In-depth analysis of cone-beam CT image reconstruction by ideal observer performance on a detection task

We have recently perform evaluations, of the back-projection filtration (BPF) algorithm for cone-beam CT image reconstruction, based on ideal observer performance for signal detection. The metric used is the efficiency, which is here the squared ratio of the signal detection signal-to-noise ratios (SNRs) in the reconstructed image and in the projection data. We have generally found that efficiencies fall in the range of 75%–85% for minimum projection-data scans. We hypothesize that the efficiency should approach 100% for minimum data scans. In this work, we evaluate the individual steps in the BPF algorithm to identify, and possibly remedy, the loss of SNR due to the algorithm implementation. For the detection task specified here, the efficiency is improved from 82% to 96% by using this detailed analysis.