title: Multidetector CT angiography in the follow-up of patients treated with renal artery stents: value of different reformation techniques compared with axial source images.
abstract: OBJECTIVE
  To evaluate the role of 4 different reformation techniques in comparison with axial images from multidetector computed tomographic angiography (MDCTA) in the follow-up of renal artery stents.
  
  
  METHODS
  Data on 40 patients (20 men; mean age 65 years) who underwent MDCTA as part of their routine follow-up after successful primary stenting of a main renal artery were retrospectively analyzed. Multiplanar reformation (MPR), curved planar reformation (CPR), volume rendering threshold (VRT), and virtual angioscopy (VA) were reviewed by 2 independent observers who were blinded to the results of the axial source images, which served as the gold standard. The stenosis degree was scored as I = 0%, II <50%, III = 51%-75%, IV = 76%-99%, or V = occlusion; a stenosis >50% was considered hemodynamically significant.
  
  
  RESULTS
  Five hemodynamically significant stenoses were identified on axial images. The correlation with axial images was perfect for both observers using MPR and CPR (kappa = 1 for each observer); corresponding results were kappa = 0.69 and kappa = 0.64 for VRT and kappa = 0.88 and kappa = 0.83 for VA, respectively. The interobserver correlations were excellent for all reformation techniques (kappa = 0.95 to 1).
  
  
  CONCLUSIONS
  Compared to axial images, MPR and CPR correlated perfectly with axial images; VA performed surprisingly well, while VRT was affected by artifacts and consequently showed inferior results.
authors.affiliation: Department of Cardiovascular and Interventional Radiology, Medical University Vienna, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Puchner
authors.forename: Alfred
authors.initials: A
authors.lastname: Stadler
authors.forename: Erich
authors.initials: E
authors.lastname: Minar
authors.forename: Johannes
authors.initials: J
authors.lastname: Lammer
authors.forename: Robert A
authors.initials: RA
authors.lastname: Bucek
mesh_terms: D000368:Aged; D000792:Angiography / Q000295:instrumentation; D000800:Angioplasty, Balloon; D016477:Artifacts; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D012077:Renal Artery / Q000000981:diagnostic imaging*; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging* / Q000628:therapy; D015203:Reproducibility of Results; D012107:Research Design; D012189:Retrospective Studies; D012720:Severity of Illness Index; D015607:Stents; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*; D016896:Treatment Outcome; D014584:User-Computer Interface