CT image reconstruction design by investigation of the propagation of Hotelling SNR

In this work, we investigate the performance of the Hotelling observer for a signal detection task in order to characterize the inherent signal detectability preservation in CT image reconstruction algorithms. Filtered back-projection (FBP) is taken as an illustrative case. We then undertake the same evaluation of the back-projection filtration (BPF) algorithm developed by our group [1]. The analysis is performed in such a way that we are able to quantify not only the total information lost through reconstruction, but also the amount of information lost due to unequal detector bin variances versus information lost through discretization. The modeled signal for detection is taken to be very small - size on the order of a detector bin - and inspection of the closest consistent sinogram to the original projection data is suggested. We hypothesize that detection of small signals may be sensitive to variations in the implementation of the reconstruction algorithm.