Utility of automated MRI perfusion (RAPID) with or without MR angiography for detection of angiographic vasospasm after aneurysmal subarachnoid hemorrhage.

Delayed cerebral ischemia (DCI) is a major etiology of poor neurologic outcomes after aneurysmal subarachnoid hemorrhage (aSAH). Although the development of DCI is certainly multifactorial, the presence of vasospasm is strongly correlated with it. Cerebral angiography remains the gold standard for evaluation of vasospasm, though it is not always practical or cost-effective. In this study, the authors assess the utility of automated MRI Perfusion imaging, with or without MR Angiography (MRA), as a confirmatory tool for suspected angiographic vasospasm. All patients admitted to a single institution with aneurysmal subarachnoid hemorrhage between January 2014 and February 2020 and who underwent MR Perfusion imaging with or without MRA for suspected vasospasm no >24 h prior to an angiogram were identified. 43 subjects were identified. 29 of these patients (67%) underwent simultaneous MRA. 25 patients (53%) received intra-arterial treatment for symptomatic vasospasm. The sensitivity, specificity, PPV, and NPV of MR Perfusion were 43%, 82%, 53%, and 75% for any angiographic vasospasm and 57%, 81%, 42%, and 89% for treated vasospasm. The sensitivity, specificity, PPV, and NPV of MR Perfusion in conjunction with MRA were 61%, 81%, 59%, and 82% for any angiographic vasospasm and 62%, 74%, 35%, and 89% for treated vasospasm. The sensitivity, specificity, PPV, and NPV of transcranial Dopplers (TCDs) in these patients were 35%, 93%, 71%, and 75% for angiographic vasospasm and 42%, 90%, 47%, and 88% for treated vasospasm. Automated MR Perfusion imaging demonstrated relatively low sensitivity and PPV for detection of angiographic and treated vasospasm in this subset of patients after aSAH.