[Visualization of brain function using MRI-MR functional brain imaging].

The effects of photic stimulation on the visual cortex of human brain were studied by means of gradient-echo magnetic resonance imaging (MRI). Fast low-angle shot (FLASH) MRI was used to monitor changes in brain oxygenation in the human visual cortex during photic stimulation (PS). Whole-body 1.5 T clinical MR system was used. Elevation of image intensity up to 2% was observed in primary and associative visual cortex, corresponding to an increase of blood oxygenation in regions of increased neural activity. After the PS was switched off, the MR signal fell below the pre-PS baseline level, which may be understood as an displacement of the oxygen-hemoglobin dissociation curve (the Bohre effect).