Image enhancement for computed tomography using directional interpolation for sparsely-sampled sinogram

This paper presents an image enhancement for computed tomography (CT) using a directional sparsely-sampled sinogram interpolation. In CT scanning, radiation exposure to human tissues needs to be minimized. Naturally reducing radiation dose has been discussed in various approaches. Among them, a sparsely-sampled sinogram is an effective approach to minimize radiation dose itself in CT scanning. However, less radiation in CT scanning provide a poor image quality since reconstructed images suffer from the streak artifact due to lack of X-ray views. To reduce the streak artifact, an efficient sinogram interpolation method needs to be studied. In this paper, to enhance image quality, we propose a novel sinogram interpolation based on directional information. To do this, a directional interpolation from deinterlacing is introduced and applied to sinogram interpolation efficiently. To evaluate the proposed method, experiments with a simulated phantom and clinical CT images are carried out. The results indicate that the proposed sinogram interpolation method outperforms the existing interpolation methods in terms of image quality. (C) 2018 Elsevier GmbH. All rights reserved.