In 1895 a German physicist called Wilhelm Rontgen made a discovery which would later revolutionise the field of medical diagnosis. Whilst not fully understanding his discovery, he established that invisible rays could penetrate through a black card covering a cathode ray tube, causing the tube to fluoresce. He later realised that they would penetrate opaque materials, to an extent depending on the density of the material. These rays, he called X-Rays. Seventeen years later it was established that an X-Ray is a form of electromagnetic radiation, with a wavelength much shorter than that of visible light.
The implications for medical science were immediate, and by 1901, when he received the Nobel Prize for physics, X-Ray tubes were commercially available for medical use. An image of a part of the anatomy is taken by bombarding the appropriate part of the body with X-rays. These are absorbed at a rate depending upon the density of the material, muscle and flesh absorbing less than bone. After passing through the body, the rays are projected onto a phosphor coated plate, forming an image of the inside of the body. It was thus possible to establish immediately whether bones were broken and to locate metal objects which may have become lodged inside the body.
Modern versions are of course far more sophisticated, a popular technique called computerised axial tomography (CAT) being one example. This process involves scanning the body with X-Rays, the data concerning the amount of radiation absorbed being converted by computer into a picture. This process is so accurate that it can distinguish between fat, muscle, bone and water. Tissue can be examined for tumours which would not be visible with standard X-Ray machines. As well as being used for diagnosis of illnesses, they are now also used for treatment. Cancerous tissue is bombarded with X-Rays to destroy it. The surrounding healthy tissue is also destroyed but this will normally repair itself.
