Rapid establishment method of voxel model for radiation protection

Abstract

The invention mainly provides a method for quickly establishing a voxel model for radiation protection. The method comprises the following steps: S1, acquiring image parameters of a simulation physical model; s2, realizing gray scale display of the image; s3, carrying out structure segmentation adjustment on the image; and S4, constructing a voxel data set, and establishing a voxel model. Through the method, the establishment time of the voxel model can be shortened to several hours from several months of a traditional method, and the voxel model established by the method can meet simple dose calculation requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of radiation dose, and particularly to a method for quickly establishing a voxel model for radiation protection. Background Art

[0002] In the field of radiation protection, the human body computational model is an essential basic research tool. It plays an important role in both external irradiation and internal irradiation dose assessment. The current main methods for establishing a human body digital model are to obtain tomographic image data of the human body through CT scanning, MRI scanning or cutting of cadavers, distinguish different tissues by manually dividing the organ contours, and voxelize the tomographic image data of the human body to obtain a human body voxel model. The time required for manually dividing the organ contours in this method is relatively long, usually several weeks to several months. A more convenient method is needed to quickly establish a voxel model.

[0003] The above problems need to be solved urgently. Summary of the Invention

[0004] The present invention discloses a method for quickly establishing a voxel model for radiation protection, aiming to solve the technical problems existing in the prior art.

[0005] The present invention adopts the following technical solutions:

[0006] A method for quickly establishing a voxel model for radiation protection includes the following steps:

[0007] S1. Obtain the image parameters of the simulation physical model;

[0008] S2. Realize the gray-scale display of the image;

[0009] S3. Adjust the structural segmentation of the image;

[0010] S4. Construct a voxel data set and establish a voxel model.

[0011] In one embodiment, the step S1 includes: performing three-dimensional scanning on the simulation physical model to obtain a CT scan image, and obtaining the image parameters of the simulation physical model through DICOM image reading software.

[0012] In one embodiment, the image parameters include: the number of pixel points is 512×512, the size represented by a unit pixel point is 1.171875×1.171875 mm, and the slice thickness is 5 mm.

[0013] In one embodiment, step S2 includes: importing the image parameters in step S1 into the DICOM image reading software, setting the lower left corner of the CT image as the origin, with a voxel size of 1.171875×1.171875×5 mm, calculating the three-dimensional spatial coordinates of each voxel coordinate position, and obtaining the three-dimensional spatial coordinates of each voxel.

[0014] In one embodiment, step S2 further includes: preprocessing the voxel data, denoising, removing or repairing the CT values in the CT photos; normalizing, normalizing the removed or repaired CT values to 0-1, and performing equal-proportion reduction; interpolation, refining the voxel size of 1.171875×1.171875×5 mm to 1.171875×1.171875×2.5 mm to improve the resolution.

[0015] In one embodiment, step S2 further includes: defining a transfer function to map the CT values of the voxel data to optical properties to highlight specific tissues or structures.

[0016] In one embodiment, step S3 includes: determining that the CT value of the hard bone in the CT image is 700-2000 HU, adjusting the CT value range to completely select the hard bone structure, and marking all the voxel points of the hard bone.

[0017] In one embodiment, step S3 further includes: adjusting the CT value range to completely select the external air and marking all the voxel points of the external air; adjusting the CT value range to completely select the soft tissue and marking all the voxel points of the soft tissue; adjusting the CT value range to completely select the lung tissue and marking all the voxel points of the lung tissue.

[0018] In one embodiment, step S4 includes: screening the voxel points of the hard bone structure, external air, soft tissue, and lung tissue, traversing the CT three-dimensional voxel data, determining whether each voxel point belongs to the target area, and for the voxel points with CT values within the specified range, marking them as selected voxels and recording the spatial coordinates, corresponding CT values, and spatial resolution information of each selected voxel.

[0019] In one embodiment, step S4 further includes: organizing all the selected voxels into a three-dimensional lattice structure, constructing a voxel data set, and establishing a voxel model.

[0020] The technical solution adopted by the present invention can achieve the following beneficial effects:

[0021] The present invention mainly provides a method for quickly establishing a voxel model for radiation protection, including the following steps: S1, obtaining the image parameters of the simulation physical model; S2, realizing the gray display of the image; S3, performing structural segmentation and adjustment on the image; S4, constructing a voxel data set and establishing a voxel model. By this method, the establishment process and the required time of the human voxel model can be simplified, and the establishment time of the voxel model can be shortened from several months of the traditional method to several hours, thereby improving the working efficiency of the human dose simulation calculation process. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments, which form a part of the present invention. The schematic embodiments of the present invention and their descriptions explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0023] Figure 1 It is a schematic diagram of the method for quickly establishing a voxel model for radiation protection provided by an embodiment of the present invention;

[0024] Figure 2 It is a three-dimensional scanned CT image provided by an embodiment of the present invention;

[0025] Figure 3 It is a CT image with too small CT range value in the hard bone CT image provided by an embodiment of the present invention;

[0026] Figure 4 It is a CT image with too large CT range value in the hard bone CT image provided by an embodiment of the present invention;

[0027] Figure 5 It is an adjusted hard bone CT image provided by an embodiment of the present invention;

[0028] Figure 6 It is a schematic diagram of the overall structure of the voxel model provided by an embodiment of the present invention;

[0029] Figure 7 It is a schematic diagram of the bone structure of the voxel model provided by an embodiment of the present invention. Detailed Embodiments

[0030] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions of the present invention in conjunction with the specific embodiments and corresponding drawings of the present invention. In the description of the present invention, it should be noted that the term "or" is usually used in the sense of including "and / or" unless otherwise clearly specified in the content.

