[Functional cerebral neuro-imaging at 1.5 Tesla. The results of visual, sensorimotor and auditory stimulations]

Functional activation of the cerebral cortex can be observed with a standard 1.5 Tesla MRI magnet. We used a repeated FLASH 2D one-section sequence with a long echo (TE = 60 ms) and a small passing band. Modification of regional cerebral oxygenation due to neurone activation seems to be the main source of contrast. Sensorimotor stimulation was effected by an unusual mobilization of the fingers. Visual stimulation was performed by intermittent lightings at a frequency of 8 Hz. Auditory stimulation relied on listening to speech sounds. Signal increases were localized on the cerebral cortex with precise anatomico-functional correlation. Using a clinical 1.5 Tesla magnet requires an adequate treatment of data. Thus, stimulated cerebral activity can be portrayed by MRI therapy opening a new way for anatomico-functional cerebral studies.