Fig. 1
From: Differential response to donepezil in MRI subtypes of mild cognitive impairment
Conceptual framework of AD subtyping dimensions. In this study, we selected a global brain atrophy index (BV/CSF index; [29]) as a proxy for the severity dimension, and the ratio between the volume of the hippocampus to the volume of the cortex as a proxy for the typicality dimension [18, 19]. The combination of severity and typicality dimensions indicates four distinct MRI patterns: typical AD, limbic-predominant, hippocampal-sparing, and minimal atrophy. Adapted from Ferreira et al. [17]