A heterogenous signal is seen involving the choriod plexus in the right lateral ventricle. On post contrast study, enhancement of the choroid, ependymal enhancement with minimal parenchymal enhancement is seen.

Choroid plexus tuberculoma

Tuberculosis is the most common non-purulent infection of the central nervous sytem. Tuberculomas or tuberculous abscesses are characterized by a 0.5 to 4 cm caseous nodule, with a peripheral granulomatous capsule.

The lesions are usually of reduced density or isodense with brain before contrast medium. Peripheral enhancement is seen after intra venous contrast medium. In some cases, there is a dense ring shadow which can simulate gliomas or pyogenic abscesses. Enhancement could also be nodular or a fine irregular ring. Mass effect is not usually striking.

Central zone of liquefying necrosis is usually of lower signal than the surrounding brain edema on T1WI; the capsule is commonly isointense with brain and may be visible on both T1WI and T2WI. Strong enhancement of the capsule is seen on intravenous administration of Gado-DTPA.

Dr. Deepak Patkar, MRI Nanavati, Mumbai