Feasibility of Flat-Panel CT-Based Perfusion Imaging for Early Diagnosis of Symptomatic Cerebral Vasospasm After Subarachnoid Hemorrhage

This case study aims to describe the utility of RAPID for ANGIO software (RAPID ANGIO), a flat-panel detector CT-based perfusion and CT angiography-like imaging tool, in the supplementary diagnosis of symptomatic cerebral vasospasm (CVS) following subarachnoid hemorrhage (SAH). Three SAH patients were suspected of having symptomatic CVS, manifested by sudden disturbances of consciousness or focal neurological deficits during the periprocedural period of endovascular treatment (EVT) for ruptured intracranial aneurysms. RAPID ANGIO was used to evaluate vessel narrowing, infarct core, and hypoperfused tissue (defined as time-to-maximum; Tmax >6 seconds), after excluding new hemorrhages using flat-panel CT in the angiosuite. Case 1: A 36-year-old woman developed right hemiparesis and aphasia nine days after SAH. RAPID ANGIO revealed left middle cerebral artery (MCA) narrowing and a substantial penumbra without an infarct core. Angiography confirmed severe vasospasm, and EVT resulted in clinical improvement. Case 2: A 73-year-old woman developed impaired consciousness 11 days after SAH. RAPID ANGIO revealed diffuse right MCA narrowing and mildly delayed perfusion (Tmax >4 seconds). Although EVT was performed, ischemia occurred in the corresponding region. Case 3: A 76-year-old woman experienced transient aphasia 13 days after SAH. RAPID ANGIO revealed no infarct core or penumbra despite possible vessel narrowing. Angiography confirmed the absence of CVS. No further ischemic symptoms occurred. RAPID ANGIO enables rapid, integrated assessment of cerebral perfusion and vascular narrowing in symptomatic CVS. It may serve as a valuable adjunct to guide angiography and EVT decisions in patients with suspected CVS following SAH.