title: Diagnostic yield of delayed neurovascular imaging in patients with subarachnoid hemorrhage, negative initial CT and catheter angiograms, and a negative 7 day repeat catheter angiogram.
abstract: OBJECTIVE
  The yield of delayed neurovascular imaging in patients with subarachnoid hemorrhage (SAH), negative initial CT and catheter angiograms (CT angiography (CTA), DSA), and negative 7 day repeat DSA is not well understood. Our aim was to determine the yield of delayed neurovascular imaging for the detection of causative vascular lesions in this clinical scenario.
  
  
  METHODS
  We retrospectively examined the yield of delayed CTA and DSA for the detection of causative vascular lesions in patients presenting to our institution with SAH, negative initial CTA and DSA examinations, and a negative 7 day repeat DSA during a 6.5 year period. Two neuroradiologists evaluated the non-contrast CTs to determine the SAH pattern, and the delayed CTAs and DSAs to assess for the presence of a causative vascular lesion.
  
  
  RESULTS
  39 patients were included: 23 men (59%) and 16 women (41%), mean age 55.5 years (range 33-75). 25 patients had diffuse SAH (64.1%), 12 had perimesencephalic SAH (30.8%), and two had peripheral sulcal SAH (5.1%). The delayed neurovascular examination was CTA in 30 patients (76.9%) and DSA in nine patients (23.1%). Mean time to delayed CTA or DSA was 34.9 days (median 34, range 14-69 days). Delayed CTA demonstrated a causative vascular lesion in two patients (5.1%, one small internal carotid artery aneurysm and one small pontine arteriovenous malformation), both with diffuse SAH (yield 8%).
  
  
  CONCLUSIONS
  Delayed neurovascular imaging is valuable in the evaluation of patients with diffuse SAH who have negative initial CTA and DSA examinations and a negative 7 day repeat DSA, demonstrating a causative vascular lesion in 8% of patients.
authors.affiliation: Division of Interventional Neuroradiology, Neuroscience Institute, Abbott Northwestern Hospital, Minneapolis, Minnesota, USA.
authors.forename: Josser E
authors.initials: JE
authors.lastname: Delgado Almandoz
authors.affiliation: Division of Interventional Neuroradiology, Neuroscience Institute, Abbott Northwestern Hospital, Minneapolis, Minnesota, USA.
authors.forename: Yasha
authors.initials: Y
authors.lastname: Kadkhodayan
authors.affiliation: Division of Interventional Neuroradiology, Neuroscience Institute, Abbott Northwestern Hospital, Minneapolis, Minnesota, USA.
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Crandall
authors.affiliation: Division of Interventional Neuroradiology, Neuroscience Institute, Abbott Northwestern Hospital, Minneapolis, Minnesota, USA.
authors.forename: Jill M
authors.initials: JM
authors.lastname: Scholz
authors.affiliation: Division of Interventional Neuroradiology, Neuroscience Institute, Abbott Northwestern Hospital, Minneapolis, Minnesota, USA.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Fease
authors.affiliation: Division of Interventional Neuroradiology, Neuroscience Institute, Abbott Northwestern Hospital, Minneapolis, Minnesota, USA.
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Anderson
authors.affiliation: Division of Interventional Neuroradiology, Neuroscience Institute, Abbott Northwestern Hospital, Minneapolis, Minnesota, USA.
authors.forename: David E
authors.initials: DE
authors.lastname: Tubman
mesh_terms: D000328:Adult; D000368:Aged; D015901:Angiography, Digital Subtraction / Q000592:standards*; D002533:Cerebral Angiography / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging*; D013997:Time Factors
keywords: Aneurysm; Angiography; Arteriovenous Malformation; CT Angiography; Subarachnoid