Registering

From Waisman Brain Imaging Wiki

Registering brain images is aligning, rotating, translating, and/or deforming individual 2-D or 3-D brain images so that they tomographically or morphometrically match each other as closely as possble. It is done so that areas of interest or activation in different subjects can be compared to a degree. It is also done to contrast activation recorded by different modalities (MRI, PET, EEG, MEG, etc.). Registration can be performed against another image, or against a standard model (for example, an average built up of several previously co-registered brains, or a template derived from an ideal like "Talairach space"). Needless to say, as all human brains are somewhat different in size, shape, and surface features, registration can be quite tricky, and sometimes impossible (for example, in subjects with severe birth defects in the brain or physically degenerative diseases).