CN114005513A

CN114005513A - MIP projection CPU algorithm

Info

Publication number: CN114005513A
Application number: CN202111246354.0A
Authority: CN
Inventors: 杨扬
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-10-26
Filing date: 2021-10-26
Publication date: 2022-02-01

Abstract

The invention relates to the technical field of medical image processing, and particularly provides a MIP projection CPU algorithm, which comprises the following steps: s1, taking out the images in the DICOM file in sequence and forming a three-dimensional stack; s2, converting the interval unit from millimeter to pixel to form a pixel cube; s3, taking the center of the pixel cube as the sphere center to form a sphere, and taking any point on the surface of the sphere as an observation point; s4, performing ray projection on the observation point, and projecting the point with the maximum density, which penetrates through the pixel cube, of the initial ray on a ray vertical plane; s5, making parallel rays of the initial rays until all the parallel rays passing through the pixel cube are projected; s6, forming an initial image; s7, rotating and zooming the points of the initial image to form a positive direction image; s8, rearranging and interpolating pixel points in the positive direction image to obtain a projected image; s9, the projection image is displayed on the interface, and imaging can be performed completely according to the definition of MIP and more accurate display result can be obtained by using only CPU resources.

Description

MIP projection CPU algorithm

Technical Field

The invention relates to the technical field of medical image processing, in particular to a MIP projection CPU algorithm.

Background

DICOM image three-dimensional visualization is the study of two-dimensional image sequences acquired by various medical imaging devices to construct three-dimensional geometric models of tissues or organs, and "true" rendering and reality on computer screens. Currently, there are two main categories of DICOM image three-dimensional visualization methods: one type describes the three-dimensional structure of an object by splicing and fitting the surface of the object through geometric units, is called a surface drawing method, and is realized by computer graphics technology and hardware based on one-dimensional image edge or contour line extraction. The image formed by the algorithm has high resolution and high generation speed, and can rotate and change the illumination effect quickly and flexibly. It is suitable for drawing tissue and organ with clear surface characteristics. Another type is a method of projecting voxels directly to a display plane, called a volume rendering method. The algorithm does not require accurate segmentation, but directly applies the visual principle, and finally obtains an image with a three-dimensional semitransparent effect through volume data resampling and voxel gray value processing. Volume rendering methods typically do not require precise segmentation of the displayed object, but rather process each voxel in the volumetric data field separately. Therefore, when three-dimensional display is performed on tissues and organs with fuzzy shape features, a volume rendering method is suitable, but because the calculation amount of the algorithm is too large, the requirement of interactive operation in practical application cannot be met even if a high-performance computer is used, and therefore surface rendering is still the current mainstream algorithm.

In the existing medical imaging three-dimensional technology, each layer of picture in DCM generated by DICOM is projected to form a model with the maximum density of each point through MIP and displayed on a plane graph, most of the solutions are to generate a three-dimensional model first and then project the three-dimensional model onto the plane, such a method needs pretreatment and is not completely consistent with the definition of MIP, and most of the solutions are to use a display card to simulate, calculate and image, so that many common computers cannot meet the operation requirements of the users, a method is needed at present, so that the common computers can operate medical three-dimensional imaging, namely, the MIP method can be realized under the condition of only utilizing CPU resources.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: in order to solve the problem of low utilization rate of CPU resources in the traditional medical imaging three-dimensional technology, the invention provides a MIP projection CPU algorithm to solve the problem.

The technical scheme adopted by the invention for solving the technical problems is as follows: a MIP projection CPU algorithm comprising the steps of: s1, taking out all the images in the DICOM file in sequence, and forming a three-dimensional stack from top to bottom at certain intervals by the taken-out images;

s2, converting the interval unit from millimeter to pixel according to proportion, and interpolating and filling the pixel to form a pixel cube;

s3, taking the center of the pixel cube in S2 as the sphere center to form a sphere, taking any point of the surface of the sphere as an observation point, and taking the surface of the sphere as an observation point surface;

s4, performing ray projection on the observation points, and projecting the points with the maximum density, which penetrate through the pixel cube, of the initial rays on a ray vertical plane relative to the vertex position;

s5, making parallel rays of the initial rays, and projecting the points, with the maximum density, of the parallel rays passing through the pixel cube on a ray vertical plane in the S4 until all the parallel rays passing through the pixel cube are projected;

s6, forming an initial image after the parallel rays are projected;

s7, rotating and zooming points on the initial image to enable the initial image to be a positive direction image;

s8, rearranging and interpolating pixel points in the forward direction image to obtain a projected image;

and S9, displaying the projection image in the S8 in an interface.

