Effect of CT acquisition parameters of spiral CT on image quality and radiation dose

Additive Manufacturing (AM) is the most advanced manufacturing process in medical and dental industry. Computed Tomography (CT) images are the primary source to fabricate the medical models. Spiral CT scanner captures larger volume tissue in a short scan time. The major defects that appear in CT image acquisition process are Beam Hardening (BH), image noise and radiation dose. Tube voltage, tube current and pitch are the major parameters for CT image acquisition. In the present work, an attempt has been made to investigate the effect of various CT image acquisition parameters in the CT image acquisition of dry mandible phantom. A Taguchi L9 orthogonal array was used for experimental plan. The scanning defects of BH artifact and image noise were calculated by using Beam Hardening Correction Factor (BHCF) and the standard deviation of X- ray photons in the voxel respectively. Similarly radiation dose was measured with CT Dose Index volume (CTDIvolume). Grey Relational Analysis (GRA) method is used to optimize the CT image acquisition parameters, resulting increase in quality of CT images with less radiation dose. It was found that the image defects were less at optimal parameters found from GRA method compared to default image acquisition parameters.