Purpose. Creation of pooled database of persons underwent computed tomography (CT) for assessing the risk of possible long-term consequences of diagnostic exposure to a low doses of ionizing radiation.

Material and methods. Archive protocols of computed tomography of Ozyorsk residents collected since the time of first using the CT in medical departments of Chelyabinsk region has been digitized, verified and integrated into an electronic database. Retrospective follow-up study provides the information on 22,705 CT examinations of Ozyorsk residents who underwent computed tomography during the period from 1993 to 2017.

Results. The total number of examined patients was 14894, while 70.1% of patients were single-time examined during the follow-up period. The maximum number of second examinations of one patient was 19. The most of CT protocols collected (61.5%) was represented by examinations of the head. The average effective dose for each examination was 3.2 mSv, and it’s maximum value did not exceed 50 mSv. The age of the exposed patients varied from 0 to 99 years, while the proportion of child CT was 6.5%. Vital status has been estimated for 47.8% of the patients to the end of 2017.

The completeness of the information collected in the database may be affected by cases of distant examinations of patients outside the Chelyabinsk region. However, it was assumed that such cases were rare. The lack of a unified national database for registering CT exposure of patients could lead to an underestimation of radiation burden of population.

Conclusion. The pooled database provides a unique source of information about an additional non-occupational ionizing radiation exposure. The data can be used to analyze the risk of exposure to low doses of diagnostic exposure among nuclear personnel and the population, and for the purposes of radiation-hygienic rationing as well.