MRI of intraventricular cysticercosis : surgical implications

Our goal was to evaluate the role of Gd-enhanced MR in the diagnosis and surgical planning of intraventricular cysticercosis cysts. Thirty-three patients with intraventricular cysticercosis were evaluated with Gd-enhanced MRI including follow-up studies ranging over time periods from 6 months to 8 years. The patient age ranged from 17 to 65 years. All had lived in Mexico or Central America. Twenty patients had surgical removal of the cysts. The majority of patients (18 of 20) who had surgical removal of the cyst showed improvement with resolution of hydrocephalus. Two of 20 patients required additional shunting to alleviate hydrocephalus. In these two patients, Gd-enhanced MR showed cyst wall enhancement. Ependymitis with adhesion was found at surgery in these two patients. Nine patients had shunt placement; one of nine patients showed cyst enlargement 2.5 years later that required surgical removal. Of the remaining eight patients, four showed irregular, thick, ring-like enhancement mimicking a neoplasm on follow-up imaging studies. Four patients with cysts in the lateral ventricle did not require treatment. Two of the four patients showed irregular, thick, ring-like enhancement on follow-up imaging studies. Gadolinium-enhanced MR is more sensitive than contrast-enhanced CT for detecting ependymitis, which is essential in deciding whether surgical removal of the cyst or shunt placement is indicated. A degenerating intraventricular cysticercosis cyst may present as an irregular, thick, ring-like enhancing lesion or a nodular enhancing lesion with varying degrees of surrounding edema, mimicking a neoplasm.