Bunched sparse-view CT using a moving multi-slit collimator

In computed tomography (CT), useful anatomical information can be obtained and used for various clinical purposes. However, reduction of radiation dose is one of the important issues. The aim of our work is to decrease radiation dose using an oscillating multi-slit collimator while preserving image quality. The collimator was set to mask data perpendicular to the rotation axis, and it was driven to oscillate parallel to the rotation axis. The oscillating motion was programmed to have a sinusoidal motion. Varying sizes of slit-openings were simulated in this work: half, one-fourth, and one-eighth openings. We used a total variation (TV) minimization algorithm to reconstruct the images from these bunched sparse-view data. Universal quality Index (UQI) was calculated to compare the image similarities to the reference image. This work successfully demonstrated a feasibility of the proposed method for low-dose CT. This method may be implemented in the existing CT systems without much technical difficulties.