CT and MRI findings in cerebral hydatid disease

Abstract

Cerebral hydatid cysts account for 2% of all intracranial masses. Preoperative diagnosis is important since cyst rupture and spillage may cause an anaphylactic reaction. CT is the primary modality for the diagnosis. Two forms of cerebral hydatid cysts have been reported on the basis of CT appearances: unilocular and multilocular. Demonstration of the cyst wall is important for the diagnosis. MRI is superior to CT for demonstrating the cyst capsule and perifocal oedema. We retrospectively reviewed the CT and MRI findings of 6 surgically proven cases of cerebral hydatid cyst and compared the two modalities on the basis of their demonstration of findings helpful in the diagnosis, such as the capsule and perifocal oedema. In 1 case CT showed the capsule. In 2 cases MRI showed a hypointense capsule around the cyst on T2-weighted images. While CT is the modality of choice, in clinical practice MRI is superior for demonstrating the cyst capsule, which is a helpful finding in the diagnosis and can be used in inconclusive cases.