Skull stripping

Skull stripping (also known as brain extraction, brain peeling or head peeling) is a term used to describe the separation of brain and non-brain tissue of the head of vertebrates, and humans in particular.

While having its origins in anatomical dissections (where brain extraction is more commonly used), the term is nowadays mostly employed to describe the application of image segmentation techniques to neuroimaging data of the vertebrate head. Such data are typically acquired in vivo or in situ, i.e. with the brain inside the head of a living or dead subject. To analyze the brain separately (e.g. by means of brain morphometry), its share of the image has to be "peeled off" from the surrounding tissue — mainly the skull, skin and muscles of the head — as well as cerebrospinal fluid.

Algorithms

A common classification of skull stripping algorithms distinguishes between approaches based on mathematical morphology and thresholding, on edge detection, on a priori information, or deformable-surface algorithms. Various combinations thereof are also frequently employed.