Correction Of Cupping Artifacts in Axial and cross-sectional Cone Beam Computed Tomography images By Using İmage Processing algoritms, In Matlab Software

Abstract

Objectives: The aim of this study was to present an algorithm to eliminate cupping artifacts from axial and other reconstructed CBCT images. Materials and methods: In this paper, we used CBCT images of NewTom VG imaging system, in which every image has a resolution of 366×320 in DICOM format. Fifty images of patients with cupping artifacts were selected. Using Sobel edge detector and nonlinear gamma correction coefficient, the difference was calculated between the density of axial images in the main image and the image resulting from nonlinear gamma correction at the exact location of the radiopaque dental materials detected by Sobel. At points in which this density difference was out of a definite limit, the points were treated as image artifacts and were eliminated from the main image by inpainting method. Results: The resultant axial images, for producing reconstructed craoss-sectional, panoramic images without cupping artifacts, were imported into NNT viewer V5.6 and utilized. Conclusions: With comparison acquired images, observed that the offering algorithm is practical and effective for reducing the cupping artifacts and preserving the quality of the reconstructed images. This algorithm doesn’t need to any additional equipment.