TRIPLEX US IN THE DIAGNOSIS OF ASYMPTOMATIC DEEP VENOUS THROMBOSIS

Purpose: To evaluate the accuracy of tripler ultrasound (TUS) compared with venography as a screening test for deep venous thrombosis (DVT), and to evaluate interobserver variation in the interpretation of the venographic studies. Material and Methods: A total of 133 postoperativ e hip fracture patients, asymptomatic of DVT, were prospectively exami ned with TUS and venography. All venograms were reviewed blindly and i n case of disagreement a consensus was arrived at. Results: The incide nce of DVT was 20%, with isolated calf vein thrombi in 63% of the case s. There were 7 false-negative and one false-positive result/s at TUS, with a sensitivity of 74%, specificity of 99% and accuracy of 97%. Th e kappa values ranged from 0.58 to 0.82. The false-negative results we re all caused by missed calf vein thrombi in technically inadequate ex aminations. At sonography 2% of vein segments were noninterpretable, c ompared to 29% at venography.Conclusion: Venous US is less sensitive a s a test for DVT in this study of asymptomatic patients than in earlie r studies on symptomatic patients. Still, sonographic screening of hig h-risk patients would be both effective and cost effective. Fresh thro mbi may cause a false-negative compression test.