1. A method of classifying a brain, the method comprising: receiving image data associated with a head scan including image data of a brain and a brain cortex; segmenting image data associated with a brain cortex from the image data associated with the head scan; generating a three dimensional (3D) mesh model of the segmented brain cortex; mapping the 3D mesh model to a corresponding unit sphere; computing a number of spherical harmonics required to delineate the unit sphere to the 3D mesh model; and classifying the brain using a learned shape model based at least in part on the computed number of spherical harmonics required to delineate the unit sphere to the 3D mesh model.