[0031] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or a magnetic connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations. In addition, in the description of the present application, the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, or more, unless otherwise specifically defined.

[0032] Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0033] To solve the problems existing in the prior art, an embodiment of the present application provides a method for quickly establishing a voxel model for radiation protection.

[0034] Figure 1 Schematic diagram of a method for quickly establishing a voxel model for radiation protection provided by an embodiment of the present invention; as Figure 1 shown, a method for quickly establishing a voxel model for radiation protection includes the following steps:

[0035] S1. Obtain the image parameters of the simulation physical model; S2. Realize the gray-scale display of the image; S3. Adjust the structural segmentation of the image; S4. Construct a voxel data set and establish a voxel model. By this method, the establishment process and the required time of the human voxel model can be simplified, and the establishment time of the voxel model can be shortened from several months by the traditional method to several hours, thereby improving the working efficiency of the human dose simulation calculation process.

[0036] In one embodiment, step S1 includes: performing three-dimensional scanning on the simulation physical model to obtain a CT scan image, and obtaining the image parameters of the simulation physical model through DICOM image reading software. Figure 2 Three-dimensional scanned CT image provided by an embodiment of the present invention, as Figure 2 shown, obtaining the image parameters of the CT scan of the simulation physical model through DICOM image reading software.

[0037] In one embodiment, the image parameters include: the number of pixel points is 512×512, the size represented by a unit pixel point is 1.171875×1.171875mm, and the slice thickness is 5mm.

[0038] In one embodiment, step S2 includes: importing the image parameters in step S1 into the DICOM image reading software, setting the lower left corner of the CT image as the origin, with a voxel size of 1.171875×1.171875×5 mm, calculating the three-dimensional spatial coordinates of each voxel position, and achieving grayscale display of the image through direct volume rendering (DVR) technology.

[0039] In one embodiment, step S2 further includes: preprocessing the voxel data, and the preprocessing specifically includes: denoising, removing or repairing the CT values in the CT photos; normalizing, normalizing the removed or repaired CT values to 0-1, and reducing the CT values in equal proportion; interpolating, refining the voxel size of 1.171875×1.171875×5 mm to 1.171875×1.171875×2.5 mm to improve the resolution.

[0040] Preferably, the CT value of bone is usually 300-2000 HU, the CT value of hard bone is usually 700-2000 HU, the CT value of the lung is usually -600 to -900, the CT value of soft tissue is usually -100 to 100, the CT value of bone is usually 400-1000, and the CT value of external air is usually -1000. The denoising specifically means removing or repairing the CT values in the CT photos that exceed or are lower than the normal CT values of specific tissues. For example, the CT value of bone is usually 300-2000 HU, and the denoising specifically removes the CT values in the CT photos that are lower than 300 HU and higher than 2000 HU.

[0041] Preferably, normalization can cancel the order-of-magnitude differences between the data of each dimension, and avoid excessive prediction errors caused by large order-of-magnitude differences between the input and output data.

[0042] In one embodiment, step S2 further includes: defining a transfer function to map the CT values of the voxel data to optical properties to highlight specific tissues or structures.

[0043] Preferably, the transfer function refers to the ratio of the Laplace transform (or z-transform) of the response (i.e., output) of a linear system under zero initial conditions to the Laplace transform of the excitation (i.e., input). It is denoted as G(s) = Y(s) / U(s), where Y(s) and U(s) are the Laplace transforms of the output and input respectively. Through the transfer function, the CT values of the voxel data are mapped to optical properties to highlight specific tissues or structures. For example, specific tissues or structures can be highlighted according to color and opacity.

[0044] The quality of voxel data is optimized by denoising, normalizing, interpolating, etc. the voxel data, reducing the influence of noise on the rendering result.

[0045] In one embodiment, step S3 includes: determining that the CT value of hard bone in the CT image is 700 - 2000 HU, adjusting the CT value range to completely select the hard bone structure, and marking all voxel points of the hard bone.

[0046] Taking hard bone as an example, first determine that the CT value of hard bone in the CT image is usually 700 - 2000 HU, and completely select the hard bone structure by adjusting the CT value range. Figure 2 A CT image with too small CT range value in the hard bone CT image provided by an embodiment of the present invention; Figure 3 A CT image with too large CT range value in the hard bone CT image provided by an embodiment of the present invention;

[0047] Figure 3 An adjusted hard bone CT image provided by an embodiment of the present invention. After adjustment, all voxel points of the hard bone are marked as 4.

