Measurement of Cerebral Blood Flow and Cerebral Blood Volume in Humans Using Washout of Hyperoxic Contrast

David Thomas Pilkinton¹, Santosh Gaddam¹, Mark A. Elliott¹, Ravinder Reddy¹

It has long been thought that hyperoxia alters the hemodynamics of the brain substantially, confounded attempts to measure hemodynamic quantities with hyperoxic contrast. However, recent studies have shown that cerebral blood flow (CBF) experiences only a small (<4%) reduction upon breathing low to moderate oxygen concentrations (FiO2≤0.5). . Since hyperoxic contrast exhibits fast washout times, accurate measurements of dynamic parameters are feasible. We have shown here that that accurate measurements of CBV and CBF can be made dynamically during the washout of hyperoxic contrast using indicator-dilution theory in a manner akin to traditional dynamic susceptibility contrast (DSC) measurements.