Probable dose loads to cosmonauts in a short-term lunar mission including the transit and stay on the surface were estimated using actual measurements and model calculations. It was found that doses of radiation received in a 21-day mission with a 14-day stay on the Moon in the period of minimal solar activity will make about 130 mSv; in the period of solar maximum and in case of a solar event radiation doses may reach 9–12 Svwith the maximum admissible dose of 250 mSv over a month. Increase of mass thickness of radiation shield of the command module from 10 to 20 g/cm2 (aluminum equivalent) and of the EVA spacesuit from 0.2 to 0.5-1.0 g/cm2 (aluminum equivalent) can reduce 1.4 times the total dose to cosmonauts in the period of solar minimum. Minimization of crew radiation levels requires a consideration of the solar activity forecast in order to choose the launch "windows" when high-energy electrons flow in the Earth's external radiation belt is minimal, and space weather along the route to the Moon.

Background: The issue of assessing the features of factors affecting the formation of radiation doses of astronauts while in orbit of the Moon and on its surface remains insufficiently studied, which is important for ensuring the anti-radiation safety of astronauts on lunar missions. Purpose: To analyze the factors influencing the formation of the radiation dose of astronauts at the stage of finding the spacecraft in orbit of the Moon and the lander on its surface. Material and methods: The features of the dose load levels on astronauts at the stages of the Moon’s orbit and on the Moon’s surface are analyzed and generalized, calculation methods are used taking into account the orbit of the spacecraft around the Moon, the anti-radiation properties of the materials of the lander and spacesuit and the time spent in them during a short-term lunar mission. Results: The total radiation doses of astronauts for 14 days, calculated according to dosimetric measurements during the years of low solar activity (2009 and 2018‒2019), are 19.5‒23.2 mSv for astronauts staying in a spacecraft in lunar orbit, and from 22,7 to 24,0 mSv for astronauts on the Lunar surface, depending on the mass thickness of the protection at the maximum permissible 250 mSv for 1 month. An increase in the mass thickness of the anti-radiation protection of the lander in the equivalent of aluminum from 1.5 to 3-5 g/cm2 and the lunar spacesuit in the equivalent of aluminum from 0.2 to 0.5‒1 g/cm2 will reduce the total radiation dose of astronauts no more than 1.3 times during a 14-day stay on the surface of the moon. The results indicate that in order to minimize the radiation doses that astronauts receive during a lunar mission, it is important to take into account the forecast of solar activity in order to optimize the launch time of the spacecraft in the «windows» with minimal levels of radiation exposure. Conclusion: When predicting radiation hazard levels for astronauts during a short-term lunar mission, it is necessary to assess the levels of exposure to cosmic ionizing radiation both in the orbit of the Moon, depending on the lunar trajectory of the spacecraft, and on the surface of the Moon, taking into account the time spent in the lunar module and in a spacesuit, as well as levels of solar activity. It is important to take into account the analyzed features of the formation of cosmonauts’ radiation doses while orbiting the Moon and on its surface when predicting the time limits of the lunar mission, anti-radiation protection of astronauts and their compliance with the regulatory limits of exposure.

Purpose: To estimate the potential of imaging methods in the diagnosis of non-alcoholic fatty liver disease (NAFLD) based on the example of a clinical case. Material and methods: A 42 years-old man with suspected of NAFLD, by the clinical and laboratory tests results, underwent a quantitative assessment of fatty hepatosis using radiodiagnosis imaging methods. We used US “liver protocol” with attenuation imaging technique (ATI), shear wave elastography (SWE), shear wave dispersion imaging (SWD), computed tomography (CT) with quantitative and qualitative assessment using the liver-spleen index (CTL-S); MRI with application that provides volumetric whole-liver fat fraction (FF) measurements by proton density (PDFF), on the basis of IDEAL IQ program. The morphological verification of liver biopsy was also performed. Results: All imaging method used in this clinical case showed severe degree of fatty hepathosis, that correlated with biopsy of liver. In repeated studies, on the background of treatment, the quantitative indicators of all imaging methods had a similar dynamics of reduction of the degree of fatty hepatosis. Conclusion: The clinical case of verified acute steatohepatitis shows the possibilities of its diagnostics by means of the radiation modalities. We used US with ATI, SWE и SWD, CT with CTL-S, MRI with FF that demonstrated high diagnostic efficiency for determination fatty hepatosis and the possibility of its quantification. These technologies are suitable for widespread implementation into clinical practice providing good diagnostic accuracy. CT associated with higher doses of radiation is not considered to be the basic method of choice for diagnosing NAFLD, but still may provide a physician with necessary information to determine further treatment strategy.

