The current study builds on our earlier work [Melie-GarcĂ­a et al., 2013] to assess vasodilatory-induced changes in the CBFcorr network in MCI. For this purpose, we constructed four CBFcorr networks: two using CBF SPECT data at baseline and under acetazolamide (ACZ) challenge, obtained from a group of relatively young MCI patients with limited vascular risk factors; and two equivalent networks using a group of matched cognitive normal controls. ACZ is reproducible, simple, and safe vasodilatory stimulus to study CVR (Vagal et al., 2009, for a review).