Evaluating CT Perfusion Using OutcomeMeasures of Delayed

BACKGROUND AND PURPOSE: DCI is a serious complication following aneurysmal SAH and remains a leading cause of morbidity and mortality. Our aim was to evaluate CTP in aneurysmal SAH by using outcome measures of DCI. MATERIALS AND METHODS: This was a retrospective study of consecutive patients with SAH enrolled in a prospective institutional review board–approved clinical accuracy trial. Qualitative CTP deficits were determined by 2 neuroradiologists blinded to clinical and imaging data. Quantitative CTPwas performed by using a standardized protocol with region-of-interest placement sampling of the cortex. Primary outcome measures were permanent neurologic deficits and infarction. The secondary outcome measure was DCI, defined as clinical deterioration. CTP test characteristics (95 % CI) were determined for each outcomemeasure. Statistical significance was calculated by using the Fisher exact and Student t tests. ROC curves were generated to determine accuracy and threshold analysis. RESULTS: Ninety-six patients were included. Permanent neurologic deficits developed in 33 % (32/96). CTP deficits were seen in 78% (25/32) of those who developed permanent neurologic deficits and 34 % (22/64) of those without (P .0001). CTP deficits had 78% (61%–89%) sensitivity, 66 % (53%–76%) specificity, and 53 % (39%–67%) positive and 86 % (73%–93%) negative predictive values. Infarction occurred in 18 % (17/96). CTP deficits were seen in 88 % (15/17) of those who developed infarction and 41 % (32/79) of those without (P .0004). CTP deficits had an 88 % (66%–97%) sensitivity, 59 % (48%–70%) specificity, and 32 % (20%–46%) positive and 96 % (86%–99%) negative predictive values. DCI was diagnosed in 50 % (48/96). CTP deficits were seen in 81 % (39/48) of patients with DCI and in 17 % (8/48) of those without (P .0001). CTP deficits had 81 % (68%–90%) sensitivity, 83 % (70%–91%) specificity, and 83 % (70%–91%) positive and 82