title: Diagnostic value of time-resolved CT angiography for the lower leg.
abstract: OBJECTIVE
  The aim of this study was to test the feasibility of time-resolved computed tomography angiography (TR-CTA) for use in the lower leg.
  
  
  METHODS
  Fifty-nine patients with suspected peripheral arterial occlusive disease were examined with a standard CTA (S-CTA) of the lower run-off and with an additional TR-CTA of the calves (12 phases; 2.5 s/phase, 80 kV, 120 mAs, volume of contrast medium 50 mL, flow rate 5.0 mL/s). For seven lower-leg artery segments, arterial contrast and the presence of venous overlay were tested for S-CTA and TR-CTA. Stenoses were classified on a three-point scale separately for S-CTA and TR-CTA, and diagnostic confidence for stenosis assessment was evaluated for both datasets. Contrast arrival times and HU values were evaluated in patients with asymmetric proximal stenoses.
  
  
  RESULTS
  TR-CTA resulted in significantly higher contrast enhancement (P < 0.0001) and less venous overlay as compared to S-CTA (P < 0.05). Diagnostic confidence for stenosis rating was significantly higher in TR-CTA (P < 0.0001). Asymmetric proximal stenoses lead to significantly delayed and diminished contrast enhancement on the stenotic side.
  
  
  CONCLUSIONS
  TR-CTA of the calves is feasible and provides higher enhancement and higher diagnostic confidence as compared to monophasic CTA of the lower legs.
authors.affiliation: Department of Clinical Radiology, University Hospital-Grosshadern, Ludwig-Maximilians University, Munich, Munich, Germany. wieland.sommer@med.uni-muenchen.de
authors.forename: Wieland H
authors.initials: WH
authors.lastname: Sommer
authors.forename: Andreas
authors.initials: A
authors.lastname: Helck
authors.forename: Fabian
authors.initials: F
authors.lastname: Bamberg
authors.forename: Edda
authors.initials: E
authors.lastname: Albrecht
authors.forename: Christoph R
authors.initials: CR
authors.lastname: Becker
authors.forename: Rolf
authors.initials: R
authors.lastname: Weidenhagen
authors.forename: Harald
authors.initials: H
authors.lastname: Kramer
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*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000033:anatomy & histology* / Q000098:blood supply*; D008297:Male; D058729:Peripheral Arterial Disease / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*