FIG. 6.

Measuring neurometabolic mechanisms of resting-state fMRI using ASL: (a) The resting-state relationship between BOLD and CBF [Reprinted with permission from Fukunaga et al. (2008)]. The relationship between BOLD and CBF fluctuations in the resting state is shown to be strongly linear. Furthermore, this CBF-BOLD relationship was shown to be similar to that observed during visual stimulation (VT) and breath holding (BH). (b) The derivation of dynamic oxidative metabolism (CMRO₂) and FC from simultaneous CBF-BOLD data [Reprinted with permission from Wu et al. (2009)]. CMRO₂ was derived based on the linear approximation of the CBF-BOLD relationship. Futhermore, FC maps, computed from resting-state BOLD, CBF, and CMRO₂ time courses, are spatially consistent in multiple functional networks, including the visual, hippocampal, and DMNs. Color images available online at www.liebertpub.com/brain