Model of vascular reactivity to investigate the basis of Grubb's relationship between cerebral blood flow and volume
Piechnik S, Jezzard P, Chiarelli P
University of Oxford
The relationship between cerebral blood volume and flow is important in order to understand the mechanisms of functional imaging contrast and enable calculation of cerebral metabolic ratio. We analyse several models of cerebral circulation including a novel multicompartmental model based on a meta-analysis of studies directly measuring vascular reactivity. The shape of the volume-flow relationship depends strongly on the choice of the model and the contribution of autoregulating segments in the volume of interest. Even though the former can be neglected under physiological conditions, the latter may contribute significantly to the focal characteristics of imaging contrast.