Sparing X-Ray
A method for obtaining high-resolution X-ray images
Russian physicists have found a way to reduce the radiation dose while visiting X-ray study. To do this, construct a device not much different from the usual set in each hospital. New method of X-rays is based on a fundamentally different property of X-rays passing through the object.
As a result, the pictures are much more contrast and radiation dose can be reduced to a few dozen times.
It has been exactly one hundred years since Roentgen won the Nobel Prize for the discovery of a new type of radiation. People have learned to use the property of X-rays penetrate through objects and show their internal structure. Although X-rays harmful to living organisms, however, this is the only way to diagnose many human diseases. In one picture we recruit fluoroscopy dose of 60 mR, and the X-ray yields 500 mR, which is comparable with the annual rate derived from natural background. Is it possible to reduce the radiation dose while visiting X-ray room?
It appears possible, dozens of times.
In the 90-ies of XX century physics Victor Inga and Elena Belyaevskaya organized in St. Petersburg, x-ray laboratory. They are examined by X-ray crystal defects.
In one experiment, scientists have noticed the pictures pattern nylon cloth, which was wrapped around the crystal. So they accidentally discovered a very simple way to get the contrast x-rays. The first experiments, of course, carried out on non-living objects.
Before put radiation source, for example, a plastic capillary, followed plate set of the silicon single crystal under strictly defined angle. X-rays passing through the plastic, slightly refracted, and the ones that did not touch the subject, remain straight. Crystal behind the object under study, reflects from its surface both types of rays refracted and undiffracted on the photographic plate.
The denser any part of the object, the stronger they are refracted rays, and the picture will be a bright spot. Accordingly rays on the path which costs nothing, reserve the dark background.
Thus, scientists from St. Petersburg have discovered a new way to get x-rays. This method utilizes the effect of refraction, whereas the conventional X-ray absorption v rays.
X-rays passing through our body is absorbed by different parts of it in different ways. Bone, consisting of calcium, and therefore more dense, delay radiation is stronger in the photo they will match the bright place. Soft tissue contrast, the rays pass well and leave dark spots in the picture.
But then the picture would be difficult to distinguish between areas characterized by low density, such as soft tissue, blood vessels and lymph nodes. A new method gives a very contrasting pictures, he distinguishes between objects similar in density, because the silicon chip detects the slightest deviation rays, even from objects the size of 10 microns.
Scientists soon realized that the new method may be useful in medicine. X-ray machine, built on this principle will differ little from the usual. All its parts v standard, commercially available on the stream.
However, to introduce innovation in the Russian inventors failed, X-ray lab burnt, her owners had left to try his luck in America. Fortunately, there are still too new to have been slow to use. So Russia is still possible to get a unique method.
Our phase contrast method is effective in the diagnosis of early forms of cancer. We took pictures of a thin slice of the female breast and got a picture metastases, - says Vladimir BUSHUEV, Professor of Solid State Physics, Moscow State University, one of the authors of the patent. It was he who developed the theory of the method and solved the problem of three-dimensional reconstruction of the internal structure of the object.
In his view, the invention can be used in other devices, such as customs introscopes.
Author news: Tatiana Pichugin
Source: Agency InformNauka,
Contact information: tel.: (095) 267-54-18, pitchugin@mtu-net.ru
