Plain Computed Tomographic Examination for Diagnosis of Acute Deep Vein Thrombosis

Abstract

We investigated the diagnostic efficacy of computed tomography (CT) for proximal deep vein thrombosis (DVT). The ratio of femoral/crural muscle swelling (affected/unaffected) was estimated by determining the femoral/crural muscle area on CT scans (FMR: femoral muscle ratio, CMR: crural muscle ratio). This examination is quick and safe and provides an easy access tool for evaluating patients with limb swelling, it is suitable especially for primary care physicians. The aim of the present study was to establish the threshold for screening proximal DVT and determine the diagnostic efficacy of CT for distal DVT. The FMR threshold for proximal DVT was 1.2; sensitivity, specificity, accuracy, and predictive value of this test were 80%, 100%, 85% and 100%, respectively. The CMR threshold for distal DVT was 1.15; sensitivity, specificity, accuracy, and predictive value of this test were 83%, 80%, 81% and 71%, respectively. Thus, we propose use of the FMR/CMR as a strategy for diagnosis of DVT in Japan.