Accuracy of magnetic resonance imaging in the diagnosis of deep vein thrombosis in asymptomatic patients with injuries of the lower extremity a pilotstudy

This is a prospective comparative study of magnetic resonance imaging (MRI) of the deep veins versus contrast venography in consecutive patients treat ed for various injuries to their lower extremities, showing no clinical sym ptoms of deep vein thrombosis. The majority of examinations referred to in this study were performed according to the following methodology: First, th e patient was subjected to MRI. Subsequently, within a 24-h interval, he/sh e was subjected to contrast venography. The acquired results were compared in a blinded manner. The diagnostic indices for MRI were calculated on the assumption that the results of contrast venography were sure to give an acc urate indication of either presence or absence of thrombosis. Thirty-six pa tients were included in the study, of which 27 (15 males) completed it. The overall incidence of distal deep venous thrombosis (DVT) was 22% (6/27). O ne patient showed extension of a crural thrombus into the popliteal vein. M RI did not detect any of the thrombi. This lack of result was ascribed to f ailure to fully demonstrate all segments of the crural veins. However, MRI did show three proximal thrombi in the superficial femoral vein, which were not shown by the venograms. Thus, both the sensitivity and specificity of MRI were 0%, so MRI proved to be of no value in the diagnosis of asymptomat ic deep venous thrombosis in this study. (C) 2001 Elsevier Science Ltd. All rights reserved.