IMAGING OF TUBERCULOSIS .3. TUBERCULOSIS AS A MIMICKER OF BRAIN-TUMOR

Purpose: To show that intracranial tuberculosis (TB) often masquerades as brain tumour. Material and Methods: Forty-six patients with intrac ranial TB, who after CT at the local hospital were referred for surger y or radiotherapy of brain tumour, are presented. Sometimes the correc t diagnosis was first established during surgery for tumour. Results: The differentiation between TB and gliomas, meningiomas, metastases, o r lpmphomas may be impossible from the clinical history and CT finding s. Angiography, done in 25 of our cases, often helped by not showing t he expected tumour vasculature. MR, performed in 9 patients, helped by demonstrating a layered capsule on T2-weighted images in 4 of the les ions (hypointense rim outside hyperintense rim); the centres of the le sions were of decreased, usually very mixed T2 signal intensity. Concl usion: Even in patients with findings typical of brain tumour, TB rema ins an important differential diagnosis.