Single Photon Emission Computed Tomography (SPECT) Imaging Study of Professional American Football Players

The investigators primary objective is to acquire preliminary data on one-hundred former NFL veterans with at least one full year of professional service using brain SPECT imaging in order to assess the degree to which NFL football puts players at risk for traumatic brain injury (TBI). TBI severity shall be gauged via visual inspection by a clinician trained in neuroanatomy, and also by a statistical comparison of subjects' brains to an in-house proprietary database comprised of the brains of healthy subjects. The investigators secondary objective is to acquire additional data on these players such that investigators may establish causative factors and risks associated with said TBI. The investigators tertiary objective is to acquire data on subjects using various mental health metrics in order to determine the effects of TBI.