title: Diagnostic accuracy of dynamic computed tomographic angiographic of the lower leg in patients with critical limb ischemia.
abstract: OBJECTIVE
  The purpose of this study was to assess the diagnostic accuracy of dynamic computed tomographic angiography (dyn-CTA) in patients with critical lower leg ischemia.
  
  
  METHODS
  A population of 29 patients with known peripheral arterial occlusive disease (Fontaine stage III or IV) was examined with a combined CTA protocol consisting of a standard CTA (s-CTA) of the lower leg runoff from the diaphragm to the toes and dyn-CTA of the calves (scan range, 48 cm; 8 phases; 3.5 seconds per phase, 100 kV; 120 mAs; contrast volume, 50 mL; flow rate, 5.0 mL/s). Digital subtraction angiography was performed on all patients and served as a reference standard. For each of seven lower leg artery segments, arterial contrast and diagnostic confidence for stenosis assessment (3-point scale) were tested for s-CTA and dyn-CTA. Similarly, stenoses of calf-segments were classified on a 3-point scale separately for s-CTA and dyn-CTA and were compared with digital subtraction angiography to assess diagnostic accuracy.
  
  
  RESULTS
  Compared with s-CTA, dyn-CTA resulted in significantly higher arterial contrast enhancement (68% vs 46% optimal contrast; P < 0.01) and higher diagnostic confidence (64% vs 48% fully confident, respectively, P < 0.05). Dyn-CTA had a slightly higher sensitivity for the detection of significant stenosis (98.0% vs 96.6%), and for the detection of occlusion (95.4% vs 94.4%). Specificity for dyn-CTA was higher than for s-CTA, both for detection of stenosis (97.1% vs 92.2%) and especially for the detection of vessel occlusions (99.3% vs 94.4%; P < 0.05).
  
  
  CONCLUSIONS
  Compared with s-CTA, dyn-CTA provides improved arterial contrast enhancement, higher diagnostic confidence, and increased diagnostic accuracy for the detection of stenoses and occlusions in peripheral arterial occlusive disease patients.
authors.affiliation: Department of Clinical Radiology, University Hospitals-Grosshadern, Ludwig-Maximilians University, Munich, Germany. wieland.sommer@med.uni-muenchen.de
authors.forename: Wieland H
authors.initials: WH
authors.lastname: Sommer
authors.forename: Fabian
authors.initials: F
authors.lastname: Bamberg
authors.forename: Thorsten R C
authors.initials: TR
authors.lastname: Johnson
authors.forename: Rolf
authors.initials: R
authors.lastname: Weidenhagen
authors.forename: Mike
authors.initials: M
authors.lastname: Notohamiprodjo
authors.forename: Florian
authors.initials: F
authors.lastname: Schwarz
authors.forename: Maximilian F
authors.initials: MF
authors.lastname: Reiser
authors.forename: Konstantin
authors.initials: K
authors.lastname: Nikolaou
mesh_terms: D000368:Aged; D000792:Angiography / Q000379:methods*; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007511:Ischemia / Q000000981:diagnostic imaging*; D007866:Leg / Q000098:blood supply* / Q000000981:diagnostic imaging*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*