bild

Coloured diffusion tensor imaging (DTI) magnetic resonance imaging (MRI) scan showing white matter fibres in the brain of a patient with Alzheimer's disease. Alzheimer's is a neurodegenerative disease where atrophy (shrinking) of the brain leads to memory loss, confusion, personality changes and ultimately death. Diffusion tensor imaging measures the direction of water diffusion, which in the brain reveals the orientation of nerve fibres. Red fibres have a left to right orientation, green a front to back orientation and blue an up and down orientation. (KEYSTONE/SCIENCE PHOTO LIBRARY/MARK AND MARY STEVENS NEUROIMAGING AND INFORMATICS INSTITUTE)