Model observer and human observer performance studies in differential phase contrast CT

Abstract

This study investigates the possibility of using the model observer detectability to represent human detection performance in differential phase contrast CT (DPC-CT). Five model observers were investigated, including the prewhitening (PW) observer, the prewhitening observer with eye filter and internal noise (PWEi), the nonprewhitening (NPW) observer, the non-prewhitening observer with eye filter (NPWE), and the channelized Hotelling observer (CHO). Human 2AFC experiments involving four physicist observers were also performed to provide reference to the model observer results. The contrast thresholds required for 92% correct decision rate in 2AFC tests were evaluated for each observer. While all five model observers show good correlations with human observers, the CHO generated the best quantitative agreement with human observer results. Compared with the time-consuming human observer method, the model observer method is of much higher efficiency for the evaluation and optimization of DPC-CT.