The diagnostic approach to deep venous thrombosis

Accurate diagnosis of deep vein thrombosis is important because untreated d eep vein thrombosis can cause death or permanent impairment and because eff ective treatments are available. The approach to the diagnosis of deep vein thrombosis varies because of differences in local resources and expertise. Duplex ultrasonography with venous compression is the preferred initial te st for the majority of outpatients who present with symptoms and signs that suggest acute deep vein thrombosis. Clinical outcome studies have shown th e safety of withholding anticoagulants when two compression ultrasonography examinations are negative over a 5- to 7-day period. Alternative strategie s, for example, combining clinical scores and D-dimer with compression ultr asonography, may also prove effective. In unusual circumstances, venography or even magnetic resonance imaging may be necessary.