A brain atlas is an anatomical atlas of the brain, i.e. a reference work in which brain structures are placed in a coordinate system that is standardized for a given species or developmental stage. Several neuroimaging techniques can be used to obtain the images for brain atlas construction, e.g. from histology or — increasingly common — from MRI scans of one or many or entire brains or cerebral hemispheres.
Apart from providing a common coordinate system for imaging data obtained from different sources (e.g. from a number of patients), brain atlases can be partitioned and labeled, thus providing for atlas-based segmentation of images and for the construction of brain maps. Much like geographic maps can be populated with information about physical, political, economic or environmental aspects of a region of interest, brain maps may include information about genetic, developmental, evolutionary or physiological or pathological aspects of the brain.