Abstract
Radionuclide venography in two patients with suspected deep venous disease revealed double channel drainage with cross-pelvic collateral circulation. Contrast inferior venacavograms revealed that one patient had persistent right and left supracardinal veins (double inferior vena cava) and the other had iliac vein occlusion with ascending lumbar collateral circulation. The similarity of radionuclide venographic findings in these two patients emphasizes the importance of contrast venacavography in patients with this appearance on radionuclide venography.