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New Tools for Understanding White Matter Disease using Diffusion MRIMagnetic resonance imaging (MRI) is a rapidly-developing technologyfor imaging humans that normally does not need any invasive procedures such as injections or exposure to radiation. MRI is able togive us highly-detailed images of the inside of the body, and cantherefore tell us a lot about the presence or development of disease.One recent advance in MRI is known as diffusion MRI , which looks atthe random motion of water particles in the body. This is particularlyinteresting when taking images of the brain, because water tends tomove more along the directions of the connections inside thebrain. These connections in the brain, known as white matter , arecrucial to keeping the brain working correctly. They are the pathwaysthat carry information from one part of the brain to another, and ifthey are damaged, the brain cannot perform even simple tasks.Diffusion MRI is unique in its ability to study these pathways, basedon how water flows along them.There are many diseases that affect the white matter in the brain, andit can be very hard to understand exactly how the disease attacks thewhite matter, to predict how the disease will develop in a particularperson, and to decide what the right treatment is for thatperson. Fortunately, because diffusion MRI is sensitive to changes inwhite matter, it is an excellent way of finding out about thesediseases. For example, if the disease is breaking down the pathways,water stops moving along them, or leaks out of them, and diffusion MRIcan see this.One of the big outstanding problems is that everyone's brain isunique: every brain is a slightly different shape, and their internalwiring is also different, so a picture of one person's brain doesn'texactly line up with another person's brain. This makes it difficultto make simple comparisons of one set of people (say, patients with adisease) with another (healthy people). In this project we hope todevelop new mathematical techniques for deforming diffusion images sothat one person's brain matches another's. This is very difficult toget exactly right, particularly for some parts of the brain that varyenormously from person to person. However, if we can succeed in ourmathematical research, and manage to match the brain images fromdifferent people together, we can then compare the informationpathways in the brain for different groups of people.If we can achieve this, then we can start to learn about how aparticular disease causes the brain to degenerate over time. Fordiseases like multiple sclerosis, we can use this to evaluatedifferent drug treatments, to help speed up the developments of newand better drugs. In people who have suffered a stroke, we can look atthe pattern of white matter damage, and possibly work out exactly whatkind of physiotherapy treatment will help them recover mosteffectively. In babies who have been born much too early, we can usethe diffusion imaging to find out which protective treatments workbest at helping the babies develop normally.
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