Specific Imaging Findings

Brain parenchymal cysticercosis (CC) usually manifests with multiple lesions. The lesions are commonly located at the junction of gray and white matter, reflecting hematogenous disease spread. The early (vesicular) infection stage is seen as CSF density/intensity cysts with a tiny eccentric calcification representing the scolex, usually without surrounding edema and with possible minimal peripheral enhancement. The scolex is best seen as a bright dot on FLAIR images. The colloidal stage is usually a cyst with ring contrast enhancement and surrounding edema. The cyst density/intensity may be slightly different from CSF. The granular stage shows a contracted nodular or ring enhancement without a cystic component. There may be a thin rim of surrounding edema. The final nodular stage is seen as a calcified lesion which may show a rim of high T1 signal, contrast enhancement, and surrounding edema. Most patients harbor parasites in all phases of their evolution, leading to frequent heterogenous imaging appearance. Delayed post-contrast T1WI identifies the highest number of CC lesions.

Pertinent Clinical Information

Neurocysticercosis is a major cause of acquired epilepsy in most low-income countries and it is becoming more common in high-income countries because of increased migration and travel. The most common clinical presentation is seizures (over 70%) and headache. Calcified CC lesions may be incidentally seen in patients investigated for other disease processes.