Objective.

The characteristics of intracranial tuberculoma on computed tomography (CT) and magnetic resonance imaging (MRI) are not well known. The authors reviewed the features of tuberculoma on CT scans and MRI. The authors also correlated the MRI characteristics on various pulse sequences with neuropathological findings.

Methods.

The charts of patients with intracranial tuberculoma were consecutively reviewed during the period from 1988 to 1999. The diagnosis of tuberculoma was based on pathology (n = 19), clinical or neuroimaging response to tuberculous chemotherapy (n = 57), or evidence of systemic tuberculosis (n=24). Neuropathological specimens of tuberculoma were graded for the amount of fibrosis, gliosis, necrosis, and cell types (lymphocytes, macrophages, plasma cells).

Results.

One hundred patients (43 men) were identified. The age range was 1 to 75 years (mean = 30 y). The number of lesions ranged from 1 to > 100 (mean = 4.5 lesions/patient). Thirty-one patients had solitary lesions, whereas 69 had multiple lesions. Thirty-seven patients had hydrocephalus. After contrast administration, >450 lesions were seen on CT and MRI images in all 100 scans. The diameter of these enhancing lesions ranged from 1 mm to 5 cm. Lesions > 1 cm showed varied enhancement, including irregular shapes, ringlike shapes, open rings, and lobular patterns. Targetlike lesions were seen in only 2 patients. Other features included cortical and subcortical infarcts (12 patients), calcification (10% of lesions), edema (33 patients), meningeal enhancement (12 patients), mass effect, and/or midline shift (18 patients). A hypointense core with a hyperintense rim was the most common signal characteristic on T2-weighted MRI. The central hypointensity on T2-weighted and fluid-attenuated inversion recovery (FLAIR) images reflected extensive necrosis and hypercellularity.

Conclusion.

Multiple tuberculomas and infratentorial locations were more common in the authors'patient population than in previous reports. The MRI signal characteristics of intracranial tuberculoma are extremely diverse. An isointense or hypointense core with a hyperintense rim on T2-weighted and FLAIR images is the most common presentation. Core hypointensity of lesions on these images is related to necrosis and the large number of cells.