title: Duplex ultrasound scanning of peripheral arterial disease of the lower limb.
abstract: OBJECTIVE
  To assess the reliability and applicability of duplex ultrasound scanning (DUS) of lower limb arteries, compared with digital subtraction angiography (DSA), in patients with peripheral arterial disease (PAD).
  
  
  METHODS
  A prospective, blinded, comparative study.
  
  
  METHODS
  A total of 169 patients were examined by DUS and DSA. Intermittent claudication (IC) was present in 42 (25%) patients and critical limb ischaemia (CLI) in 127 (75%) patients. To allow segment-to-segment comparison, the arterial tree was divided into 15 segments. In total, 2535 segments were examined using kappa (κ) statistics to test the agreement.
  
  
  RESULTS
  The agreement between DUS and DSA was very good (κ>0.8) or good (0.8 ≥ κ>0.6) in most segments, but moderate (0.6 ≥ κ>0.4) in the tibio-peroneal trunk and the peroneal artery. Agreement between the two techniques was significantly better in the supragenicular (κ=0.75 (95% confidence interval (CI): 0.70-0.80)) than in the infragenicular segments (κ=0.63 (0.59-0.67)) (p<0.001). Similarly, the technical success rate was significantly higher in the supragenicular segments (DUS: 100%; DSA: 99%) than in the infragenicular segments (both 93%) (p<0.001). DUS was the best technique for imaging of the distal crural arteries (92% vs. 97%; p<0.001) and DSA was the best technique for imaging of the proximal crural arteries (95% vs. 91%; p<0.01). Neither the agreement nor the technical success rate was influenced by the severity of PAD, that is, IC versus CLI.
  
  
  CONCLUSIONS
  The agreement between DUS and DSA was generally good, irrespective of the severity of ischaemia. DUS performed better in the supragenicular arteries than in the infragenicular arteries. However, DUS compared favourably with DSA in both tibial vessels, particularly in the distal part, which makes DUS a useful non-invasive alternative to DSA.
authors.affiliation: Department of Vascular Surgery, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark. jonas@eiberg.org
authors.forename: J P
authors.initials: JP
authors.lastname: Eiberg
authors.forename: J B
authors.initials: JB
authors.lastname: Grønvall Rasmussen
authors.forename: M A
authors.initials: MA
authors.lastname: Hansen
authors.forename: T V
authors.initials: TV
authors.lastname: Schroeder
mesh_terms: D000368:Aged; D015901:Angiography, Digital Subtraction; D055109:Ankle Brachial Index; D016001:Confidence Intervals; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000098:blood supply* / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018616:Ultrasonography, Doppler, Duplex / Q000379:methods*