  This article is based on the first chapter of book Chung (2013), where brain
and medical images are introduced. The most widely used brain imaging
modalities are magnetic resonance images (MRI), functional-MRI (fMRI) and
diffusion tensor images (DTI). A brief introduction to each imaging modality is
explained. Further, we explain what kind of curve, volume and surface data that
can be extracted from each modality.
