Abstract TP152: Computed Tomography Perfusion Parameter to Predict Cerebral Hyperperfusion Phenomenon Following Carotid Artery Stenting

Abstract

Background: Although SPECT is useful for predicting and finding cerebral hyperperfusion phenomenon (CHP) following carotid artery stenting (CAS), there are few institutions that could perform SPECT during peri-CAS period. The purpose of our study is to evaluate whether or not parameters derived from CT perfusion (CTP) used widely can predict CHP. Methods: Patients who underwent CTP before elective CAS and SPECT before and immediately after elective CAS in our institution from December 2010 to May 2012. We defined CHP as post-CAS increase of more than 10% of the ratio of cerebral blood flow (CBF) in the territory of the affected middle cerebral artery (MCA) divided by CBF in the ipsilateral cerebellum (MCA/CE ratio) measured by SPECT. We assessed the correlation of pre-CAS CTP’s parameters’ ratio to MCA/CE ratio change between pre-CAS and post-CAS SPECT. The CTP’s parameters’ ratio was calculated as (parameters in the affected side divided by in the unaffected side). CTP parameters we assessed are as follows: time-to-peak (TTP), mean-transit-time (MTT), cerebral blood volume (CBV) and CBF. Results: Fifty patients were analyzed. Pre-CAS TTP ratio showed a significant positive correlation with MCA/CE ratio change (r = 0.2863, p = 0.044). Other parameters (MTT, CBV and CBF) had no significant correlation. The cut-off value of pre-CAS TTP ratio was 1.08 to predict CHP (AUC = 0.77859, p = 0.032). Conclusion: Increase of pre-CAS TTP ratio is probably correlated with CHP following elective CAS.