Characterization of Resting Microvascular Dynamics in Skeletal Muscle Using Synchrosqueezing Transform of BOLD MRI and NIRS

Spatial and temporal regulation of microvascular blood flow impact delivery of oxygen and nutrients to skeletal muscle. We examine temporal patterns in blood oxygenation leveldependent MRI from the calf muscle at rest in healthy subjects and compare with simultaneously acquired optical spectroscopy using a custom near-infrared system. Colocalized time series data are characterized using wavelet synchrosqueezing transform, and preliminary analysis shows inter-subject variability in endothelial functions as well as comparable energy distribution between modalities. This approach holds potential for detailed mapping of microvascular impairment.