In methods and an apparatus for detecting an incident or behavior in a medical image scan of a subject, a list of image data points captured during the scan is obtained, and a scan period of the scan selected. A model for a distribution of list data over the scan period is obtained, the model at least in part based on the list data from the scan period. List data are compared with the model, by calculating a statistical measure of the self-consistency of the list data with reference to the model.
