We previously demonstrated that the CBF correlation (CBFcorr) network, constructed with CBF SPECT data, shows a ‘small-world’ architecture [Melie-García et al., 2013] similar to structural correlation networks (Alexander-Bloch et al., 2013, for a review). Moreover, the CBFcorr network reflects a certain extent the cerebral microvascular network since cellular mechanisms at the capillary level mediating the radiotracer uptake in CBF SPECT.