1. A method for segmenting a medical data set, comprising the steps of: acquiring an overview data set of a subject non-contemporaneously with generating at least one marking on said overview data set, by storing said overview data set in a memory, and retrieving said overview data set from said memory to generate said at least one marking; subsequently acquiring a diagnostic data set, different from said overview data set, from the subject using said at least one marking; and segmenting said diagnostic data set using the same at least one marking that was generated on said overview data set.