ROI-dependence in clarifying metabolic connectivity mapping within default-mode network using simultaneous FDG PET and BOLD-based fMRI

Metabolic connectivity mapping (MCM) is a unique application of simultaneous PET/fMRI for solving the effective connectivity (EC) of brain circuits. Reproducibility of MCM was critical after the initial report. By applying the released database of MONASH (Melbourne, Australia), consistent EC among bilateral inferior parietal lobules (IPL) and posterior cingulate cortices (PCC), as nodes within default mode network (DMN), was identified using MCM with the statistic-based approach. One-way EC using dedicated ROI (regions of interest) derived from grouped ICA (independent component analysis) outperformed the atlas-based ROIs of DMN.