MRI OF ABDOMINAL HYDATID-DISEASE

Seventy hydatid cysts in 30 patients were studied with magnetic resona nce imaging (MRI) and computed tomography (CT); all cases were confirm ed surgically. MRI detected all cysts when confined to solid organs, w hereas small-sized cysts (less than or equal to 2 cm) may be missed wh en located in the peritoneal cavity. Hydatid cysts of less than 3 cm ( noncomplicated) present no specific findings of hydatid disease. MRI f indings suggesting hydatid disease demonstrate a relatively thick hyda tid cyst wall, daughter cysts, and germinal membrane detachment. T2-we ighted images proved to be superior to T1- or PD-weighted images in de monstrating hydatid cyst wall thickness, germinal membrane detachment, and daughter cysts. In all spin-echo sequences, the maternal cystic c ontent presented much higher signal intensities than that of daughter cysts. This difference in signal intensity is more obvious in T2-weigh ted images, except in complicated, infected cases. CT proved to be sup erior to MRT in demonstrating wall calcifications.