CT scanner, defocusing intensity measurement method of CT scanner and defocusing correction method of CT scanner

Abstract

The invention relates to a CT scanner, a defocusing intensity measurement method of the CT scanner and a defocusing correction method of the CT scanner, and aims to provide an actual defocusing intensity measurement method and a defocusing correction method based on the actual defocusing intensity measurement method. The defocusing intensity measurement method includes the steps that a die body which can shield X-rays is placed in an aperture of a rack of the scanner; X-ray bulb tubes and a detector array of the scanner rotate around the rotating center of the rack of the scanner to execute rotating exposure scanning, and radiation intensity of the X-rays received by detectors can be accordingly weakened or enhanced due to the fact that the die body shields or retreats from the X-ray bulb tubes in every rotating circle; radiation intensity values are acquired from at least a part of the detectors at the preset sampling rate; eventually, defocusing intensity of the X-ray bulb tubes at the corresponding positions is calculated respectively according to the change of radiation intensity values of the detectors of adjacent sampling points when the die body gradually shields or retreats from the X-ray maximum radiation area of at least the part of the detectors, and then distribution of the defocusing intensity of the X-ray bulb tubes is acquired.

Description

technical field [0001] The invention relates to an electronic computer X-ray tomography scanner (abbreviated as a CT scanner), in particular to a method for measuring defocus intensity and a method for correcting defocus of the CT scanner. Background technique [0002] A CT scanner is a device that uses computer technology to reconstruct a tomographic image of a measured object to obtain a three-dimensional tomographic image. CT scanners use X-ray tubes to emit X-rays to the focal area, thereby focusing on the irradiated object (such as human organs). Defocus radiation is a phenomenon in which X-rays are radiated from areas other than the focus in the X-ray tube. It is caused by secondary electrons and field emission electrons bombarding areas other than the focus of the tube target area to generate X-rays. The defocusing phenomenon will lead to degradation of contrast or shadows at the edge of the illuminated object, affecting or even misleading doctors to make a diagnosis...

AI Technical Summary

Problems solved by technology

The disadvantage of the theoretical model calculation is that it may differ from the defocused radiation of the actual product, resulting in an inaccurate calculated defocus correction factor

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