Acetazolamide-Challenged Brain CT Perfusion before and after Carotid Stenting

Kim, Ho Sung; Kim, Eun Jin; Kim, Sun Yong

Abstract

PURPOSE
To test hypothesis that pre-stenting measurement of reactivity index by using acetazolamide-challenged CT perfusion could identify patients at risk for hyperperfusion after carotid stenting.
MATERIALS AND METHODS
For 24 regions of interest in 12 patients with symptomatic unilateral high-grade carotid stenosis, asymmetric indexes for cerebral blood volume, cerebral blood flow, and mean transit time and reactivity index were calculated from resting and acetazolamide-challenged CT perfusion before and 1 day after carotid stenting. We subsequently compared pre-stenting asymmetric indexes and reactivity index with percent increase of cerebral blood flow 1 day after carotid stenting.
RESULTS
Percent increase of cerebral blood flow on the first post-stenting day was not significantly different between visually decreased and normal cerebrovascular reserve groups. There was no significant correlation between pre-stenting asymmetric indexs of resting CT perfusion parameters and percent increase of cerebral blood flow 1 day after carotid stenting. On the other hand, pre-stenting reduction of reactivity index showed fair correlation with 1 day cerebral blood flow increase. However, hyperperfusion or hyperperfusion syndrome was not observed in any patient with reduced reactivity index.
CONCLUSION
Pre-stenting measurements of resting CT perfusion parameters and reactivity index could not predict hyperperfusion after carotid stenting. However, pre-stenting reduction of reactivity index seems to fairly correlate with immediate post-stenting cerebral blood flow increase. Further studies with larger population should be performed to validate this preliminary result.