Hydatid disease: MR imaging study.

Fifteen patients with hydatidosis, 13 with hepatic echinococcosis and two with isolated lesions of the spleen and the shoulder, were examined with magnetic resonance (MR) imaging. Of the 13 patients with hepatic hydatidosis, four had secondary peritoneal lesions, and one also had involvement of the dorsal spine. The presence of a hypointense rim and a multiloculated or multicystic appearance are distinctive features. When evaluating the viability of hydatid cysts the authors found that MR imaging findings were not particularly valuable, as the MR imaging signs (daughter cysts and detachment of the membranes) are rare and are also evident at computed tomography and ultrasound examinations. T2 measurements were not useful due to the wide range of values obtained. Despite these limitations, MR imaging is still an important technique in the study of echinococcosis to depict the presence of a rim as a characteristic sign and to obtain a complete anatomic evaluation.