Evaluation of reconstructed images on the micro-CT system using total variation minimization

The quantitative evaluation is required in micro-CT imaging with total variation (TV) minimization method at few-view scan. We acquired the phantom and mouse image using the micro-CT system (DRGem, Harmony 80H, Republic of Korea) and demonstrated the contrast, noise, and similarity of the images. To verify the contrast-to-noise ratio (CNR), sparse data were obtained using phantom and mouse and filtered-backprojection (FBP) images of phantom and mouse data were used as a reference image reconstructed with 400 projection data. Universal quality index (UQI) was used as an image similarity metric for comparison between TV minimization algorithm and FBP algorithm for both the phantom and the mouse image. CNR values for the image derived from TV minimization algorithm with 80-view was approximately 45 % higher than FBP with 400-view up to 10 % iodine solution material. UQI values for the phantom and the mouse image were measured with 0.974 and 0.999, respectively. TV minimization algorithm was proved to be advantageous for micro-CT system. Contrast and noise properties on image from TV minimization at few-view were higher than FBP 80-view and full-view scan. However, CNR from 15 % iodine solution to 20 % iodine solution were lower than FBP due to the lower-intensity of the X-rays. The reconstructed images for both phantom and mouse from TV minimization algorithm were well matched to FBP-reference images.