Optimization of wright Huang-HYPR low dose reconstruction technique using taguchi method

Medical imaging has been identified as one of the fastest growing of all health care sectors. Despite the overwhelming benefits of computed tomography (CT) in diagnosis, there is concern over radiation induced cancer. Retaining diagnostically acceptable medical image quality with minimum radiation dose is the current need in the healthcare system. In this paper we have optimized WH-HYPR low dose image reconstruction algorithm using Taguchi method of experimental design and also studied the clinical permissible low dose range. The Wright Huang-Highly constrained back Projection (WH-HYPR) algorithm is considered as most promising low dose image reconstruction technique. This technique involves the formation of composite and weighted image whose product results in HYPR image with good temporal and spatial characteristics. Taguchi Method is a statistical approach used to fine tune the process influenting parameters more methodically and speedily [1]. Through the research work it is found that the algorithm can be optimized by considering a static constraint angle of 120° while the formation of the backprojection and also CT datasets containing around 15 to 20 time frames with least noise, maximum 20% structural and contrast variability generated a better quality HYPR image. An angle of 1° was found to be the threshold incremental angle for clinically acceptable low dose CT datasets used in WH-HYPR reconstruction. The proposed WH-HYPR algorithm allows better retention of image quality when compared with other reconstruction methods like FBP, AIDR3D and IR for undersampled data.