BACKGROUND AND PURPOSE: rtPA is an effective treatment for AIS, yet it is substantially underused due to the increased risk of HT. Recent work suggests that permeability-related information can be extracted from routine T2*-based perfusion images by measuring the rR of the contrast agent. Given that other T2*-based measures have recently been proposed, the purpose of this study was to evaluate 4 such permeability measures in identifying patients with AIS who will proceed to HT.

Both KPS and rR are significantly elevated in infarcted, relative to uninfarcted tissue in the same AIS patient. Both parameters were also significantly elevated in HT, relative to non-HT infarcts. The strong correlation between rR and KPS, coupled with the high sensitivity and specificity of rR for the prediction of HT suggest that rR is related to blood-brain barrier integrity in AIS and may prove valuable in the prediction of HT.