1. A method of determining the degree of uptake of a PET marker in an individual candidate PET scan, the method including the steps of: (a) calculating a series of representative matched controlled PET and MRI templates for a series of controlled sample scans of individuals; (b) computing a series of brain surfaces from the matched templates; (c) aligning the individual candidate PET scan with the matched templates; (d) aligning the series of brain surfaces with the candidate PET scan, wherein each of the brain surfaces aligned with the candidate PET scan includes a plurality of surface locations; (e) selecting M templates for each of the plurality of surface locations based on a similarity measure between the candidate PET scan and a corresponding controlled PET template; (f) computing M weights for each of the plurality of surface locations utilizing a corresponding MRI template tissue map; (g) utilizing the M weights to combine the M templates for each of the plurality of surface locations to form an average brain surface indicator.