Early quantitative CT perfusion parameters variation for prediction of delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage.

Abstract

To prospectively evaluate the predictive value of cerebral perfusion-computerized tomography (CTP) parameters variation between day0 and day4 after aneurysmal subarachnoid haemorrhage (aSAH). Mean transit time (MTT) and cerebral blood flow (CBF) values were compared between patients with delayed cerebral ischemia (DCI+ group) and patients without DCI (DCI- group) for previously published optimal cutoff values and for variations of MTT (ΔMTT) and of CBF (ΔCBF) values between day0 and day4. DCI+ was defined as a cerebral infarction on 3-months follow-up MRI. Among 47 included patients, 10 suffered DCI+. Published optimal cutoff values did not predict DCI, either at day0 or at day4. Conversely, ΔMTT and ΔCBF significantly differed between the DCI+ and DCI- groups, with optimal ΔMTT and ΔCBF values of 0.91 seconds (83.9 % sensitivity, 79.5 % specificity, AUC 0.84) and -7.6 mL/100 g/min (100 % sensitivity, 71.4 % specificity, AUC 0.86), respectively. In multivariate analysis, ΔCBF (OR = 1.91, IC95% 1.13-3.23 per each 20 % decrease of ΔCBF) and ΔMTT values (OR = 14.70, IC95% 4.85-44.52 per each 20 % increase of ΔMTT) were independent predictors of DCI. Assessment of MTT and CBF value variations between day0 and day4 may serve as an early imaging surrogate for prediction of DCI in aSAH. • CT perfusion values are an imaging surrogate for prediction of DCI. • Early variations (day0-day4) after aneurysmal subarachnoid haemorrhage predicted DCI. • A CBF decrease of 7.6 mL/min/100 g predicted DCI with 100 % sensitivity. • An MTT increase of 0.91 seconds predicted DCI with 83.9 % sensitivity. • DCI risk multiplied by 2 per 20 % ΔCBF decrease and by 15 per 20 % ΔMTT increase.