The Blood Oxygenation Level Dependent (BOLD) signal is widely recognized in functional MRI studies of the brain. However, there exists a non-functional variant of the BOLD signal, reflecting the balance of oxygen supply and demand in the brain's basal state. This signal is likely linked to the brain's basal energy metabolism. In this study, we aimed to investigate the basal state BOLD signal by analyzing resting-state fMRI time series data. Our findings reveal significant slow oscillations of non-functional dynamic signals, superimposed on the combined basal static non-functional signal and anatomical structures. This analysis produced a map of the apparent transverse relaxation rate (R2*) in the basal state, showing spatial variations and localized segregation in specific brain regions, distinguishable by R2* changes within slice planes. These insights advance our understanding of both functional and non-functional BOLD dynamics in the brain.
Sung et al. (Mon,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: