title: Nontraumatic subarachnoid hemorrhage management: evaluation with reduced iodine volume at CT angiography.
abstract: OBJECTIVE
  To evaluate the technical quality and the diagnostic performance of a protocol with use of low volumes of contrast medium (25 mL) at 64-detector spiral computed tomography (CT) in the diagnosis and management of adult, nontraumatic subarachnoid hemorrhage (SAH).
  
  
  METHODS
  This study was performed outside the United States and was approved by the institutional review board. Intracranial CT angiography was performed in 73 consecutive patients with nontraumatic SAH diagnosed at nonenhanced CT. Image quality was evaluated by two observers using two criteria: degree of arterial enhancement and venous contamination. The two independent readers evaluated diagnostic performance (lesion detection and correct therapeutic decision-making process) by using rotational angiographic findings as the standard of reference. Sensitivity, specificity, and positive and negative predictive values were calculated for patients who underwent CT angiography and three-dimensional rotational angiography. The intraclass correlation coefficient was calculated to assess interobserver concordance concerning aneurysm measurements and therapeutic management.
  
  
  RESULTS
  All aneurysms were detected, either ruptured or unruptured. Arterial opacification was excellent in 62 cases (85%), and venous contamination was absent or minor in 61 cases (84%). In 95% of cases, CT angiographic findings allowed optimal therapeutic management. The intraclass correlation coefficient ranged between 0.93 and 0.95, indicating excellent interobserver agreement.
  
  
  CONCLUSIONS
  With only 25 mL of iodinated contrast medium focused on the arterial phase, 64-detector CT angiography allowed satisfactory diagnostic and therapeutic management of nontraumatic SAH.
authors.affiliation: Department of Diagnostic and Therapeutic Neuroradiology, Centre Hospitalo Universitaire Nancy, Department of Anatomy, Faculty of Medicine, Université de Lorraine, Vandoeuvre Les Nancy, France. domillon@hotmail.com
authors.forename: Domitille
authors.initials: D
authors.lastname: Millon
authors.forename: Anne Laure
authors.initials: AL
authors.lastname: Derelle
authors.forename: Patrick
authors.initials: P
authors.lastname: Omoumi
authors.forename: Marie
authors.initials: M
authors.lastname: Tisserand
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Schmitt
authors.forename: Sylvain
authors.initials: S
authors.lastname: Foscolo
authors.forename: René
authors.initials: R
authors.lastname: Anxionnat
authors.forename: Serge
authors.initials: S
authors.lastname: Bracard
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002533:Cerebral Angiography / Q000379:methods*; D003287:Contrast Media; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007479:Iopamidol / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging* / Q000628:therapy*; D036542:Tomography, Spiral Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; C057937:iomeprol; D007479:Iopamidol