Preliminary investigation of dose allocation in low-dose cone-beam CT

Current cone-beam CT imaging requires dense angular sampling that is imposed by the FDK-type image-reconstruction algorithm. In an attempt to investigate the possibility of low-dose CBCT by reducing the number of projection views, we applied the adaptive-steepest-descent-projection-onto-convex-sets (ASD-POCS) algorithm for CBCT image reconstruction. Given a reduced amount of total radiation-dose, we applied both ASD-POCS and FDK algorithms for reconstruction of CBCT images from real measurement data acquired at different mass settings, and investigated how the quality of images reconstructed by these algorithms changes when the amount of total dose is allocated to angular views in different ways. Preliminary results of the study suggest that the ASD-POCS algorithm can yield images of quality better than that achieved by the FDK algorithm with each low-dose data set, and comparable to images obtained with the standard dose level. While FDK image quality degrades with decreased number of views, the ASD-POCS image quality appears to be less affected by different dose-allocation parameters under investigation.