Non-invasive detection of deep venous thrombosis: ultrasonography versus duplex scanning.

In a prospective study the diagnostic value of compression ultrasonography (CUS) versus Duplex scanning (DS) in the non-invasive detection of acute femoropopliteal deep venous thrombosis (DVT) was determined. In 114 eligible patients clinically suspected of DVT of the lower extremity, compression ultrasonography and Duplex scanning were performed within 24 hours by different assessors unaware of the outcome of the other test. In 109 patients concordant results of combined compression ultrasonography and Duplex scanning were obtained and considered as a proof of the absence or presence of deep venous thrombosis and no subsequent invasive investigations were performed. In five patients compression ultrasonography and Duplex scanning were discordant and contrast venography was performed. Femoropopliteal thrombosis was present in 47 legs (41%). The sensitivity, specificity and accuracy of compression ultrasonography were 93.6, 97.0 and 95.6%, respectively, and of Duplex scanning 100, 98.5 and 99.1%, respectively. We conclude that compression ultrasonography and Duplex scanning are methods with comparably high accuracy. Because of its availability, accuracy, cost-effectiveness and simplicity we recommend compression ultrasonography as the primary diagnostic test in the detection of deep venous thrombosis.