Known-group validity of CT- (left) and MR-based (right) rWTH measures compared with that of other CT- and MR-based linear and volumetric measures of MTL atrophy in patients with AD (open circles) and control subjects (solid circles). Known-group validity of CT- (left) and MR-based (right) rWTH measures compared with that of other CT- and MR-based linear and volumetric measures of MTL atrophy in patients with AD (open circles) and control subjects (solid circles). Solid lines represent regression lines of the measures on age in control subjects. Dotted lines represent age-specific cutoffs that correctly classify 95% of control subjects. Giovanni B. Frisoni et al. AJNR Am J Neuroradiol 2002;23:35-47 ©2002 by American Society of Neuroradiology