Comparison of Time Usage and Success Rate Between CT Angiography- and CT Perfusion- Based Imaging Assessment Strategy for the Patients with Acute Ischemic Stroke

Background: Our study aimed to compare the time usage and success rate between CTA- and CTP- based assessment strategy, and to clarify the risk factors associated with CTP scan failure. Methods: : Clinical and radiological data of 437 consecutive AIS patients who underwent multiphase CTA or CTP for pre-treatment evaluation were retrospectively enrolled (CTA group, n=302; CTP group, n=135). Time usage and success rate of CTA and CTP were compared using Mann-Whitney U test and Chi-Squared Test. Univariate analysis and receiver operating curve analysis were used to clarify the risk factors and their values for predicting CTP scan failure. Results: : Time usage of CTP scan and reconstruction was significantly longer than that of CTA [775sec vs 263.5sec, P<0.001]. CTP scan showed significantly higher failure rate than CTA (11% vs 1%, P<0.001). Severe motion was the most common cause of CTP failure (n=12, 80%). Baseline National Institute of Health Stroke Scale (NIHSS) score in CTP failure group was significantly higher than that in CTP success group [17 vs 13, P=0.007]. Baseline NIHSS score of 11 was the optimal threshold to predict CTP failure with an area under the curve of 0.771, sensitivity of 86.7% and specificity of 45.0%. Conclusions: : CTP-based strategy showed longer time consumption and higher failure rate than CTA-based strategy. High baseline NIHSS score was significantly associated with CTP scan failure in AIS patients.