title: Prediction of the presence of renal artery stenosis by calcium scoring of the abdominal aorta.
abstract: OBJECTIVE
  To establish a method for estimating the probability of renal artery stenosis (RAS) based on the calcium volume score of the aorta (ACS).
  
  
  METHODS
  In a retrospective observation study, CT angiographies acquired on a 64-slice MDCT scanner were analyzed for 1351 patients (female: 531; male 826; mean age 60.9 ± 17.7 years). A volumetric scoring method was used, detecting plaques with a density of more than 600 HU.
  
  
  RESULTS
  13.8% of the patients showed a stenosis >50%, 4.1% a stenosis >70%. The ACS was 0.61 ± 1.01 ml calcium. The sensitivity for detection of RAS >50% and RAS >80% was 0.9572 and 1.0, respectively. The negative predictive value (NPV) of a lack of calcification for excluding RAS >50% and RAS >80% was 0.9752 and 1, respectively. As ACS increased, the specificity for RAS >50% increased to 0.9390. With an ACS of 0.380 ml, accuracy reached a maximum of 0.6585. ROC analyses yielded an area under the curve of 0.88 (p<0.0001). Sensitivity, specificity, NPV and PPV are indicated in relation to the degree of RAS, as well as the diagnostic yield of the method, which is valuable in patients older than 50 years.
  
  
  CONCLUSIONS
  Due to its extremely high sensitivity and NPV, the ACS is a very useful screening method for RAS. The validity of the method, as well as its diagnostic value is equivalent to that of coronary artery calcium scoring. Lack of calcifications of the aorta renders atherosclerotic RAS highly improbable.
authors: Department of Radiology, Innsbruck Medical University, Anichstrasse 35, 6020 Innsbruck, Austria. bernhard.glodny@i-med.ac.at
authors: Bernhard
authors: B
authors: Glodny
authors: Parinaz
authors: P
authors: Nasseri
authors: Michaela
authors: M
authors: Plaikner
authors: Verena
authors: V
authors: Unterholzner
authors: Peter
authors: P
authors: Rehder
authors: Christian
authors: C
authors: Koppelstätter
authors: Johannes
authors: J
authors: Petersen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods*; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging* / Q000473:pathology; D001018:Aortic Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D002114:Calcinosis / Q000000981:diagnostic imaging* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D011857:Radiographic Image Interpretation, Computer-Assisted; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging* / Q000473:pathology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*