Initial Slope Index of Total Cerebral Blood Flow Measured by Hydrogen Clearance: a Pragmatic Evaluation

An initial slope index of total cerebral blood flow, measured by hydrogen clearance from torcular blood, shows high correlation with flows calculated by bicompartmental analysis. In 247 flow measurements done on 41 rhesus monkeys, a linear regression analysis between these two methods of calculating flow shows a correlation coefficient of 0. 9280 with a standard error about y values of +7. 63. The initial slope index is not only faster to calculate but does not require that a steady state be maintained for 10 minutes.