Metal artifact correcting method and device for CT image

Abstract

The invention provides a metal artifact correcting method and device for a CT image. Through restraint of a prior projection, Gaussian energy decrease treatment is performed on metal zone iteration of an original projection according to the original projection and a metal projection, and a preliminary uncorrected projection meeting conditions is obtained and a preliminary corrected image is obtained through back projection reconstruction. Smooth denoising is performed on the preliminary corrected image and then the preliminary corrected image is used for updating a prior image. Through iteration update of the prior image and obtaining updated prior image through performing projection on the prior image subjected to each process of update, with the constraint of the updated prior projection, the preliminary uncorrected project meeting conditions is obtained and the preliminary corrected image is obtained further. The preliminary corrected image meeting conditions is obtained and is fused with a metal image, and a final corrected image is obtained. The invention realizes metal artifact correction of the CT image effectively and avoids problems of insufficient smoothness of interpolation boundary of an interpolation method and long correcting time of an iteration method in the prior art.

Description

technical field [0001] The present invention relates to the field of image processing, and more specifically, to a method and device for correcting metal artifacts in CT images. Background technique [0002] X-ray computed tomography (Computed Tomography, CT) is a very important medical imaging method and industrial non-destructive testing technology, which is widely used in the medical field. When acquiring a CT image of a patient, when the X-ray emitted by the detector passes through the part of the human body where there is a metal object, the ratio of low-energy X-ray photons absorbed by the metal object is much higher than that of high-energy X-ray photons. Therefore, most of the X-ray photons received by the detector are high-energy X-ray photons, so that the average energy spectrum of X-rays will shift to the direction of the high-energy spectrum, resulting in serious metal artifacts in the CT image reconstructed by back projection. These artifacts seriously affect t...

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Problems solved by technology

[0004] The present invention provides a method and device for correcting metal artifacts in CT images to solve the problem of unsmooth interpolation boundary of the interpolation method and the long correction time of the iterative method in the prior art

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