“Now we can assess how well the brain regulates blood flow, and even detect brain activation noninvasively in adult humans, using principles similar to functional magnetic resonance imaging (fMRI), but at a fraction of the cost,” said Vivek Srinivasan, adjunct associate professor of biomedical engineering at UC Davis and senior author on the study. The human brain makes up two per cent of human body weight but takes 15 per cent to 20 per cent of blood flow from the heart. Measuring cerebral blood flow is important for diagnosing strokes, and for predicting secondary damage in subarachnoid hemorrhages or traumatic brain injuries.