FUNCTIONAL MAGNETIC-RESONANCE-IMAGING AT 1.5T DURING SENSORIMOTOR ANDCOGNITIVE TASK

Functional activations of the human brain cortex were observed with a standard 1.5-tesla MR imaging system using a long time echo fast low-a ngle shot sequence. Neural activation increases regional cerebral bloo d flow resulting in increased capillaries and venous blood oxygenation . Processing requires adapted algorithms because the time course of in tensity signal showed fluctuations of the baseline. The use of a 'foll ow-up' method to generate activation maps is proposed. Brain activatio n was detected in striate cortex during photic stimulation and in sens orimotor areas while subjects were moving their hands. In mental image ry tasks, we observed a primary and secondary visual cortex activation during memory recall of the flashing light. Motor ideation showed an activation of the rolandic areas.