Unusual causes of varicose veins in the lower extremities: CT venographic and Doppler US findings.

There are various causes of varicose veins in the lower extremities. Among the causes are venous insufficiency of the saphenofemoral junction, saphenopopliteal junction, or usual perforating veins. Traditionally, Doppler ultrasonography (US) has been used for evaluation of varicose veins. Sometimes, varicose veins arise from an unexpected anatomic source; in these cases, computed tomographic (CT) venography can provide an overview of the varicose veins. Doppler US with complementary CT venography is useful for determining the precise cause of varicose veins. Between November 2003 and March 2008, the authors evaluated 1350 cases of varicose veins in the lower extremities with both CT venography and Doppler US. The varicose veins were classified according to their causes; unusual causes were studied and included vulvoperineal varicosity, intraosseous perforating vein incompetence, round ligament varicosity, persistent sciatic vein incompetence, Klippel-Trenaunay syndrome, and portosystemic collateral pathways. Radiologists should be familiar with the complete range of primary causes of varicose veins in the lower extremities and with their radiologic manifestations and should recognize the complementary role of CT venography in their evaluation.