Preferably, the method further comprises the following steps: and S10, moving the observation point along the surface of the observation point, and then repeating the steps S4-S9 to obtain projection images in different directions.

Preferably, in S6, the plane X-axis and Y-axis directions of the initial image are determined according to the right-hand rule.

Preferably, in S7, the size of the forward direction image is adjusted according to the scaling of the initial image.

Preferably, in S8, the pixels are rearranged and interpolated, and then image smoothing processing is performed.

Preferably, in S3, the sphere has a radius twice the length of the edge of the pixel cube.

The invention has the advantages that large-scale 3D dot matrix calculation is not needed, the requirement on the performance of the display card is reduced, imaging can be completely carried out according to the definition of MIP by using CPU resources, and a more accurate display result is obtained.

Drawings

The invention is further illustrated with reference to the following figures and examples.

FIG. 1 is an algorithm flow chart of a preferred embodiment of the MIP projection CPU algorithm of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", and the like, indicate orientations and positional relationships based on the orientations and positional relationships shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be considered as limiting the present invention.

Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "connected" and "connected" are to be interpreted broadly, e.g., as being fixed or detachable or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

As shown in fig. 1, the present invention provides an embodiment of a MIP projection CPU algorithm, which includes the following steps: s1, taking out all the images in the DICOM file in sequence, and forming a three-dimensional stack from top to bottom at certain intervals by the taken-out images;

s3, taking twice of the edge length of the pixel cube in S2 as a radius, taking the center of the pixel cube as a sphere center to form a sphere, taking any point of the surface of the sphere as an observation point, and taking the surface of the sphere as an observation point surface;

s4, performing ray projection on the observation point, and projecting the point with the maximum density of the initial ray passing through the pixel cube on a ray vertical plane relative to the vertex position, wherein the point with the maximum density is the point with the maximum tissue density in anatomy, and can also be understood as the point with the maximum gray level in imaging;

s6, forming an initial image after the projection of the parallel rays is finished, and determining the plane X-axis direction and the plane Y-axis direction of the initial image according to the right-hand rule, for example, the right hand is back to the screen, the thumb points to the positive direction of the X-axis, the index finger points to the positive direction of the Y-axis, and the middle finger points to the positive direction of the Z-axis;

s7, rotating and zooming the points on the initial image to make the initial image adjusted into a positive direction image with a required size according to the zooming proportion;

s8, rearranging and interpolating pixel points in the positive direction image, and performing image smoothing to obtain a projected image, so that each pixel point in the positive direction image is well processed;

s9, displaying the projected image in S8 in the interface, for example, displaying the projected image in the interface including but not limited to: the interface of the equipment such as a mobile phone, a tablet or a computer.

S10, moving the observation point along the surface of the observation point, and then repeating the steps of S4-S9 to obtain projection images in different directions.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, a schematic representation of the term does not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims

1. An MIP projection CPU algorithm, characterized by comprising the steps of: s1, taking out all the images in the DICOM file in sequence, and forming a three-dimensional stack from top to bottom at certain intervals by the taken-out images;

s6, forming an initial image after the parallel rays are projected;

and S9, displaying the projection image in the S8 in an interface.

2. The MIP projection CPU algorithm of claim 1, further comprising: and S10, moving the observation point along the surface of the observation point, and then repeating the steps S4-S9 to obtain projection images in different directions.

3. A MIP projection CPU algorithm according to claim 2, wherein: in S6, the planar X-axis and Y-axis directions of the initial image are determined according to the right-hand rule.

4. A MIP projection CPU algorithm according to claim 3, wherein: in S7, the size of the forward direction image is adjusted according to the scaling of the initial image.

5. The MIP projection CPU algorithm of claim 4 wherein: in S8, the pixels are rearranged and interpolated, and then image smoothing processing is performed.

6. The MIP projection CPU algorithm of claim 5, wherein: in S3, the sphere is at a radius of twice the edge length of the pixel cube.