box in the current orientation image, and the corresponding rectangular box is drawn.

[0073] The technical solution of the present application also includes a scrolling operation on the current orientation image or the non-current orientation image:

[0074] If the current orientation image or the non-current orientation image is scrolled, all stored three-dimensional annotation information is traversed to determine whether there is three-dimensional annotation information within the initial drawing range in the current frame after scrolling;

[0075] If there is a 3D annotation signal within the initial drawing range in the current frame after scrolling, four 3D points are dynamically calculated and the corresponding rectangular frame is drawn.

[0076] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A three-dimensional annotation method for CT images, characterized in that: The following steps are involved: S1. Use multi-planar reconstruction (MPR) to reconstruct the CT image sequence and display the axial, coronal and sagittal images respectively. S2, drawing a rectangular box in one of the axial, coronal and sagittal images, and calculating basic information of the rectangular box; S3, calculating the initial drawing range in the current orientation image according to the basic information of the rectangular frame, and saving the 3D annotation information; S4. In the non-current orientation image, draw a corresponding rectangular frame according to the three-dimensional annotation information.

2. The three-dimensional annotation method of CT images according to claim 1, characterized in that: In S2, a rectangular box is drawn in one of the axial, coronal, and sagittal images, and basic information of the rectangular box is calculated, including: S21, selecting an orientation image from the axial image, the coronal image, and the sagittal image as the current orientation image; S22, opening a 3D annotation tool, drawing a rectangular frame in the current orientation image, and obtaining four 3D points of the rectangular frame; S23, calculating basic information of the rectangular frame including width, height, depth and center point coordinates CenterPoint of the rectangular frame according to the four three-dimensional points of the rectangular frame; The depth is calculated by default using the following formula: depth = (width + height) / 2.

3. The three-dimensional annotation method of CT images according to claim 2, characterized in that: In S3, the initial drawing range is calculated in the current orientation image according to the basic information of the rectangular frame, and the 3D annotation information is saved, including: If the current orientation image is an axial image, the following formula is used to calculate the initial drawing range: X min =CenterPoint[0]-width / 2; X max =CenterPoint[0]+width / 2; Y min =CenterPoint[1]-height / 2; Y max =CenterPoint[1]+height / 2; Z min =CenterPoint[2]-depth / 2; Z max =CenterPoint[2]+depth / 2; Among them, X min , X max The minimum and maximum values ​​of the X coordinates of the initial drawing range, respectively. min , Y max The minimum and maximum values ​​of the Y coordinates of the initial drawing range, respectively. min , Z max are the minimum and maximum values ​​of the Z coordinate of the initial drawing range, respectively; CenterPoint[0], CenterPoint[0], and CenterPoint[0] are the X, Y, and Z coordinates of the center point CenterPoint, respectively.

4. The three-dimensional annotation method of CT images according to claim 1, characterized in that: In S4, in the non-current orientation image, a corresponding rectangular frame is drawn according to the three-dimensional annotation information, including: S41, in the non-current orientation image, calculating the camera angle NewFocalPoint and the camera position NewPosition according to the center point coordinates CenterPoint; S42, setting the camera perspective NewFocalPoint to a new one, that is, jumping to the frame corresponding to the center point coordinate CenterPoint; S43, calculating four 3D points in the current frame according to the 3D annotation information and the new camera perspective NewFocalPoint, and drawing corresponding rectangular frames; If, in the current frame, there is other three-dimensional annotation information that meets the conditions within the initial drawing range, the corresponding rectangular frame is calculated and drawn together.

5. The three-dimensional annotation method of CT images according to claim 1, characterized in that: It also includes moving or scaling the rectangular box drawn in S2: If the rectangular box drawn in S2 is moved or scaled, S2 and S3 are repeated to update the three-dimensional annotation information, and the three-dimensional annotation information corresponding to the original rectangular box in the current orientation image is deleted; Traverse the non-current orientation images to determine whether the current rectangular frame is within the initial drawing range; If the current rectangular box is within the initial drawing range, four three-dimensional points are dynamically calculated according to the current rectangular box and the direction of the current rectangular box in the current orientation image, and the corresponding rectangular box is drawn.

6. The three-dimensional annotation method of CT images according to claim 1, characterized in that: It also includes scrolling operations on the current orientation image or non-current orientation image: If the current orientation image or the non-current orientation image is scrolled, all stored three-dimensional annotation information is traversed to determine whether there is three-dimensional annotation information within the initial drawing range in the current frame after scrolling; If there is a 3D annotation signal within the initial drawing range in the current frame after scrolling, four 3D points are dynamically calculated and the corresponding rectangular frame is drawn.

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