title: Agreement of duplex ultrasonography vs. computed tomography angiography for evaluation of native and in-stent SFA re-stenosis--findings from a randomized controlled trial.
abstract: BACKGROUND
  Multidetector CT angiography (CTA) is a non-invasive imaging technique for evaluation of peripheral vascular disease. CTA might be particularly useful for assessment of intermediate- and long-term morphological outcome after endovascular treatment. Validation of CTA vs. the current imaging standard, colour Doppler ultrasonography (CDUS), for quantification of native and in-stent re-stenosis in the superficial femoral artery (SFA) is required.
  
  
  METHODS
  Seventy randomized patients who underwent stent implantation (n=47) or balloon angioplasty (n=23) underwent 6-month follow-up with CDUS and CTA. CTA was compared with CDUS in both sub-groups of patients in terms of binary re-stenosis (>50% lumen narrowing) and re-occlusion. Agreement between CTA and CDUS was assessed using Kappa (κ) statistics with 95% confidence intervals, and correlation coefficients.
  
  
  RESULTS
  Binary re-stenosis was detected in 16/70 (22.9%) patients by CTA and 17/70 (24.3%) patients by CDUS (κ=0.88, 95% CI: 0.80-0.96). Re-stenosis rates after balloon angioplasty were 39.1% (9/23) on CTA and CDUS (κ=0.82, 95% CI: 0.66-0.98), and after stent implantation 14.9% (7/47) on CTA and 17.0% (8/47) on CDUS (κ=0.92, 95% CI: 0.84-1.00). Re-occlusions were detected in 3/70 (4.3%) patients by both CTA and CDUS (κ=0.65; 95% CI 0.54-0.76). Significant correlations (r=0.85, p<0.001) were noted between degree of re-stenosis on CTA and peak velocity ratio on CDUS. The correlation coefficient was higher in patients after balloon angioplasty (r=0.94, p<0.001) than in patients after stent implantation (r=0.71, p<0.001).
  
  
  CONCLUSIONS
  CTA and CDUS show excellent agreement for evaluation of native and in-stent re-stenosis after endovascular treatment of SFA obstructions. CTA is an appropriate non-invasive imaging modality for follow-up after endovascular therapy.
authors.affiliation: Department of Cardiovascular and Interventional Radiology, Medical University, Vienna, Austria. herbert.langenberger@meduniwien.ac.at
authors.forename: Herbert
authors.initials: H
authors.lastname: Langenberger
authors.forename: Martin
authors.initials: M
authors.lastname: Schillinger
authors.forename: Christina
authors.initials: C
authors.lastname: Plank
authors.forename: Schila
authors.initials: S
authors.lastname: Sabeti
authors.forename: Petra
authors.initials: P
authors.lastname: Dick
authors.forename: Manfred
authors.initials: M
authors.lastname: Cejna
authors.forename: Johannes
authors.initials: J
authors.lastname: Lammer
authors.forename: Erich
authors.initials: E
authors.lastname: Minar
authors.forename: Christian
authors.initials: C
authors.lastname: Loewe
mesh_terms: D000368:Aged; D000792:Angiography / Q000379:methods*; D005260:Female; D005263:Femoral Artery / Q000000981:diagnostic imaging* / Q000601:surgery*; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging* / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015607:Stents / Q000009:adverse effects*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014463:Ultrasonography / Q000379:methods*