[Imaging diagnosis and classification of hepatic cystic echinococcosis].

OBJECTIVE: To investigate the imaging characteristics of hepatic cystic echinococcosis in different imaging examinations and to formulate an imaging classification. METHODS: The data of pre-operative imaging examination of 2 039 cases with hepatic cystic echinococcosis, who underwent operation during the period January 1984 to December 2000, by B mode ultrasonograohy (all cases), X-ray computed tomography (909 cases), and magnetic resonance imaging (24 cases) were analyzed, being compared with the pathological findings of the resected specimens. RESULTS: Imaging examinations succeeded to identify not only the location, size, and form of hydatid cyst in liver, but also the typical pathomorphology of complications. The hepatic echinococcosis can be divided into seven imaging-diagnostic patterns: solitary cyst (1 625 cases, 79.70%), multiple cysts (414 cases, 20.30%), primary hydatid cyst with daughter cysts (1 114 cases, 54.63%), calcified cyst (186 cases, 9.12%), consolidated cyst (28 cases, 1.37%), cyst with infection (391 cases, 19.18%), and ruptured cyst (298 cases, 14.62%). CONCLUSION: A new diagnostic system of hepatic echinococcosis has been formulated based on imaging examination and by reference to clinical manifestation. It helps select appropriate operation program.