photo: brain
Image of the brain of a transgenic
mouse; © Brookhaven National Lab.

The technique has previously been used to look at tumors in breast tissue and cartilage in human knee and ankle joints, but this study tests its ability to visualize a class of miniscule plaques that are a hallmark feature of Alzheimer's disease.

Scientists have long known that Alzheimer's disease is associated with plaques, areas of dense built-up proteins, in the affected brain. Many also believe that these plaques, called amyloid beta (Aß) plaques after the protein they contain, actually cause the disease. A major goal is to develop a drug that removes the plaques from the brain. However, before drug therapies can be tested, researchers need a non-invasive, safe, and cost-effective way to track the plaques' number and size.

That is no easy task: Aß plaques are extremely small – on the micrometer scale, or one millionth of a metre. And conventional techniques such as computed tomography (CT) poorly distinguish between the plaques and other soft tissue such as cartilage or blood vessels.

A technique developed at Brookhaven, called diffraction-enhanced imaging (DEI), might provide the extra imaging power researchers crave. DEI, which makes use of extremely bright beams of x-rays available at synchrotron sources, is used to visualize not only bone, but also soft tissue in a way that is not possible using standard x-rays. In contrast to conventional sources, synchrotron x-ray beams are thousands of times more intense and extremely concentrated into a narrow beam. The result is typically a lower x-ray dose with a higher image quality.

In this study, researchers successfully used DEI in a high-resolution mode called micro-computed tomography to visualize individual plaques in a mouse-brain model of Alzheimer's disease.

COMPAMED.de; Source: Brookhaven National Laboratory