X-ray vision reveals brain details

Special imaging method provides more accurate views

Deep view of the cerebellum: White cerebral substance (orange) differs from two types of gray matter (blue: stratum granulosum, yellow: stratum moleculare). Also blood vessels (red) and individual cells (lower image) are clearly visible. © Martin E. Schwab / SNSF
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Basel researchers have looked with a special X-ray as accurate into the human brain as never before. With the new method, they have succeeded in making even individual cells visible without contrast medium. The technology could help in the fight against diseases such as cancer in future, the scientists write in the journal "Journal of The Royal Society Interface".

Imaging procedures have long since become indispensable in modern medicine. However, the methods used today have drawbacks: Although X-ray machines deliver sharp images of bones and teeth, soft tissue in the body - from which, for example, the brain is built up - can hardly be distinguished from one another. Magnetic resonance imaging solves these problems well, but their spatial resolution is too low to image individual cells.

Deflected X-rays

However, researchers led by Bert Müller from the Biomaterials Science Center at the University of Basel have now taken pictures in which not only the soft tissues of the brain can be distinguished, but even individual cells can be seen. They used a completely new measurement technique - a complex type of X-ray called phase-contrast imaging.

In doing so, Müller and his team measured how much a certain tissue deflects the rays and not - as with conventional X-rays - how much radiation the tissue absorbs.

Mapping human cerebellum

In the Journal of the Royal Society Interface, the researchers report how they use the method to map a human cerebellum. The pictures show blood vessels. The white matter and various types of gray matter are clearly different. According to the scientists, individual so-called Purkinje cells are also clearly visible - a relatively large type of cell typical of the cerebellum. display

"It's like having such sharp eyes that you could see a small truck on the moon, " says Müller, describing the merits of the new method. It is the first time that individual brain cells are visualized within a centimeter-sized tissue block without staining them with a contrast agent.

Interesting for the medicine

For living people, however, such detailed investigations will probably not be possible according to Müller. The required X-ray dose is so high that it is dangerous for the patient. Nevertheless, the technique is highly interesting for medicine.

In a project by the Swiss National Science Foundation SNSF, for example, M ller, in collaboration with researchers from ETH Zurich, is attempting to detect the tiniest blood vessels in adult cancers taken from mice. This is to show how tumors grow and how to prevent them.

(idw - Swiss National Science Foundation SNSF, 10.08.2010 - DLO)