Can CT Perfusion Guide Patient Selection for Treatment of Delayed Cerebral Ischemia?

Abstract

Purpose: To evaluate qualitative and quantitative CT perfusion (CTP) for different treatment options of delayed cerebral ischemia (DCI) in aneurysmal SAH. Methods: Retrospective study of consecutive SAH patients enrolled in a prospective IRB-approved clinical trial. Qualitative analysis of CTP deficits were determined by two blinded neuroradiologists. Quantitative CTP was performed using standardized protocol with region-of-interest placement sampling the cortex. DCI was assessed by clinical and imaging criteria. Patients were classified into treatment groups: 1) hypertension-hemodilution-hypervolemia (HHH); 2) intra-arterial (IA) vasodilators and/or angioplasty; 3) no treatment. Mean quantitative CTP values were compared using ANOVA pairwise comparisons. Receiver operating characteristic (ROC) curves, standard error (SE) and optimal threshold values were calculated. Results: Ninety-six patients were classified into three treatment groups; 21% (19/96) HHH, 34% (33/96) IA-therapy and 46% (44/96) no treatment. DCI was diagnosed in 42% (40/96); of which 18% (7/40) received HHH, 80% (32/40) IA-therapy, and 2% (1/40) no treatment. CTP deficits were seen in 50% (48/96); occurring in 63% (12/19) HHH, 94% (31/33) IA-therapy, and 11% (5/44) no treatment. Presence of CTP deficits had 83% sensitivity, 89% specificity, 90% positive predictive and 81% negative predictive values for treatment. Mean quantitative CTP values revealed significant differences in CBF (p mL/100 gm/min (89% specificity, 71% sensitivity) for determining treatment. Conclusion: These initial findings of significant differences in CTP deficits for different treatment groups suggest that CTP may have a potential role in guiding patient selection for treatment of DCI.