Alveolar echinococcosis of the liver. Findings of magnetic resonance imaging

The purpose of the present study was to evaluate the findings of MR imaging obtained in patients with Echinococcus multilocularis involving the liver. For 10 patients with alveolar echinococcosis of the liver, the MR findings were compared with the histopathologic findings after biopsy or surgery. Conventional T1-weighted spin echo, T2-weighted spin echo and T1-weighted spin echo after Gd-DTPA were employed. The signal from the lesions of alveolar liver echinococcosis on T1-weighted images was hypointense in 16 of 23 lesions (69.6%), hyperintense in 4 (17.4%), and isointense in 3 (13.0%). The signal from the lesions on T2-weighted images was hyperintense in 20 lesions (87.0%), hypointense in 2 (8.7%), and isointense in one (4.3%). On using Gd-DTPA, 7 of 21 lesions (33.3%) were observed with rim enhancement, and 14 lesions (66.7%) were non-enhanced. We describe our clinical experience together with the various findings of MR imaging as observed in the patients with alveolar echinococcosis of the liver. MR imaging excels in visualizing a low-intensity rim and small cystic foci, with liquefaction necrotic foci displaying a variety of signal intensities. After Gd-DTPA administration, the surrounding inflammatory granulomatous foci could be more clearly visualized. (author)