title: Comparison of 2D digital subtraction angiography and 3D rotational angiography in the evaluation of dome-to-neck ratio.
abstract: OBJECTIVE
  Dome-to-neck ratio of intracranial aneurysms is an important predictor of outcomes of endovascular coiling. 3D imaging techniques are increasingly used in evaluating the dome-to-neck ratio of aneurysms for intervention. The purpose of this study was to determine whether 3D rotational angiography (3DRA) can be used to determine accurately the dome-to-neck ratio of intracranial aneurysms when compared with conventional 2D digital subtraction angiography (2D DSA).
  
  
  METHODS
  A retrospective analysis of 180 patients with 205 intracranial aneurysms who underwent both 2D DSA and 3DRA for evaluation of previously untreated aneurysms was conducted. Dome-to-neck ratios were compared between 2D DSA and 3DRA images. The mean difference in dome-to-neck ratios between 2D DSA and 3DRA was calculated. The proportions of "wide-neck" aneurysms seen on 2D DSA and 3DRA were compared by using 2 different definitions of "wide-neck," including <1.5 and <2.0.
  
  
  RESULTS
  The average dome-to-neck ratio was 1.81 +/- 0.55 and 1.55 +/- 0.48 for 2D DSA and 3DRA, respectively (P < .0001). When we defined "wide-neck" as a dome-to-neck ratio <1.5, sixty-nine (33.7%) aneurysms were wide-neck on 2D DSA compared with 119 (58%) on 3DRA (P < .0001). When we defined "wide-neck" as dome-to-neck ratio <2.0, one hundred forty-two (69.3%) aneurysms were wide-neck on 2D DSA compared with 173 (84.4%) on 3DRA (P = .0004).
  
  
  CONCLUSIONS
  In this retrospective study, 3DRA measurements resulted in significantly lower dome-to-neck ratios and significantly larger proportions of aneurysms defined as "wide-neck" compared with 2D DSA. Scrutiny of 2D DSA may offer substantial benefit over 3D techniques when triaging patients to or from endovascular therapy.
authors.affiliation: Mayo Medical School, Mayo Clinic, Rochester, Minn. 55905, USA.
authors.forename: W
authors.initials: W
authors.lastname: Brinjikji
authors.forename: H
authors.initials: H
authors.lastname: Cloft
authors.forename: G
authors.initials: G
authors.lastname: Lanzino
authors.forename: D F
authors.initials: DF
authors.lastname: Kallmes
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D002533:Cerebral Angiography; D002536:Cerebral Arteries / Q000000981:diagnostic imaging / Q000473:pathology; D004621:Embolization, Therapeutic; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D055815:Young Adult