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 can be used for confirming relative positions among an X ray source focus, a turntable rotating center and the CT detector in CT; 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 application, 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 the difference in the absorption and transmittance of X-rays by different objects, an X-ray source is used to emit X-rays to penetrate Then, the X-ray intensity after penetrating the object is detected by a detector with extremely high sensitivity, and the obtained intensity data is processed 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 an...

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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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