The value of computed tomography in osseous hydatid disease (echinococcosis).

The authors report three cases of osseous hydatid disease (echinococcosis) in which examination by computed tomography (CT) was found to be helpful in establishing the diagnosis. Recognition of this rare bone infection in orthodox radiographs is notoriously difficult, but is aided by knowledge of the patient having lived in an area in which the disease is endemic. In two instances, one involving the shoulder and the other the thoracic spine, radiological abnormalities had been attributed at first to tuberculosis. In the third case, in which a destructive lesion in the sacrum had been interpreted correctly, CT studies provided confirmation of a recurrence. CT has proved to be an effective and sensitive method of demonstrating these destructive lesions in bone, of determining their spread, and of establishing the presence of other hydatid cysts in adjacent soft tissues. This technique has been found to be of value in preoperative planning of the surgical approach to hydatid lesions of the skeleton.