title: Distribution of thrombi in acute lower extremity deep venous thrombosis: implications for sonography and CT and MR venography.
abstract: OBJECTIVE
  Our objective was to determine the typical distribution of thrombi in acute lower extremity deep venous thrombosis as a means of evaluating the validity of imaging techniques that only include the common femoral and popliteal veins, but not the superficial femoral vein.
  
  
  METHODS
  The results of 2704 lower extremity venous sonograms, obtained in 2026 consecutive patients over a 4-year interval, were reviewed retrospectively. The distribution of acute deep venous thromboses across various lower extremity venous segments was analyzed for this population, which consisted of both symptomatic and asymptomatic patients.
  
  
  RESULTS
  Of 2704 lower extremities studied with duplex sonography, acute deep venous thrombosis was identified in 269 (9.9%). Of these 269 cases, acute deep venous thrombosis was isolated to the superficial femoral vein in 60 (22.3%). The remaining 209 cases (77.7%) showed thrombus that extended into the common femoral or popliteal veins (or both).
  
  
  CONCLUSIONS
  An abbreviated imaging study that evaluates only the common femoral and popliteal veins would fail to identify more than 20% of lower extremity acute deep venous thromboses in a population like ours. Although evaluation of the superficial femoral vein requires additional time and resources, evaluation of this segment may prevent a substantial number of thrombi from being missed.
authors.affiliation: Department of Radiology, University of Pennsylvania Medical Center, Hospital of the University of Pennsylvania, 3400 Spruce St., Philadelphia, PA 19104, USA.
authors.forename: D D
authors.initials: DD
authors.lastname: Maki
authors.forename: N
authors.initials: N
authors.lastname: Kumar
authors.forename: B
authors.initials: B
authors.lastname: Nguyen
authors.forename: J E
authors.initials: JE
authors.lastname: Langer
authors.forename: W T
authors.initials: WT
authors.lastname: Miller
authors.forename: W B
authors.initials: WB
authors.lastname: Gefter
mesh_terms: D000208:Acute Disease; D005268:Femoral Vein / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D007866:Leg / Q000098:blood supply*; D018810:Magnetic Resonance Angiography; D011152:Popliteal Vein / Q000000981:diagnostic imaging / Q000473:pathology; D012039:Regional Blood Flow / Q000502:physiology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D018616:Ultrasonography, Doppler, Duplex; D020246:Venous Thrombosis / Q000175:diagnosis*