Presentation
Right upper quadrant pain
Patient Data
A heterogenous fluid filled cystic structure is seen in segment IV of the liver. There is peripheral calcification within the wall of the cyst. No septa or daughter cysts are seen within. There are no other liver lesions.
Incidental small areas of atelectasis bibasally.
Note the high signal intensity on T2 weighted imaging and low signal intensity on T1FS imaging, consistent with fluid density.
Case Discussion
Hydatid cysts occur secondary to infection with a parasitic worm of the genus Echinococcus. These cysts are most commonly found intrahepatically but may also be seen in the lungs and other solid viscera such as the spleen.
They characteristically are quite large, with mixed attenuation within (depending on the composition of the cyst fluid) and will often demonstrate peripheral calcification of the wall, with or without septations, daughter cysts within the parent cyst and/or satellite cysts. Their walls demonstrate contrast enhancement on both CT and MRI.