title: Can CT angiography rule out aneurysmal subarachnoid haemorrhage in CT scan-negative subarachnoid haemorrhage patients?
abstract: Current management guidelines for CT scan-negative subarachnoid haemorrhage (SAH) patients recommend cerebral digital subtraction angiography (DSA). We aimed to investigate the utility of CT angiography (CTA) as a substitute for DSA in these patients. We included patients who presented with SAH confirmed by spectrophotometric xanthochromia analysis of cerebrospinal fluid (CSF) whereby the CT scan was negative. Electronic records were reviewed to collect data on non-contrast CT scan, CTA and DSA results. Patients without DSA or with other explanations for CSF xanthochromia were excluded. Sixty-three patients with CT scan-negative SAH were included. The diagnosis of SAH was confirmed by CSF analysis. All 63 patients underwent both DSA and CTA. Using DSA as the benchmark, CTA demonstrated a negative predictive value, positive predictive value, sensitivity and specificity of 98%, 82%, 90% and 96%, respectively, for the detection of intracranial aneurysms. CTA correctly identified patients in whom there were no underlying aneurysms responsible for SAH, with one patient with suspected dissection referred for further evaluation using MRI and DSA.
authors: Department of Radiology, The Royal Melbourne Hospital, Grattan Street, Parkville, VIC 3050, Australia.
authors: Lee Kai
authors: LK
authors: Lim
authors: Department of Radiology, The Royal Melbourne Hospital, Grattan Street, Parkville, VIC 3050, Australia.
authors: Richard J
authors: RJ
authors: Dowling
authors: Melbourne Brain Centre, The Royal Melbourne Hospital, Melbourne, VIC, Australia; Department of Medicine, Faculty of Medicine, University of Melbourne, Melbourne, VIC, Australia.
authors: Bernard
authors: B
authors: Yan
authors: Department of Radiology, The Royal Melbourne Hospital, Grattan Street, Parkville, VIC 3050, Australia. Electronic address: peter.mitchell@mh.org.au.
authors: Peter J
authors: PJ
authors: Mitchell
mesh_terms: D015901:Angiography, Digital Subtraction; D002533:Cerebral Angiography / Q000379:methods*; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: CT angiography; CT negative; Intracranial aneurysm; Normal CT; Subarachnoid haemorrhage