FIG. 2.

CBF-based resting-state functional connectivity (FC) measurement [Figure adapted with permission from Chuang et al. (2008)]. (a) The resting-state functional magnetic resonance imaging (fMRI) signal spectra show distinct blood oxygen level-dependent (BOLD)-related (<0.08 Hz) and CBF-related (>0.08 Hz) peaks. (b) FC maps of the motor cortex (outlined in green) were derived using high-pass-filtered CASL data (top) and are comparable with the BOLD-based connectivity maps (middle); note that the high-passed BOLD data showed minimal FC (bottom). (c) Composite functional connectivity maps show differential sensitivity of the BOLD- and CBF-based connectivity measures. Color images available online at www.liebertpub.com/brain