Cerebral blood volume in T2-weighted white matter hyperintensities using exogenous contrast based perfusion MRI.

We used perfusion weighted magnetic resonance imaging (MRI) to determine relative regional cerebral blood volume (rCBV) in regions of white matter hyperintensity (WMH) in 28 elderly stroke patients and 27 healthy comparison subjects, using T2-weighted fluid-attenuated inversion recovery (FLAIR) sequence MRI for anatomical localization and bolus gadolinium-DTPA tracking for perfusion weighted imaging. We found that WMHs had significantly lower rCBV than contralateral normal WMH, irrespective of size or group membership, and rCBV was significantly related to the size of the WMH. For the larger WMHs, there was a significant increase in rCBV from inner core to outer ring. The findings suggest hemodynamic perturbation in the microvasculature of hyperintense regions, which becomes greater as the size of the WMH increases. This is equally applicable to stroke patients and healthy older individuals.