Diffusion Imaging (Introduction)

Functional MRI opened a hugely important window onto the brain by revealing the specific areas of the brain involved in any number of activities or responses to outside stimuli. Seeing, learning, feeling pain. The list goes on. But another piece of the puzzle remained: namely, how did these areas of the brain communicate with one another?

Since the 1990s, Center researchers had been developing a technique called diffusion tensor imaging, an MRI-based method that allowed imaging of the long nerve fibers that facilitate communication between different areas of the brain by tracking water molecules as they travel along them. By the mid-2000s, both scanner technology and reconstruction algorithms had advanced to the point where the researchers could discern tightly packed fibers running in different directions and often crossing over one another—thus launching a new era of what we know now as diffusion imaging.