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Ionising radiation

Environmental Radioactivity - Medicine - Occupational Radiation Protection - Nuclear Hazards Defence

Ionisierende Strahlung


Different procedures are used to detect a disease. The patient’s medical history, also referred to as anamnesis, is compiled first to establish the diagnosis. Anamnesis is the basis of all further diagnostic procedures. These include not only physical examinations (for example palpation) or laboratory tests (for example blood) but also imaging procedures such as diagnostic X-ray and ultrasound examinations. In the following, imaging procedures will be described in more detail.

X-ray photograph

X-ray diagnostics – the procedure

In X-ray diagnostics, a difference distinction is made between three techniques: radiography, fluoroscopy and computerized tomography (CT).

Medical use of radiation during pregnancy

If a pregnant woman is exposed to ionizing radiation, there is a risk of radiation-induced malformations and developmental disorders for the unborn (termed as deterministic or non-stochastic effects, which have dose thresholds below which the effect does not occur). There is also an increased risk of cancer or leukaemia for prenatally exposed children (termed as stochastic effects).

Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is one of the most important and most meaningful imaging techniques which are used routinely and very successfully in radiological diagnostics for a variety of issues. Opposed to computed tomography (CT) it uses no ionizing radiation but different magnetic and electromagnetic fields. By meeting actual safety instructions at examinations there is no risk of adverse health effects for the patient. The following article gives a short overview into MRT and illustrates relevant safety aspects.

Benefit and risk of X-ray diagnostics

X-ray diagnostics is chosen by the doctor when other procedures such as laboratory tests, ultrasound or endoscopy would fail to provide a precise diagnosis. Radiology often is the first procedure to permit or confirm diagnosis or to specify findings.

Scintigraphy of a thyroid glandSource: Technical University of Munich, Clinic and Policlinic of Nuclear Medicine, Klinikum rechts der Isar

Diagnostic nuclear medicine

Patients in diagnostic nuclear medicine are given radioactive pharmaceuticals (radiopharmaceuticals) accumulating in organs and tissues in varying concentrations, depending on the pharmacological properties of the compound administered. Due to their radioactivity, the location and time of distribution within the body is detectable using proper measuring equipment, and thus can be visualised.

Ultrasound Diagnostics (UD)

Sonography is a frequently used imaging technique for medical diagnostics. Ultrasound diagnostics uses acoustic waves and not ionising radiation.

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