Diagnostic Accuracy of Computerized Impedance Plethysmography in the Diagnosis of Symptomatic Deep Vein Thrombosis: A Controlled Venographic Study

Abstract

The aim of our study was to evaluate the sensitivity, the specificity, and the positive and negative predictive values of a recently developed computerized impedance plethysmography (CIP) in the diagnosis of deep vein thrombosis (DVT); 117 consecutive outpatients with a clinical suspicion of DVT were evaluated. After informed consent was obtained, a CIP and, within twenty-four hours, a venography of the symptomatic lower limb were performed in each patient. The results of CIP were compared with the results of contrast venography, which was considered as the gold standard. As far as the diagnosis of both proximal and distal DVT was concerned, the accuracy of CIP was 88.5%; the sensitivity and specificity were 95.1% and 83.6%, respectively; the positive and negative predictive values were 81.2% and 95.8%, respectively. When the diagnosis of only proximal deep vein thrombosis was considered, the accuracy of CIP was 88.8%; the sensitivity and specificity were 97.1% and 83.6%, respectively; the positive and negative predictive values were 79.0% and 97.8%, respectively. The authors conclude that the newly developed CIP has a diagnostic accuracy similar to that of traditional impedance plethysmography. Moreover, being completely automated and portable, CIP can play an important role in the bedside diagnosis of DVT.