Computed tomography, like conventional X-ray imaging, works on the principle of X-rays...

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Computed tomography is based on the principle of an X-ray tube rotating around the patient while the examination table moves slowly. The X-rays, which are more or less attenuated by the patient's tissue, are captured by detectors on the opposite side as a volume data set and forwarded to a computer for further processing. Modern devices with several rows of detectors can capture several layers of the body simultaneously, which speeds up the examination process considerably. You benefit from shorter examination times, but also from the possibility of a more precise diagnosis of moving body parts (e.g. the beating heart).

The volume data set obtained can be visualised using conventional axial sectional images or reconstructed in any plane or as a 3D image.

Some examinations require the administration of contrast medium. This is usually administered via a vein in the crook of the elbow during the examination and is used to visualise blood vessels and soft tissue structures.

The range of applications for computer tomography is very extensive today. Every region of the body can be examined depending on the relevant question.

Common indications for computerised tomography are

Head

  • Diagnosis of cerebral haemorrhages and strokes
  • Craniocerebral trauma (e.g. skull fractures)
  • Brain tumours
  • Degenerative changes in the brain substance
  • Visualisation of vessels, CT perfusion, Further information

Neck

  • Localisation and extension of tumours
  • Detection of enlarged lymph nodes (lymphomas)
  • Trauma or degenerative changes to the cervical spine
  • Visualisation of vessels (e.g. carotid artery), Further information

Chest

  • Localisation and extent of lung tumours
  • Acute and chronic inflammation and changes in the lungs
  • Visualisation of the main artery (aorta)
  • Trauma to the chest
  • Trauma or degenerative changes to the thoracic spine
  • Examinations of the heart (cardio-CT), Further information

Abdomen

  • Diseases of the upper abdominal organs, in particular the liver, pancreas and bile ducts (e.g. inflammation, tumours)
  • Traumas of the abdominal organs
  • Diagnostics of the gastrointestinal tract (e.g. tumours, inflammations, CT colonography), Further information
  • Visualisation of the large abdominal vessels
  • Injuries or degenerative changes to the lumbar spine and pelvis
  • Osteo-CT (bone density measurement)

Extremities

  • Injuries and degenerative changes to the skeleton

Interventions

  • CT-guided punctures to obtain tissue samples (biopsies)
  • CT-guided insertion of drains
  • Specialised pain therapy

Many CT scans use a contrast agent containing iodine, which is injected via a peripheral vein. The following questions should be clarified in advance of such examinations:

  • Is kidney function normal?

As most of the contrast medium is excreted via the kidneys, a current blood value (creatinine, GFR) should be available. If necessary, kidney function must be supported by means of a fluid infusion before the examination.

  • Is there hyperthyroidism?

As the contrast medium contains iodine, hyperthyroidism could be exacerbated, so current thyroid parameters should be determined in advance (TSH, fT3, fT4). It may be necessary to block thyroid function with medication.

  • Is there a known allergy to iodine-containing contrast media?

If allergic reactions are known, anti-allergic medication must be administered in advance.

 

You should therefore inform us of any known pre-existing conditions before the examination so that we can make appropriate preparations if necessary.

Fasting is only necessary if you are known to be allergic to contrast media, or if you are expressly advised to do so.

For many examinations of the gastrointestinal tract, it is necessary to drink fluids (water) before the examination in order to visualise the normally collapsed structures of the gastrointestinal tract. We will inform you of this before the examination.

The examination is carried out lying down, usually on the back, on an examination table. This moves the body region to be examined through the opening of the computer tomograph during the scan. During the examination, the patient should lie as still as possible to avoid movement artefacts. Swallowing should be avoided during the scan, especially for examinations of the neck. Breathing commands are often given during examinations of the chest and abdomen.

During the injection of contrast medium, many patients experience an internal feeling of warmth and a strange metallic taste may occur in the mouth, both of which are completely harmless and subside after a short time.

When examining the lower abdomen, especially the rectum and colon, it is often necessary to inject water into the rectum via a small intestinal tube before the examination in order to better delimit the intestinal structures from the surrounding tissue and to be able to assess the intestinal lumen.

 

We offer optimised paediatric examination protocols for children.