title: Preoperative evaluation of unruptured cerebral aneurysms by fast imaging employing steady-state acquisition image.
abstract: BACKGROUND
  In aneurysm surgery, understanding the microanatomy around the aneurysm such as perforating arteries and cranial nerves is mandatory.
  
  
  OBJECTIVE
  To assess the usefulness in determining the microanatomy around the cerebral aneurysms by the use of fast imaging employing steady-state acquisition (FIESTA) images of magnetic resonance imaging preoperatively, in addition to computed tomography and digital subtraction angiography.
  
  
  METHODS
  Between October 2006 and June 2009, 123 patients with 140 unruptured cerebral aneurysms were treated in our institution. Eighty-two patients were assessed with FIESTA by the operators on the workstation of the magnetic resonance image before surgical clipping of the aneurysms. The small vessels and cranial nerves were confirmed intraoperatively before or after obliteration of the aneurysms.
  
  
  RESULTS
  Sensitivities and specificities of FIESTA imaging were 100% in detecting hypothalamic artery around anterior communicating artery aneurysms, oculomotor nerve attachment to the posterior communicating artery aneurysm domes, and anterior choroidal artery adhesion to the posterior communicating artery aneurysms. This technique was also useful for predicting adhesion between the aneurysm and adjacent main trunks or perforators. Although the specificity was 100%, sensitivity was 56% in detecting vessel adhesion around the middle cerebral aneurysms. This technique can provide limited information in large aneurysms or aneurysms located in minimal cerebrospinal fluid space. The overall outcomes of the patients included 120 excellent recoveries, 1 moderate deficit, 1 severe deficit, and 1 persistent vegetative state according to the Glasgow Outcome Scale.
  
  
  CONCLUSIONS
  By giving information on the minute anatomical structure around the aneurysm, FIESTA can contribute to thorough preoperative evaluations of cerebral aneurysms.
authors.affiliation: Department of Neurosurgery and Stroke Unit, NTT Medical Center Tokyo, Tokyo, Japan. tkim-tky@umin.ac.jp
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Kimura
authors.forename: Akio
authors.initials: A
authors.lastname: Morita
authors.forename: Ichiro
authors.initials: I
authors.lastname: Shirouzu
authors.forename: Shigeo
authors.initials: S
authors.lastname: Sora
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D002532:Intracranial Aneurysm / Q000473:pathology* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D057234:Preoperative Period; D012680:Sensitivity and Specificity; D013997:Time Factors