Cone beam CT metal artifact correction algorithm based on priori image

Abstract

The invention provides a cone beam CT metal artifact correction algorithm based on a prior image, and the algorithm introduces bilateral filtering to preprocess an original reconstructed image, can remove noise, and reserves image edge information. Constructing a model by adopting the projection data of the prior image and the metal neighborhood projection data; the method is used for carrying outinterpolation restoration on a metal projection area, eliminating metal artifacts and inhibiting generation of secondary artifacts, and comprises the following steps: firstly, carrying out preprocessing such as bilateral filtering, metal threshold segmentation and tissue clustering on a reconstructed image containing the metal artifacts to obtain a metal image and a priori image; performing forward projection on the metal image and the prior image to obtain a metal projection area and prior projection data; then repairing the metal projection area to obtain repaired projection data; and finally, reconstructing the restored projection data by using an analytic reconstruction algorithm to obtain an intermediate reconstructed image, and fusing the intermediate reconstructed image with the metal image segmented in the first step to obtain a final corrected image.

Description

technical field [0001] The invention belongs to the field of medical image processing, and relates to a prior image-based cone beam CT metal artifact correction algorithm, which can be used for cone beam CT imaging systems to effectively suppress artifacts caused by metal implants during reconstruction. Background technique [0002] Cone-beam computed tomography (CBCT) is widely used in stomatology and orthopedics because of its small size, low radiation dose, and high isotropic spatial resolution. It is currently the most promising and practical method. One of the imaging methods. However, metal implants (such as metal dentures, bone nails, etc.) carried in the patient's body will bring serious strip artifacts to the reconstructed image—metal artifacts, which greatly affect the diagnostic accuracy. Metal Artifacts Reduction (MAR) algorithm can reduce or even eliminate streak artifacts during image reconstruction and improve the quality of reconstructed images. [0003] At...

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Problems solved by technology

[0006] In view of the problems of secondary artifacts and edge blurring in the image corrected by the existing interpolation-like MAR algorithm, this patent proposes a prior image-based cone beam CT metal artifact correction algorithm (Prior-image-based MAR, PIB- MAR)

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