Radiation safety

From the point of view of radiation safety, methods that do not use ionizing radiation, ultrasound and MRI, have undoubted advantages.

The safety of the impact on the body of a strong magnetic field used in MRI, strictly speaking, still requires clarification, given that the method has been used relatively recently and a great deal of experience has not yet been accumulated. Therefore, it is considered undesirable to use MRI during pregnancy, especially in the first third of it. MRI is potentially dangerous and is therefore contraindicated in patients with implanted rhythm drivers, metallic foreign bodies sensitive to the magnetic field.

Among the methods based on the use of ionizing radiation, radionuclide imaging is the most safe, in which (especially when using short-lived isotopes) the dose of irradiation is tens or hundreds of times smaller than in radiography and CT. The most dangerous is CT, at which the dose of ionizing radiation is significantly higher than in a conventional X-ray study, and directly depends on the number of cuts performed, that is, increasing the resolving power leads to an increase in the radiation load.

Possible harmful effects of ionizing radiation on the body include two large groups - deterministic and stochastic. Deterministic effects occur if the dose of radiation is above a certain threshold value, and their severity increases with increasing dose. First of all, rapidly dividing cells, tissues with intensive metabolism are affected: epithelium, red bone marrow, reproductive and nervous systems. Deterministic effects occur in the near future after irradiation, are well suited to study, so effective methods for their prevention have been developed to date. First of all, this is the use of radiation doses for diagnostic purposes, which are substantially lower than thresholds. Thus, the threshold erythematous dose of X-ray radiation is achieved when 10,000 X-rays, or 100 KT, are performed, which is never the case in real conditions.

The difference between stochastic effects and deterministic ones is that the dose of irradiation depends not on the severity, but on the probability of complication development. These include carcinogenesis and genetic mutations. The danger of stochastic effects lies in the fact that they do not know the dose threshold, therefore any study using ionizing radiation is associated with a risk of complication, even with a minimum dose of radiation and the use of protective equipment. To reduce the radiation exposure, protective shielding devices are used, reduce the time of irradiation and increase the distance between the radiation source and the patient. However, these measures only reduce the probability of stochastic effects, but do not completely eliminate it. Since any research with ionizing radiation can potentially lead to carcinogenesis and mutations, and the radiation doses obtained from different studies are summarized, it is recommended to limit the use of these types of radiation diagnostics as much as possible, to perform them according to strict indications. CT should only be performed when other available imaging techniques can not provide the necessary information; It is necessary to strictly limit the area of interest and clearly justify the number of sections produced.

[1], [2], [3]