title: Compartment-resolved imaging of cortical functional hyperemia with OCT angiography.
abstract: Optical Coherence Tomography (OCT) angiography was applied to image functional hyperemia in different vascular compartments in the rat somatosensory cortex. Dynamic backscattering changes, indicative of changes in dynamic red blood cell (dRBC) content, were used to monitor the hemodynamic response. Three-dimensional movies depicting the microvascular response to neuronal activation were created for the first time. An increase in the attenuation coefficient during activation was identified, and a simple normalization procedure was proposed to correct for it. This procedure was applied to determine compartment-resolved backscattering changes caused by dRBC content changes during functional activation. Increases in dRBC content were observed in all vascular compartments (arterial, arteriolar, capillary, and venular), with the largest responses found in the arterial and arteriolar compartments. dRBC content increased with dilation in arteries but with barely detectable dilation in veins. dRBC content increased in capillaries without significant "all or none" capillary recruitment.
authors.affiliation: Biomedical Engineering Department, University of California Davis, Davis, CA 95616, USA ; Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA.
authors.forename: Harsha
authors.initials: H
authors.lastname: Radhakrishnan
authors.forename: Vivek J
authors.initials: VJ
authors.lastname: Srinivasan
keywords: (110.4500) Optical coherence tomography; (170.0180) Microscopy; (170.1470) Blood or tissue constituent monitoring; (170.3880) Medical and biological imaging; (170.6900) Three-dimensional microscopy; (290.1350) Backscattering