Evaluation of diagnostic reliability of radionuclide phlebography using 99mTc-MAA to detect deep venous thrombosis; its role in establishing indications for inferior vena cava filter implantation.

Radionuclide phlebography (RNP) of the lower extremities and pelvis was performed using 99mTc-MAA in 40 patients with pulmonary thromboembolism. Deep venous thrombosis (DVT) was found in all patients, more frequently in the right calf and in the left iliac veins in 20 patients (55%). RNP and contrast phlebography (CP) were performed in 18 patients and confirmed the presence of DVT in all cases. The greatest specificity of RNP was obtained in the left (92.4%) and in the right pelvis (80%). In 12 of 18 patients in whom a cava filter was implanted, specificity of RNP was 100% for the left thigh and 91.7% for other localizations. In establishing indications for cava filter implantation, RNP should be performed prior to CP and bilaterally, but in case of non-indicated CP, RNP findings should be sufficient.