Analysis of the air accident rates of MQ-1 Predators and MQ-9 Reapers from the Drone Crash Database in the period from 2001 till 2021 (12 countries, 174 accidents total) disclosed major factors, including human, for accidents. The main reason was structural faults and manufacturing defects due to, probably, long time in service. Frequency of accidents due to errors of experienced pilot-operator's varied between 19.4% and 22.9 % and due to errors in the course of skill training, 60–64.7 %. To reduce the accident rate, pilot-operators need to be trained on cutting-edge VR simulators and challenged by atypical stress situations such as multiple causation.

OBJECTIVE to analyze radiation exposure due to computed tomography (CT) of brain, chest, abdomen and pelvis in a large multi-field federal hospital and feasibility of low-dose CT-examinations. MATERIAL AND METHODS Retrospective analysis was performed using data from electronic patient records and PACS from a single multi-field hospital. Data were obtained from 1626 records of patients (794 men, 832 women; age range 17-93) scanned with 3 MDCT during one year. CT-examinations of good quality were selected, volumetric CT dose index (CTDI) and dose-length product (DLP) were collected for each of them. The effective doses (ED) were calculated using the normalized coefficients according to Russian Guidance. RESULTS. Number and structure of CT-examinations for the years 2012-2014 in a multi-field hospital were analyzed. The mean effective dose (M ± m) values with/without contrast medium (respectively), according to anatomical areas were as follows: brain--2.34 ± 0.03/3, 52 ± 0.23, chest--4.83 ± 0.11/11.02 ± 0.82, abdomen-pelvis--9.81 ± 0.40/36.6 ± 1.17, chest-abdomen-pelvis - 12.41 ± 0.79/35.63 ± 1.81 mSv. CONCLUSION. Results of this study give an example of CT dose values and distribution in a multi-field hospital. They are compa- rable with reference levels published of other authors. This expe- rience should be expanded for creation of CT national reference values and for co-operation with international initiatives (EUROSAFE projects).

Objective – to analyze radiation exposure due to computed tomography (CT) of brain, chest, abdomen and pelvis in a large multifield federal hospital and feasibility of low-dose CT-examinations. Material and methods. Retrospective analysis was performed using data from electronic patient records and PACS from a single multi-field hospital. Data were obtained from 1626 records of patients (794 men, 832 women; age range 17–93) scanned with 3 MDCT during one year. CT-examinations of good quality were selected, volumetric CT dose index (CTDI) and dose-length product (DLP) were collected for each of them. The effective doses (ED) were calculated using the normalized coefficients according to Russian Guidance. Results. Number and structure of CT-examinations for the years 2012–2014 in a multi-field hospital were analyzed. The mean effective dose (M±m) values with/without contrast medium (respectively), according to anatomical areas were as follows: brain – 2,34 ± 0,03/3,52 ± 0,23, chest – 4,83 ± 0,11/ 11,02 ± 0,82, abdomen-pelvis – 9,81±0,40/36,6±1,17, chest-abdomen-pelvis – 12,41 ± 0,79/35,63 ± 1,81 mSv. Conclusion. Results of this study give an example of CT dose values and distribution in a multi-field hospital. They are comparable with reference levels published of other authors. This experience should be expanded for creation of CT national reference values and for co-operation with international initiatives (EUROSAFE projects).

Poster: ECR 2015 / C-1227 / Analysis of annual radiation exposure due to CT in a single federal public hospital in Russia by: E. Matkevich, V. Sinitsyn ; Moscow/RU

Purpose of the investigation was to make prognostic estimations of reductions in somatic morbidity and temporal disability, and tumor pathology using low-dose computer tomography (CT) scans and to compare with standard protocols. Mean effective radiation doses were determined based on the results of 1627 diagnostic CT investigations made in 2012-2014 at the Treatment and Rehabilitation Center of the Russian Ministry of Health. Low-dose CT scans of the head and thoracic, abdominal and small pelvis organs were obtained on a GE Discovery CT750 HD, and with the help of the ASIR and MBIR algorithms of iterative reconstruction. In comparison with a standard dose, a single CT scan with a dose reduced by 10-12 mSv predicts a decrease in total morbidity by 0.84-5.52% and temporal disability by 0.55-1.65% per 100 employees over a year; total risk of tumors and genetic effects reduced in 5 to 10 times, which may be equal to 40-90 cases per 100,000 of 30 y.o. males.