Diffusion tensor imaging (DTI):

Diffusion tensor image. Image courtesy of Thomas Schultz.

Diffusion tensor image. Image courtesy of Thomas Schultz.

uses magnetic resonance imaging (MRI) technology to measure the diffusion of water in brain tissue. This provides an image of the tracts and fibers of the brain, and thus allows for a greater understanding of the connections between different brain regions.

Further reading: The neuroimaging revolution