AD subtypes based on patterns of brain atrophy. Regional atrophy was measured with the MTA, PA, and GCA-F visual rating scales based only on T1-weighted images. In the 3 visual rating scales, a score of zero denotes no atrophy, whereas scores from 1 to 3 (PA and GCA-F) or 4 (MTA) indicate an increasing degree of atrophy. The typical AD subtype was defined as abnormal MTA together with abnormal PA and/or abnormal GCA-F. The limbic-predominant subtype was defined as abnormal MTA alone with normal PA and GCA-F. The hippocampal-sparing subtype included abnormal PA and/or abnormal GCA-F but normal MTA. The minimal atrophy subtype was defined as normal scores in MTA, PA, and GCA-F. The figure shows examples of each subtype in axial and coronal sections of the brain. AD, Alzheimer’s disease; MTA, medial temporal atrophy scale; PA, posterior atrophy scale; GCA-F, global cortical atrophy scale – frontal subscale; A, anterior part of the brain; P, posterior part of the brain; R, right; L, left.