title: Vessel wall calcifications at multi-detector row CT angiography in patients with peripheral arterial disease: effect on clinical utility and clinical predictors.
abstract: OBJECTIVE
  To evaluate retrospectively the effect of vessel wall calcifications on the clinical utility of multi-detector row computed tomographic (CT) angiography performed in patients with peripheral arterial disease and to identify clinical predictors for the presence of vessel wall calcifications.
  
  
  METHODS
  The study was approved by the hospital institutional review board, and informed consent was obtained from all patients. For this study the authors included patients from two randomized controlled trials that measured the costs and effects of diagnostic imaging in patients with peripheral arterial disease. All patients underwent CT angiography and were followed up for 6 months. Clinical utility was measured on the basis of therapeutic confidence (rated on a 10-point scale) in the results of initial CT angiography and the need for additional vascular imaging. Univariable and multivariable logistic and linear regression analysis and the area under the receiver operating characteristic curve were used to evaluate the effect of vessel wall calcifications on the clinical utility of CT angiography and the use of patient characteristics to predict the number of calcified segments at CT angiography.
  
  
  RESULTS
  A total of 145 patients were included (mean age, 64 years; 70% men). The authors found that the number of calcified segments was a significant predictor of the need for additional imaging (P = .001) and of the confidence scores (P < .001). The number of calcified segments discriminated between patients who required additional imaging after CT angiography and those who did not (area under the receiver operating characteristic curve, 0.66; 95% confidence interval: 0.54, 0.77). Age, diabetes mellitus, and cardiac disease were significant predictors of the number of calcified segments in both the univariable and multivariable analyses (P < .05).
  
  
  CONCLUSIONS
  Vessel wall calcifications decrease the clinical utility of CT angiography in patients with peripheral arterial disease. Diabetes mellitus, cardiac disease, and elderly age (older than 84 years) are independently predictive for the presence of vessel wall calcifications.
authors.affiliation: Program for the Assessment of Radiological Technology and the Department of Radiology, Erasmus MC Rotterdam, Dr Molewaterplein 50, Room Ee 21-40a, 3015 GE Rotterdam, the Netherlands.
authors.forename: Rody
authors.initials: R
authors.lastname: Ouwendijk
authors.forename: Marc C J M
authors.initials: MC
authors.lastname: Kock
authors.forename: Lukas C
authors.initials: LC
authors.lastname: van Dijk
authors.forename: Marc R H M
authors.initials: MR
authors.lastname: van Sambeek
authors.forename: Theo
authors.initials: T
authors.lastname: Stijnen
authors.forename: M G Myriam
authors.initials: MG
authors.lastname: Hunink
mesh_terms: D015901:Angiography, Digital Subtraction / Q000379:methods*; D002114:Calcinosis / Q000000981:diagnostic imaging*; D003365:Costs and Cost Analysis; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000000981:diagnostic imaging*; D012372:ROC Curve; D012044:Regression Analysis; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed