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Computed tomography (CT)

Computed tomography is a modern imaging method that enables a detailed insight into the human body.

An X-ray tube rotates around the patient, emitting at the same time a fine bunch of X-rays. Opposite to the tube, a system of detectors rotates around the patient. This helps to take pictures of the slices of the body organs from nearly a thousand of directions.

This sums up to hundred thousands of measured values that will be further processed by a computer. The result will be non-overlapping cross-sectional images of the examined region of the body. The measurement period for each body region is just a few seconds.

The examination is painless and uncomplicated for the patient.

The special advantage of CT over the conventional X-ray is a better depiction of the soft tissues, i.e. internal organs.


It is possible to examine large parts of the body in a very short time. The special recording technique helps to avoid the overlapping of the organs that appear in an X-ray image (summation image) and to make a more accurate diagnosis. Through post-processing of the measured data it is possible to produce three-dimensional images of the examined area. Furthermore, by means of density measurements one can determine whether e.g. what is seen is an adipose tissue, a fluid or a firm tissue structure.

Nowadays, computed tomography has a very wide range of application. With examinations of the lungs, many conditions of the abdominal cavity and the quick examination of the head (e.g.), there is no other method that can provide decisive information so quickly and precisely. Especially in case of accidents and strokes, computed tomography is indispensable.


Computed tomography (CT)



CT Information Sheet
Contrast Media Information Sheet (German) 

Further information 

How is the examination performed?

During the examination, the patient lies in a supine position on a narrow table that is slowly moving forward into the ring-shaped opening of the device. With 70 cm in diameter, it is relatively wide, and the scanner itself looks more like a ring than a tube, which is why you do not feel trapped and do not suffer from claustrophobia.

In case of claustrophobia, CT will often be the only examination of choice, due to the fact that the scanner does not make the patients feel trapped. During the examination, you can talk to the doctor or X-ray assistant over the intercom at all times.

The examination itself is absolutely painless and takes 2 to 10 minutes, depending on its complexity. During the examination you should be lying as relaxed and still as possible. An automatic voice will be possibly giving you exact breathing instructions. Please stick to them, because internal organs can take different positions with every breath.

Preparation for the examination

The examination of the head (skull and brain) and also intervertebral discs and skeleton contents do not require any special preparation. About 2 hours before the examination of the abdomen and pelvis, you should mostly drink 1-2 litres of contrast material, in order to mark the gastro-intestinal tract. If you are allergic to iodine or have problems with your thyroid gland, you should tell about it beforehand, so that you get a barium-containing contrast medium to drink. As a rule, you should not fast before the examination, it is even recommended to have a light meal.

Contrast media in CT

During the majority of CT examinations, it is necessary to administer a contrast agent into a vein. Contrast agents serve the purpose of better depicting well-perfused tumours or inflammations. They can be injected into an arm vein, producing images that can be better evaluated. With examinations of the abdominal cavity, you can be asked to take the contrast agent. As a rule, all contrast agents are well-tolerable and will be excreted through the kidneys after a short time. Some (few) people are allergic to iodine-containing contrast media. Therefore, before the examinations requiring the administration of a contrast agent, you should fill in the questionnaire, in order to determine possible problems even before the examination.

If you are allergic to any contrast agents or other substances, you should inform us about it while arranging your examination appointment, so that we can eventually choose another examination method. In patients over 50 or those with a suspected kidney disease, we would ask for the current creatinine level.

Last update: June 2015
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