DTI stands for Diffusion Tensor Imaging and is a variant of MRI. This method looks at how water molecules can move freely within tissue. Just as water in a garden hose cannot move freely in all directions, but only in the direction of the hose, the same is true of connections between brain regions. The water contained in the white matter can only move freely along the direction of the connection. DTI measures in which direction the water molecules can move best across the brain, and maps this out. These results can be processed with a computer into a three-dimensional representation of the structural connections in the brain, and in which direction they run.

This figure shows a reconstruction of the connections in and around the corpus callosum, measured with DTI. At the bottom of the picture, you can see the connections from the spinal cord.

Author: Job van den Hurk (translated by Melanie Smekal)

Image: Marcel Loeffen