Healthy adult human brain viewed from the side, tractography

Side view of connections in the brain of a healthy 29 year old female human. These nerve fibres are depicted here inside the outline of a brain which sits within a silhouette cutout of a head. The brain is viewed as if looking through the head from a person's right ear. Brain cells communicate with each other through these nerve fibres, which have been visualised using diffusion imaging tractography. Diffusion weighted imaging is a specialised type of magnetic resonance imaging (MRI) scan which measures water diffusion in many directions in order to reconstruct the orientation of bundles of axons. Tractography is used to indirectly model these bundles of axons (nerve fibres), which transmit information between cortical regions at the brain's surface. The brain measures approximately 18 cm from front to back.