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.