[0048] In one embodiment, step S3 further includes: adjusting the CT value range to completely select the external air, and marking all voxel points of the external air; adjusting the CT value range to completely select the soft tissue, and marking all voxel points of the soft tissue; adjusting the CT value range to completely select the lung tissue, and marking all voxel points of the lung tissue.

[0049] Specifically, all voxel points of the external air are marked as 1, the soft tissue is marked as 2, and the lung tissue is marked as 3.

[0050] In one embodiment, step S4 includes: screening the voxel points of the hard bone structure, external air, soft tissue, and lung tissue, traversing the CT three-dimensional voxel data, judging whether each voxel point belongs to the target area, for the voxel points with CT values within the specified range, marking them as selected voxels, and recording the spatial coordinates, corresponding CT values, and spatial resolution information of each said selected voxel.

[0051] Specifically, screening is carried out in sequence, judging whether each voxel belongs to the target area, if the CT value is within the specified range, it means it meets the requirements, marking it as a selected voxel, for each selected voxel, recording its spatial coordinates (x, y, z) and the corresponding CT value, in addition, retaining the spatial resolution information of the voxel (such as voxel size, slice spacing) to ensure the geometric accuracy of the model.

[0052] Figure 4 A schematic diagram of the overall structure of the voxel model provided by an embodiment of the present invention; Figure 5 A schematic diagram of the bone structure of the voxel model provided by an embodiment of the present invention. AsFigure 4-5 As shown, all selected voxels are organized into a three-dimensional lattice structure, a voxel data set is constructed, and a voxel model is established.

[0053] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the spirit of the present invention and the scope protected by the claims, and all of them fall within the protection scope of the present invention.

Claims

1. A method for rapidly establishing a voxel model for radiation protection, characterized in that: The steps include: S1, obtaining image parameters of the simulated physical model; S2, realize grayscale display of image; S3, performing structural segmentation and adjustment on the image; S4. Construct a voxel data set and establish a voxel model.

2. The method for rapidly establishing a voxel model for radiation protection according to claim 1, characterized in that: The step S1 includes: performing a three-dimensional scan on the simulated physical model, obtaining a CT scan image, and obtaining image parameters of the simulated physical model through DICOM image reading software.

3. The method for rapidly establishing a voxel model for radiation protection according to claim 2, characterized in that: The image parameters include: the number of pixels is 512×512, the unit pixel represents a size of 1.171875×1.171875 mm, and the slice thickness is 5 mm.

4. The method for rapidly establishing a voxel model for radiation protection according to claim 1, characterized in that: The step S2 includes: importing the image parameters in step S1 into the DICOM image reading software, setting the lower left corner of the CT image as the origin, the voxel size as 1.171875×1.171875×5 mm, calculating the coordinate position of each voxel, and obtaining the three-dimensional space coordinates of each voxel.

5. The method for rapidly establishing a voxel model for radiation protection according to claim 4, characterized in that: The step S2 further includes: preprocessing the voxel data, Denoising: removing or repairing the CT values ​​in CT images; Normalization: normalize the CT values ​​after removal or restoration to 0-1 and reduce them proportionally; Interpolation was performed to refine the voxel size of 1.171875 × 1.171875 × 5 mm to 1.171875 × 1.171875 × 2.5 mm to improve the resolution.

6. The method for rapidly establishing a voxel model for radiation protection according to claim 5, characterized in that: The step S2 further includes: defining a transfer function to map the CT value of the voxel data into an optical property to highlight a specific tissue or structure.

7. The method for rapidly establishing a voxel model for radiation protection according to claim 1, characterized in that: The step S3 includes: determining that the CT value of the hard bone in the CT image is 700-2000HU, adjusting the CT value range to completely select the hard bone structure, and marking all voxel points of the hard bone.

8. The method for rapidly establishing a voxel model for radiation protection according to claim 7, characterized in that: The step S3 also includes: adjusting the CT value range to completely select the external air and marking all voxel points of the external air; adjusting the CT value range to completely select the soft tissue and marking all voxel points of the soft tissue; adjusting the CT value range to completely select the lung tissue and marking all voxel points of the lung tissue.

9. The method for rapidly establishing a voxel model for radiation protection according to claim 8, characterized in that: The step S4 includes: screening the voxel points of hard bone structure, external air, soft tissue, and lung tissue, traversing the CT three-dimensional voxel data, judging whether each voxel point belongs to the target area, marking the voxel points whose CT values ​​are within the specified range as selected voxels, and recording the spatial coordinates, corresponding CT values, and spatial resolution information of each selected voxel.

10. The method for rapidly establishing a voxel model for radiation protection according to claim 9, characterized in that: The step S4 also includes: organizing all the selected voxels into a three-dimensional lattice structure, constructing a voxel data set, and establishing a voxel model.

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