Method and system for eliminating geometrical artifacts in CT (Computerized Tomography) image

Abstract

The invention relates to a method and system for eliminating geometrical artifacts in a CT (Computerized Tomography) image. The method comprises the following steps of: performing CT scanning on a die body to obtain the projection coordinate of the mass center of the die body on a CT detector; defining geometrical parameters according to the projection coordinate of the mass center of the die body on the CT detector, and substituting the geometrical parameters in a reconstruction formula, wherein the geometrical parameters include: a distance h of a projection point of the turntable rotating center on the detector and a center of the detector, an included angle alpha between an ideal position of a straight line where the detector id and an actual position, and a distance SDD between the projection point of the turntable rotating center on the detector and an X ray source focus; performing CT scanning on an object to be imaged to obtain fan-beam projection parameters of the object to be imaged; and processing the fan-beam projection parameters of the object to be processed by the reconstruction formula to obtain CT image data of the object to be imaged and further obtain a CT image with the CT image data of the object to be imaged serving as a gray level. According to the technical scheme, the method and the system can be used for accurately obtaining the CT image without the geometrical artifacts.

Description

technical field [0001] The invention relates to the field of CT applications, in particular to a method and system for eliminating geometric artifacts in CT images. Background technique [0002] CT (X-ray computed tomography, computed tomography) is an important non-destructive testing technology. Its working principle is: using different objects to absorb and transmit X-rays differently, using X-ray sources to emit X-rays to penetrate object, and then use a highly sensitive detector to detect the X-ray intensity after penetrating the object, and process the acquired intensity data by the processing device to obtain a cross-sectional or three-dimensional image of the object. By observing the image, you can Learn about the internal structure of objects. In the medical field, by using CT to detect the human body, a cross-sectional or three-dimensional image of the inspected part of the human body can be obtained, and then small lesions in any part of the body can be found. ...

AI Technical Summary

Problems solved by technology

However, it is difficult for the actual CT to meet the above conditions. The resulting geometric parameter error leads to geometric artifacts in the image obtained by CT, which greatly reduces the resolution of the CT image and affects the correct interpretation of the CT image. affect the judgment of the disease

[0004] The existing technology is to manually adjust some components in the CT, relying on the subjective judgment of the CT image quality to eliminate the geometric artifacts in the CT image, this correction method is relatively rough, mainly relying on the experience of the adjustment personnel to judge the correction Therefore, the calibration quality is not guaranteed, and the error may increase due to adjustment errors and cannot be recovered.

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