High spatiotemporal vessel-specific hemodynamic mapping with multi-echo single-vessel fMRI.
High-resolution fMRI enables noninvasive mapping of the hemodynamic responses from individual penetrating vessels in animal brains. Here, a 2D multi-echo single-vessel fMRI (MESV-fMRI) method has been developed to map the fMRI signal from arterioles and venules with a 100 ms sampling rate at multiple echo times (TE, 3-30 ms) and short acquisition windows (<1 ms). The T2*-weighted signal shows the increased extravascular effect on venule voxels as a function of TE. In contrast, the arteriole voxels show an increased fMRI signal with earlier onset than venules voxels at the short TE (3 ms) with increased blood inflow and volume effects. MESV-fMRI enables vessel-specific T2* mapping and presents T2*-based fMRI time courses with higher contrast-to-noise ratios (CNRs) than the T2*-weighted fMRI signal at a given TE. The vessel-specific T2* mapping also allows semi-quantitative estimation of the oxygen saturation levels (Y) and their changes (ΔY) at a given blood volume fraction upon neuronal activation. The MESV-fMRI method enables vessel-specific T2* measurements with high spatiotemporal resolution for better modeling of the fMRI signal based on the hemodynamic parameters.
['He|Yi|Y|0000-0003-0040-9255', 'Wang|Maosen|M|', 'Yu|Xin|X|']
D000465:Algorithms D000818:Animals D001160:Arterioles D001810:Blood Volume D001931:Brain Mapping D002560:Cerebrovascular Circulation D017352:Echo-Planar Imaging D007091:Image Processing, Computer-Assisted D008279:Magnetic Resonance Imaging D008297:Male D010101:Oxygen Consumption D051381:Rats D017207:Rats, Sprague-Dawley D014699:Venules
single-vessel fMRI Hemodynamic signal multi-echo fMRI neurovascular coupling vascular dynamics