Computed Tomography Perfusion Deficits during the Baseline Period in Aneurysmal Subarachnoid Hemorrhage Are Predictive of Delayed Cerebral Ischemia

Abstract

Background and purpose: Delayed cerebral ischemia (DCI) is a frequent and fearful complication following aneurysmal subarachnoid hemorrhage (aSAH). The aim of this study is to assess the diagnostic accuracy of computed tomography perfusion (CTP) during an admission baseline period for the prediction of DCI.

Methods: Fifty-four aSAH cases were screened by baseline CTP within 3 days after aSAH and were reexamined with CTP 7-17 days after aSAH. Relative cerebral blood volume, relative cerebral blood flow (CBF), and relative mean transit time were measured. DCI was confirmed by a combination of noncontrast CT, CTP reexamination, and clinical assessment of neurologic deficits. Quantitative baseline and reexamination CTP data for all patients were compared between DCI and without DCI groups using Student's t-tests. The quantitative baseline and reexamination CTP data of DCI patients were compared using paired Student's t-tests. The χ² test was used to evaluate incidences of DCI between different baseline relative CBF levels. The optimal cutoff value for each parameter was established by receiver operating characteristic curve analysis.

Results: Of the patients included in this study, 33.3% (18 of 54) developed DCI. There was a significant difference in the incidence of DCI among different baseline relative CBF subsets (χ² = 38.00, P < .05). A relative CBF of .84 had the highest specificity and sensitivity of predicting DCI.

Conclusion: CTP parameters during the baseline period can be helpful for the early identification of aSAH patients who are at high risk for DCI.

Keywords: Aneurysm; cerebral ischemia; perfusion; subarachnoid hemorrhage.