Echinococcosis of the liver and biliary tree: ultrasound, CT and post-operative evaluation

ABSTRACT

The sonographic and CT appearances of echinococcal lesions of the liver were studied in 100 patients. A classification of these lesions, that reflects the pathology and natural history of the disease [type I, simple fluid-filled cysts, type IR, lesions containing undulated membranes that represent detached endocysts secondary to rupture, type II lesions that contain daughter cysts and/or formed echogenic material called matrix, and type III, dead, densely calcified lesions], was proposed. The natural progression of hepatic echinococcal cysts is from type I to type III. Daughter cyst formation is part of the natural aging process. When hydatid cysts are infected, they lose their characteristic sonographic appearance and become hyperechoic on CT. These lesions were hypodense [30-40 HU] and did not show enhancement after intravenous contrast enhancement. Precise evaluation of the lesions arising from correlative use of ultrasound and CT permits proper staging and treatment