Objective To systematically analyze the medical radiation exposure levels in a district of Ningbo City and to provide a scientific basis for the reasonable and effective control of medical radiation exposure. Methods Based on the radiological diagnosis frequency and dose information system, basic medical radiation exposure data were collected, such as radiation doses received by patients in various X-ray diagnostic examinations, from all 13 public medical institutions in a district of Ningbo City from January 1 to December 31, 2020. The data were analyzed for the percentage and collective effective dose of various diagnostic examinations, the distribution of examinations by sex and age, and the number of patients undergoing two or more examinations and their cumulative doses within multiple time intervals. Results Among medical X-ray diagnostic examinations in the district, the percentages of CT examination and routine photography examination were 50.88% and 47.93%, respectively, and the collective effective dose of CT examination accounted for 97.75%. By age and sex, the frequency of examination was the highest in the age group of 45-54 years, and the frequency of examination in the male was higher than that in the female before age 55. The annual effective dose for two patients exceeded 100 mSv. Conclusion In this study, CT examination accounted for up to 50.88% of all medical X-ray diagnostic examinations, and contributed 97.75% of the collective effective dose, highlighting the need for particular attention to the justification of medical radiation exposure from CT.

Objective With the increase in pet-owning households in China, veterinary clinics have increased at an annual rate of 19.86%. However, the management blind area that may exist in multi-department supervision has led to a significantly worse working environment of radiation workers in veterinary clinics than that of medical institutions. The purpose of this study was to understand the levels of occupational external exposure of radiation workers in veterinary clinics in China, analyze the occupational risks faced by radiation workers in veterinary clinics, contribute to the protection of the occupational health of radiation workers, and provide data and scientific basis for the formulation of national relevant regulations and standards. Methods The individual dose monitoring data of radiation workers in selected veterinary clinics in 2022 were obtained from the National Individual Dose Registration System. Results This study involved 1868 radiation workers from 1216 veterinary clinics in 28 provinces and municipalities in China. The maximum annual effective dose was 8.93 mSv, the annual collective dose was 536.77 man·mSv, the average annual effective dose was 0.29 mSv, and the median was 0.15 mSv. The largest proportion of individuals (94.5%) received a dose of less than 1.0 mSv, while 5.4% had doses ranging from 1.0 mSv to less than 5.0 mSv. For radiation workers with an annual effective dose of 1.0 mSv and above, the individual distribution ratio of radiation workers in veterinary clinics was significantly higher compared with those in medical institutions and industrial applications (P < 0.05). Conclusion The levels of occupational external exposure of radiation workers in veterinary clinics meet the requirements of national standards. However, attention should still be paid to the radiation protection of radiation workers in veterinary clinics. This includes enhancing the responsibility awareness of veterinary clinic owners, strengthening protection training for radiation workers, protecting the occupational health of practitioners, and preventing the occurrence of occupational radiation diseases.

Objective To propose a method for correcting the attenuation of positron emission tomography (PET) data in PET/magnetic resonance (MR) based on transmission scan, and to improve image quality, diagnostic accuracy, and lesion location accuracy. Methods In this study, the head phantom in the national standard GB/T 18988.1—2013 was used as the experimental model. The head phantom contained three 50 mm diameter cylindrical inserts filled with air, water, and solid teflon. The attenuation correction coefficients were calculated and analyzed based on transmission scan. Results With slice = 33 and theta = 0, the attenuation correction coefficient was the largest (about 7.5) when the coincidence line passed through the axis of the phantom. The spatial distribution of the attenuation correction coefficients clearly showed the positions of air insert and teflon insert, indicating that the attenuation correction coefficients calculated from transmission scan data were accurate. In the clinical verification experiment, the attenuation correction method based on transmission scan significantly improved the image quality and showed efficient attenuation correction. Conclusion This paper studied the attenuation correction method for PET data in PET/MR based on transmission scan. This method can improve the image quality. In the future work, the attenuation correction method of PET/MR will be further studied and optimized to facilitate clinical applications.

ObjectiveTo evaluate the clinical effectiveness and safety of Lianling Formula （连苓方） in the treatment of adolescent atopic dermatitis （AD） exacerbation stage with heart fire and spleen deficiency syndrome. MethodsNinety-two patients were randomly divided into a treatment group and a control group， with 46 cases in each group. Patients in the control group took oral ebastine tablets， and patients in the treatment group took Lianling Formula orally， and both groups used 0.03% topical tacrolimus for 4 weeks. Before and after treatment， the improvement of scoring atopic dermatitis index by 50% （SCORAD50） and 75% （SCORAD75）， scoring atopic dermatitis index （SCORAD）， visual analog scale （VAS）， traditional Chinese medicine （TCM） symptom score， the children's dermatology life quality index （CDLQI）， Athens insomnia scale （AIS） score of both groups were evaluated， and the adverse reactions in both groups were recorded. ResultsFour cases in the treatment group and five cases in the control group were dropped， and intention-to-treat analysis was used. Finally 46 cases in each group were included in the statistics. The SCORAD scores after treatment were lower than those before treatment， and the scores in treatment group were lower than those of the control group （P＜0.01）； the attainment rates of SCORAD50 and SCORAD75 after treatment in the treatment group were 80.43% and 47.83%， which were significantly higher than those in the control group of 63.04% and 26.09%， respectively （P＜0.05）. VAS scores， TCM symptom scores， CDLQI scores， and AIS scores were lower than those before treatment （P＜0.01）， and VAS scores， TCM symptom scores， and CDLQI scores of the treatment group were lower than those of the control group after treatment （P＜0.05 or P＜0.01）， while AIS scores were higher than those of the control group （P＜0.05）. The erythema， papule/edema， oozing/crusting， epidermal peeling， and dryness in the SCORAD scores of the treatment group after treatment were lower than those before treatment （P＜0.05 or P＜0.01）， and the erythema， papule/edema， oozing/crusting， and dryness of children in the control group were lower than those before treatment （P＜0.05 or P＜0.01）. The scores of erythema， oozing/crusting， and epidermal peeling in the treatment group after treatment were all lower than those in the control group （P＜0.05）. The scores of vexation， itching， dry mouth， poor appetite and irregular bowel movements in terms of TCM symptoms in the treatment group after treatment were lower than those before treatment （P＜0.01）， and the scores of itching， vexation， dark urine in the control group were lower than those before treatment （P＜0.05 or P＜0.01）. The scores of itching， dry mouth， poor appetite， irregular bowel movements， and dark urine in the treatment group after treatment were all lower than that in the control group （P＜0.05 or P＜0.01）. No adverse reactions occurred in both groups of children during treatment. ConclusionLianling Formula combined with topical tacrolimus can effectively improve the clinical symptoms of adolescent AD exacerbation with heart fire and spleen deficiency syndrome， and the formula is effective and safe in improving the children's skin lesions， reducing itching， relieving the accompanied TCM symptoms， and improving the quality of life.

Objective To propose a method for correcting the attenuation of positron emission tomography (PET) data in PET/magnetic resonance (MR) based on transmission scan, and to improve image quality, diagnostic accuracy, and lesion location accuracy. