Diagnosis of pulmonary embolism by 64-detector MDCT combined with doppler ultrasonography and indirect CTV of the leg: A different protocol

Abstract

The aim of our study was to investigate the contribution of CT angiography in cases with a presumptive PTE diagnosis, evaluating lower extremity veins with CT venography and color Doppler ultrasonography (CDU) and the role of these methods at diagnosis of DVT. 46 patients with presumptive diagnosis of PTE which was confirmed with a positive CT angiography (CTA) were included in the study. Lower extremities between the iliac crest and head of femur and the popliteal region were scanned having 17-18 slices from each area, without administring extra contrast medium with a 0.8 mm slice gap. The patients underwent lower extremity CDU on the same day. Four out of 46 patients were shown to have thrombus by CDU while their CTV were normal. Two of them had an appearance of thrombus on CTV while their CDU were normal. When we consider CDU as the gold standard method, the sensitivity of CTV is calculated as 81.8% and the specificity as 91.6%. Kappa value between two modalities was calculated as 0.738 and a consistency of 87% is found. Mean radiation dose was calculated as 2.43 mSv for CTA and 0.457 mSv for CTV. With the imaging technique so-called combined CTA-indirect CTV method, DVT can be determined with moderate sensitivity and high specificity with application of low dose extra radiation.