In the article we present pathological intracranial substances and lesions, which produce high signal intensity on T1-weighted MR images. Six groups of substances are discussed: 1. Gadolinium - based contrast agents, 2.hemoglobin degradation products (intra- and extra-cellular methemoglobin), 3. lipid-containing lesions (lipoma, dermoid cyst, implanted fatty materials, laminar cortical necrosis...

The present essay is illustrated with magnetic resonance images obtained at the authors' institution over the past 15 years and discusses the main imaging findings of intraventricular tumor-like lesions (colloid cyst, oligodendroglioma, astroblastoma, lipoma, cavernoma) and of inflammatory/infectious lesions (neurocysticercosis and an atypical presentation of neurohistoplasmosis). Such lesions ...

A 38-year-old woman presented to the emergency room with a 7day history of severe headache, nausea, and vomiting . The neurologic examination was normal. Both CT and MR showed a mass at the foramen of Monro (Fig . 1). The CT appearance was atypical for colloid cyst; therefore, the diagnosis of xanthogranuloma was suggested. The mass was surgically removed , and the final pathologic diagnosis wa...