Detecting vasomotion of awake mice with 14T CBV fMRI

Motivation: Vasomotion, rhythmic blood vessel diameter changes around 0.1Hz, is a key contributor to resting-state fMRI signals. In contrast to 2-PM studies mapping the cortical surface vessels, high-resolution CBV fMRI enables brain-wide investigation of unique vasodynamic changes. Goal(s): To investigate cortex-wide vasomotion in awake mice with high-resolution CBV fMRI. Approach: Using high-resolution CBV fMRI and spatial frequency SVD analysis, we mapped frequency-specific coherence magnitude and phase patterns (0.05-0.2 Hz) across the cortex of awake mice. Results: We observed time-varying coherence dynamics and distinct spatial patterns, underlying CBV rs-fMRI fluctuations. The 3D phase gradient (~0.3 rad/mm) showed unique propagation from occipital to prefrontal areas. Impact: We applied high-resolution CBV fMRI to identify vasomotion-related spatial coherence patterns in awake mice. Bandwidth-specific phase gradient analysis presents a ~2mm/s propagation wave across the cortex.