Comparison between TOF and non-TOF PET using a scan statistic numerical observer

Two dimensional time-of-flight (TOF) and non-TOF PET image sets are analyzed using a scan statistic (or maximum noise nodule search) observer, as well as a fixed position observer. The results reveal significant differences between the two approaches and indicate that the usual fixed position detectability evaluation techniques, often referred as signal known exactly background known exactly (SKE/BKE) evaluation tasks, insufficiently capture the true nature of image quality improvement that TOF information brings. We review here several results of the detection with localization theory and present a generalization using the noise nodule distribution in a given search area.