Lissencephaly. Coloured magnetic resonance imaging (MRI) scan of a brain (blue/yellow) with lissencephaly (smooth brain). The brain is seen in horizontal (axial) section, with the front of the brain at top. Normally the outer surface of the brain is heavily folded, but here it is smoother and the fluid-filled ventricles (brown, lower left & right) are greatly enlarged. People with lissencephaly are mentally handicapped and have uncoordinated movements. They also have a greatly reduced life expectancy. MRI uses radio waves and a powerful magnet to produce slice images of the body.