WHAT IS A CT SCAN?
Computed tomography is used since 1974 in order to obtain images from inside the body.
The decisive advantage over traditional X-ray examination is that the CT can be analyze a region of the body layer by layer and thereby provides overlay photos. Since the thickness of the recorded body layers is in modern appliances just 0.5 mm, very small lesions can be detected in a CT scan.
The digital information of a CT scan can then exposed on a film or for example are shown as three-dimensional display on the monitor.
THE ROAD TO THE SECTIONAL IMAGE
Inside the CT scanner is an X-ray machine moves in a circle around the patient. Here shots from many angles are created.
Unlike the normal X-ray, where for example the whole thorax is imaged at once, here’s a fan-shaped X-ray detects only a very small area of the body. The radiation usually permeates several different tissues and organs successively. A detector on the opposite measures weakening of X-rays from the superposition of organs. From the individual values of different shooting angles, a computer can then calculate an overlay free-sectional image. If the patient is slowly moved through the device, the physician gets a set of sectional images of the desired region of the body layer by layer. Through more complex calculations, it is then possible to reconstruct detailed 3D views of individual organs and display them on the screen.