1. A method of stereotactic surface projection of a PET/SPECT image comprising the steps of; (a) spatially normalizing a PET/SPECT image, wherein each voxel on the surface of a brain is registered to a standard space, and (b) calculating SSP for each surface voxel of the spatially normalized PET/SPECT image, wherein, said calculating step further comprises calculating the maximum intensity along a line extending from each surface voxel and perpendicular to the surface into the tissue such that each line extends to a predefined maximum depth that is calculated individually for each surface voxel.