In a method and apparatus for analyzing medical imaging data of a subject from an imaging modality using a tracer in which a characteristic of the tracer varies with time, are disclosed, a region of interest in a scanned image volume is determined. Data are then obtained from detection of tracer emission events in the scanned imaging volume, and from the data those events which originated in the region of interest are determined. A time series of emission events for the region of interest is then recorded.
