title: Spiral CT of renal artery stenosis: comparison of three-dimensional rendering techniques.
abstract: OBJECTIVE
  To evaluate the accuracy of computed tomographic (CT) angiography in the detection of renal artery stenosis (RAS).
  
  
  METHODS
  CT angiography was performed in 31 patients undergoing conventional renal arteriography. CT angiographic data were reconstructed with shaded surface display (SSD) and maximum-intensity projection (MIP). Stenosis was graded with a four-point scale (grades 0-3). The presence of mural calcification, poststenotic dilatation, and nephrographic abnormalities was also noted.
  
  
  RESULTS
  CT angiography depicted all main (n = 62) and accessory (n = 11) renal arteries that were seen at conventional arteriography. MIP CT angiography was 92% sensitive and 83% specific for the detection of grade 2-3 stenoses (> or = 70% stenosis). SSD CT angiography was 59% sensitive and 82% specific for the detection of grade 2-3 stenoses. The accuracy of stenosis grading was 80% with MIP and 55% with SSD CT angiography. Poststenotic dilatation and the presence of an abnormal nephrogram were 85% and 98% specific, respectively.
  
  
  CONCLUSIONS
  CT angiography shows promise in the diagnosis of RAS. The accuracy of CT angiography varies with the three-dimensional rendering technique employed.
authors.affiliation: Department of Radiology, Stanford University Hospital and Medical Center, CA 94305-5105.
authors.forename: G D
authors.initials: GD
authors.lastname: Rubin
authors.forename: M D
authors.initials: MD
authors.lastname: Dake
authors.forename: S
authors.initials: S
authors.lastname: Napel
authors.forename: R B
authors.initials: RB
authors.lastname: Jeffrey
authors.forename: C H
authors.initials: CH
authors.lastname: McDonnell
authors.forename: F G
authors.initials: FG
authors.lastname: Sommer
authors.forename: L
authors.initials: L
authors.lastname: Wexler
authors.forename: D M
authors.initials: DM
authors.lastname: Williams
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007668:Kidney / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012077:Renal Artery / Q000000981:diagnostic imaging; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed