[Diagnosis by imaging of the brain affected by AIDS].

Neurological complications are frequent in patients with the acquired immunodeficiency syndrome (AIDS). They are caused by neural structures being affected by the virus itself, and/or the development of opportunist infections and neoplasias secondary to the immunodepression. Cerebral toxoplasmosis and human immunodeficiency virus (HIV) encephalopathy are the commonest encephalopathic disorders seen in these patients. Primary cerebral lymphoma, progressive multifocal leukoencephalopathy (PML), tuberculosis, etc. are less common. Computerized tomography (CT) and magnetic resonance (MR) are the most suitable techniques for diagnosis and follow-up of cerebral involvement in patients with AIDS. Although MR is more sensitive for the detection of lesions, particularly those in the white matter, CT is still the most widely used technique since its more readily available. Also it needs less cooperation from the patient. Although on some occasions combination of both techniques may suggest the aetiology of the lesion, these techniques are non-specific.