Pelin Aksit Ciris1, Maolin Qiu1, Robert Todd Constable1
1Yale University, New Haven, CT, United States
BOLD signal reflects changes in CBV, CBF, blood oxygenation and metabolism, the quantification and physiological interpretation of which typically assumes that CBV=0.88CBF0.38 based on PET monkey measurements by Grubb et al. In this study, the absolute CBV-CBF relationship was measured directly in MRI non-invasively on 12 volunteers during visual stimulation. Measurements were within physiologically expected ranges, consistent with prior PET and contrast enhanced results in cortical GM. Non-invasive characterization of the CBV-CBF relationship in humans under various metabolic or functional challenges can advance understanding of fMRI signal mechanisms, with further potential clinical utility in vascular state or treatment monitoring.