Statistical iteration reconstruction method of sparse-angle X-ray CT (electronic computer X-ray tomography technique) image

Abstract

The invention discloses a statistical iteration reconstruction method of a sparse-angle X-ray CT image. The method comprises the steps of obtaining the system parameters of a CT device and the projection data yraw of sparse-angle low-dose X-ray CT scanning, and performing data restoration based on mid-value prior constraints on the projection data yraw to obtain restored projection data yrestored; performing self-adaptive weighting on the projection data yraw and the restrored projection data yrestored to obtain weighted projection data yweight; performing image reconstruction on the weighted projection data yweight through a statistical iteration reconstruction method to obtain a reconstructed low-dose CT image. According to the statistical iteration reconstruction method of the sparse-angle X-ray CT image, by means of the data restoration based on the mid-value prior constraints and the self-adaptive weighting, the collected sparse low-dose CT projection data can be effectively noise-reduced, and finally high-quality reconstruction of the sparse low-dose CT image can be achieved; the reconstructed CT image can effectively eliminate plaque effects caused by noise in the reconstructed image, and the quality of the CT image can be improved significantly.

Description

Technical field [0001] The invention relates to medical image processing technology, in particular to a statistical iterative reconstruction method of sparse angle X-ray CT images. Background technique [0002] X-ray CT scans have been widely used in clinical medical imaging diagnosis, but excessive X-ray radiation doses in the process of CT scans may cause cancer. In order to reduce the damage to users, how to minimize the X-ray dosage has become one of the key technologies in the field of medical CT imaging. [0003] In order to reduce the X-ray radiation dose, the existing technology can achieve low-dose CT scanning in the following two ways: one is to reduce the tube current and scanning time during CT scanning, that is, the low mAs (milliampere-seconds) scanning method, and the other is to reduce The number of exposures within one revolution of the X-ray tube during CT scanning, that is, the sparse angle scanning mode. At present, combining the above two scanning methods, th...

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Problems solved by technology

[0005] However, the statistical iterative reconstruction methods for sparse angle scans in the prior art all default to high mAs, and do not consider the combination of sparse angle scans and low mAs

In the case of sparse angular scanning and low mAs at the same time, the TV-POCS method will be affected by a large amount of noise in the projection data in the case of low mAs, causing the reconstructed image to have a noise-induced plaque effect

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