Venous thrombosis and segmental hypoperfusion in amebic liver abscess: MDCT demonstration and its implications.

ABSTRACT

PURPOSE: To report venous thrombosis and associated perfusion defect in amebic liver abscess (ALA) using MDCT. METHOD: MDCT images of 62 patients with ALA were reviewed for venous thrombosis and associated perfusion abnormalities. RESULT: The study found 43 (69%) patients with venous thrombosis portal vein thrombosis (PVT) occurred in 39, hepatic vein thrombosis (HVT) in 37 and inferior vena cava (IVC) thrombosis in 4. Combined PVT and HVT occurred in 33 (77%) patients. The portal vein thrombi remained localized in subsegmental branches in 25 patients and extended to segmental branches in 14. The hepatic vein thrombi were confined to peripheral branches in 18 patients; they progressed to the main trunk in 19 and to the IVC in 4. A wedge-shaped hypoattenuating zone suggesting ischemia was identified in 33 (77%) patients in portal phase 31 had combined PVT and HVT, 2 had HVT alone, but none had PVT alone. It occurred significantly more often with combined PVT and HVT than HVT alone (p = 0.05). Arterial phase enhancement occurred in 2 of 13 patients with multiphasic CT. All patients were symptomatic despite medical therapy and therefore required percutaneous drainage. About half of the patients were identified with ruptured abscesses. Segmental atrophy was observed in seven of nine patients who underwent follow-up CT. CONCLUSION: Combined PVT and HVT commonly occur with ALA and often manifests as segmental hypoperfusion in portal venous phase, indicating ischemia. The detection of such events by CT may be indicative of severe disease that requires aggressive management involving percutaneous drainage.