title: Imaging of deep vein thrombosis.
abstract: BACKGROUND
  Deep vein thrombosis of the leg affects 1-2 per cent of the population with an annual incidence of 0.5-1 per 1000. It presents with non-specific symptoms and signs making clinical diagnosis difficult. Techniques to image and diagnose this condition are advancing rapidly.
  
  
  RESULTS
  A literature review from 1980 to 2007 was undertaken using PubMed, The Cochrane Library, Medline and Embase. The most frequently used diagnostic test is duplex ultrasonography which is accurate above the knee and has a low cost, but is limited by inaccuracy when assessing the pelvic and distal veins and in diagnosing a new thrombosis in the post-thrombotic limb. Magnetic resonance imaging (MRI) and sonographic elasticity imaging are more recent techniques that have shown promise in overcoming these limitations. However, their availability is currently restricted because they are expensive. Computed tomography (CT) is sensitive, specific and provides good imaging of the pelvis. It has the advantage that it can be performed at the same time as CT pulmonary angiography.
  
  
  CONCLUSIONS
  MRI has some specific advantages over duplex ultrasonography, but requires refinement before it can be used clinically. Venography or CT venography should be considered when duplex scanning is inadequate.
authors.affiliation: King's College London, Academic Department of Surgery, Cardiovascular Division, St Thomas' Hospital, London, UK.
authors.forename: J H
authors.initials: JH
authors.lastname: Orbell
authors.forename: A
authors.initials: A
authors.lastname: Smith
authors.forename: K G
authors.initials: KG
authors.lastname: Burnand
authors.forename: M
authors.initials: M
authors.lastname: Waltham
mesh_terms: D003952:Diagnostic Imaging / Q000379:methods*; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods; D010690:Phlebography / Q000379:methods; D012008:Recurrence; D014057:Tomography, X-Ray Computed / Q000379:methods; D020246:Venous Thrombosis / Q000175:diagnosis*