Chronic-stage deep vein thrombosis of the lower extremities: indirect CT venographic findings

OBJECTIVE: To describe the computed tomographic (CT) findings of chronic deep vein thrombosis (DVT) and its evolution from acute DVT. METHODS: Fifty-one consecutive patients with 52 legs confirmed as acute DVT by CT venography underwent follow-up computed tomography more than 2 months later. Follow-up CT findings were assessed retrospectively by consensus between 2 radiologists. The frequencies of CT findings were analyzed for affected venous segments: common iliac, external iliac, femoral, popliteal, and calf veins. RESULTS: Twelve legs (23%) were completely normalized on follow-up computed tomography, but 40 legs (77%) showed abnormal findings as follows: luminal obliteration (n = 16), decreased caliber (n = 30), residual thrombi (n = 3), fibrotic bands (n = 28), ipsilateral muscle enlargement (n = 28), ipsilateral subcutaneous edema (n = 11), and superficial collateral vein development (n = 23). The external iliac vein (26/40, 65%) was the most commonly affected site followed in decreasing order by femoral (29/50, 58%), common iliac (9/18, 50%), popliteal (22/47, 47%), and calf veins (9/43, 21%). Trends were observed whereby luminal obliteration affected iliac veins and fibrotic bands affected femoropopliteal veins. CONCLUSIONS: Luminal obliteration, decreased caliber, fibrotic bands, ipsilateral muscle enlargement, and superficial collateral vein development are common CT findings in chronic DVT of the lower extremity.