[Indications for magnetic resonance tomography in the diagnosis of cerebral diseases. Report of experiences with 1200 cases].

The current paper is a review of our experience of 1200 examinations of the brain, using magnetic resonance tomography (MRT), derived from a mixed neurological and neuro-surgical clinic. MRT has advantages in localisation and tissue characterisation. Localisation is improved by the ability to obtain coronal and sagittal images and by the absence of artifacts due to bone in lesions in the middle and posterior fossa. Some tissues and structures (blood, fat, vessels) produce relatively characteristic signals on MRT, which may be important in clinical diagnosis (eg. chronic subdural haematoma). A significant advantage of MRT is its excellent contrast resolution of soft tissues; this results in better demonstration of normal brain anatomy (eg. corticomedullary contrast), areas of demyelinisation (eg. multiple sclerosis) and certain cerebral tumours (eg. astrocytomas). On the basis of our experience, certain indications are defined, depending on the physical characteristics of the method; these are illustrated by clinical examples.