title: Preoperative planning for endovascular aortic repair of abdominal aortic aneurysms: feasibility of nonenhanced MR angiography versus contrast-enhanced CT angiography.
abstract: OBJECTIVE
  To compare vascular measurements to determine stent types and configurations for abdominal endovascular aneurysm repair (EVAR) by comparing results of contrast material-enhanced computed tomographic (CT) angiography and nonenhanced magnetic resonance (MR) angiography.
  
  
  METHODS
  This prospective study was institutional review board approved, and all patients provided written informed consent. Fifty patients (45 men and five women; mean age, 76.0 years) admitted for elective abdominal EVAR underwent preoperative abdominal CT angiography (triplanar reformatted images; section thickness of 1-3 mm) and nonenhanced MR angiography (triplanar two-dimensional single-shot turbo field-echo images; section thickness of 6 mm). Two observers independently completed standard measurement and device selection forms for endovascular stent planning for CT and MR angiography. Pearson and intraclass correlation coefficients were calculated to evaluate intermodality and interobserver differences.
  
  
  RESULTS
  No significant difference was found in aortic neck diameter (observer 1: CT, 18.5 mm; MR, 19.0 mm; P = .43) (observer 2: CT, 19.6 mm; MR, 19.3 mm; P = .59), aortic neck diameter 15 mm distal to the lowest renal artery (observer 1: CT, 19.2 mm; MR, 19.2 mm; P = .38) (observer 2: CT, 19.6 mm; MR, 19.6 mm; P = .91), aortic neck length (observer 1: CT, 43.6 mm; MR, 43.6 mm; P = .85) (observer 2: CT, 44.4 mm; MR, 44.0 mm; P = .93), or other key vascular measurements (P = .23-.99) for preoperative planning. These included aneurysm diameter, lowest renal artery to aortic bifurcation length, aortic bifurcation diameter, common iliac artery diameters, external iliac artery diameters, length between orifices of lower renal and internal iliac arteries, and iliac artery sealing length. CT and MR angiography measurements showed very strong correlation (r = 0.92-0.99). Intraclass correlation coefficients between observers ranged from 0.90 to 0.98. Stent types and configurations determined with CT measurements remained unaltered when reassessed with MR measurements.
  
  
  CONCLUSIONS
  Measurements obtained with nonenhanced MR angiography appear equally accurate to those of CT angiography in the preoperative planning of abdominal EVAR.
authors: Department of Radiology, Gifu University Hospital, 1-1 Yanagido, Gifu 501-1194, Japan. gossy@par.odn.ne.jp
authors: Satoshi
authors: S
authors: Goshima
authors: Masayuki
authors: M
authors: Kanematsu
authors: Hiroshi
authors: H
authors: Kondo
authors: Hiroshi
authors: H
authors: Kawada
authors: Toshihisa
authors: T
authors: Kojima
authors: Kota
authors: K
authors: Sakurai
authors: Haruo
authors: H
authors: Watanabe
authors: Katsuya
authors: K
authors: Shimabukuro
authors: Yukihiro
authors: Y
authors: Matsuno
authors: Narihiro
authors: N
authors: Ishida
authors: Hirofumi
authors: H
authors: Takemura
authors: Kyongtae T
authors: KT
authors: Bae
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D003287:Contrast Media; D057510:Endovascular Procedures; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D011446:Prospective Studies; D015607:Stents; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media