О ВЛИЯНИИ МАЛЫХ И СРЕДНИХ ДОЗ РАДИАЦИИ НА СТРУКТУРУ ПРОВОДЯЩИХ ПУТЕЙ ГОЛОВНОГО МОЗГА У ЛИКВИДАТОРОВ ПОСЛЕДСТВИЙ АВАРИИ НА ЧАЭС В ОТДАЛЕННОМ ПЕРИОДЕ (ПО ДАННЫМ ВЫСОКОПОЛЬНОЙ РУТИННОЙ И ДИФФУЗИОННО-ТЕНЗОРНОЙ МАГНИТНО-РЕЗОНАНСНОЙ ТОМОГРАФИИ)

Abstract

To evaluate correlation between brain structural damages and radiation exposure level for the Chernobyl nuclear power plant accident liquidators, routine and diffusion tensor magnetic resonance imaging methods are efficient to visualize and evaluate those damages; it is also important to compare magnetic resonance imaging data of liquidators with results, received for people of the same age and the same stage of cerebral vascular disease (the discirculatory encephalopathy of I and II stage), but who did not participate in the Chernobyl accident liquidation and did not suffer from other liquidation factors and radiation catastrophe aftermaths. As a result, the Chernobyl accident liquidators group (49 subjects) and group of control (50 subjects) were examined with routine magnetic resonance imaging methods and standard protocols. In addition, the innovative method of diffusion tensor magnetic resonance imaging was applied to examine 11 cerebral tracts, bilaterally (22 tracts in both hemispheres) for every subject of the research. It was for the first time when diffusion tensor magnetic resonance imaging was applied to conduct visual analysis of polymorphic brain changes for the Chernobyl accident liquidators and special research conducted to find correlation between fractional anisotropy coefficient and radiation exposure for these patients. The results of diffusion tensor magnetic resonance imaging indicated no statistically significant (p > 0,05) difference in the level of cerebral morphological changes and between average fraction anisotropy coefficient value in any cerebral tract for both sub-groups of liquidators with different level of irradiation: 28 subjects, who were exposed by low and very low radiation doses (0–100 micro-Sv, sub-group A) and 21 subjects, who were exposed by mean radiation doses (100–1000 micro-Sv, sub-group B). However, comparing diffusion tensor magnetic resonance imaging results of control group and liquidators group, statistically significant (p < 0,05) reduction of average fraction anisotropy coefficient was detected in frontal and temporal lobes. It proves significant micro-structural damages of mentioned brain areas caused by different factors of the Chernobyl accident liquidation.