[Imaging diagnosis of hepatic alveolar echinococcosis]

To study the characteristics of hepatic alveolar echinococcosis in B mode ultrasonography (BU), computerized tomography (CT), and magnetic resonance imaging (MRI) so as to increase the pre-operative diagnostic rate.

The data of forty-six cases with hepatic alveolar echinococcosis who underwent operation during the period January 1984 to December 2000 were analyzed and compared with the pathological findings of the resected specimens. All of the cases were examined by BU and CT, and 12 of them were examined by MIR.

The imaging characteristics of the 46 cases were divided into three types: infiltration (41 cases, 89.1%), calcification (39 cases, 84.8%), and cavity with liqueficaction (37 cases, 80.4%). Nine imaging signs were found to be specific to hepatic alveolar echinococcosis and of diagnostic significance: halo belt sign, calcification sign, annual ring sign, invacuation sign, cavity with liqueficaction sign, grotto sign, peninsula sign, alveolar sign. With these signs, the diagnostic accuracy rate reached 97.7% in this series.

There are nine imaging diagnostic signs specific to hepatic alveolar echinococcosis. They help detect the location, pathology of this disease and determine operation program. Identification of only one of them is adequate for diagnosis of hepatic alveolar echinococcosis.