CS Here you will find answers to the most frequently asked questions concerning nuclear medicine, examinations, therapy and radiopharmaceutical preparations. Further information is also available at
What does nuclear medicine deal with?
Nuclear medicine is a medical discipline used mainly for diagnostics, but also for therapy using radioisotopes. It is one of the non-invasive diagnostic methods. Unlike diagnostic radiology, which is based only on anatomical knowledge, nuclear medicine also makes it possible to obtain functional information about organs or metabolism. Diagnostics in this field allow the extent of a disease or its progression to be determined even at an early stage, which significantly improves the patient's prognosis.
Which disciplines does nuclear medicine most often cooperate with?
Nuclear medicine enables examinations across a wide range of medical disciplines – from paediatrics through internal medicine to psychiatry. The most widespread use today and in the future is in cardiology, neurology and oncology.
What do in vitro methods deal with?
In vitro methods such as radioimmunoassay, etc. are used to determine the concentrations of complex biological substances in blood serum – hormones and specific antigens (so-called tumour markers, etc.) – whose values are compared with reference ranges.
Are nuclear medicine methods used only as a diagnostic tool?
Nuclear medicine is also used in therapy, e.g. in the treatment of hyperthyroidism or thyroid cancer, blood imbalances, palliative treatment of bone cancer, radiosynoviorthesis and other therapeutic applications.
How is an examination carried out using nuclear medicine methods?
A very small amount of radiopharmaceutical, needed to obtain good-quality image information, is usually administered into the patient's vein. Depending on the type of examination, image acquisition takes from a few minutes to 1.5 h; sometimes it is performed immediately, at other times after a time interval following the injection. In some cases imaging is performed several times at intervals.
What is the radiation burden on the body during an examination?
The radiation burden of nuclear medicine methods is comparable to, or lower than, that of X-ray examinations.
Can an examination be performed during pregnancy?
If there is any possibility that the woman is pregnant, it is essential to inform the medical staff before the radiopharmaceutical is administered. Certain additional protective measures need to be discussed. After the examination there is no need to avoid becoming pregnant.
How compatible are nuclear medicine examinations and breastfeeding?
Some radioactive substances are excreted into breast milk. It is essential to check with the physician of the nuclear medicine department whether breastfeeding needs to be interrupted and, if so, for how long.
Gamma camera (scintillation camera)
It consists of a detection system used to register the radiation emitted by radiopharmaceuticals administered to the patient.
In vivo examination
An imaging examination using radiopharmaceuticals administered directly to the patient.
In vitro examination
A laboratory immunoassay examination to measure the levels of hormones, tumour markers or vitamins in samples of body fluids.
Tumour markers
Substances produced by malignant cells or by the body in response to tumour growth. They differ from substances produced by normal cells either qualitatively (tumour-specific; normal cells do not produce them) or quantitatively (tumour-associated; also present in normal cells). They are antigens located on the surface of membranes, enzymes of metabolic pathways, or fragments of cytoplasmic structures released into the surroundings when cells die. They can be detected as substances circulating in the blood or other body fluids.
Nuclide
A set of atoms that have the same number of protons and nucleons.
Planar scintigraphy
It uses the detection of single-photon emitters and provides a two-dimensional image of an organ and the distribution of the radiopharmaceutical, which often corresponds to changes in the organ's metabolism.
PET
Positron emission tomography, in which a radiopharmaceutical with a very short half-life is administered to the patient before the examination. PET uses radiopharmaceuticals that produce positrons when they decay – so-called beta decay. Soon after it is created (within the order of millimetres, which it travels in a few nanoseconds), a positron annihilates with an electron that was in its vicinity. Both the positron and the electron disappear, and from the site of annihilation two photons of annihilation radiation with an energy of 511 keV fly off at a straight angle. The simultaneous interaction of these photons in the detectors of the scanning ring can be recorded by a so-called coincidence detector. From a large number (up to several hundred thousand) of such captures, a tomographic image of the examined person can then be reconstructed by a computational algorithm.
Radiopharmaceutical
A chemical compound containing a radionuclide with the appropriate properties.
Radionuclide
An unstable nuclide undergoing nuclear transformation.
Scan – scintigraphic image
The image output of information processed by mathematical procedures from the raw data provided by the relevant examination method.
SPECT
Single-photon emission computed tomography, which allows the reconstruction of slices in various planes, including 3D imaging.
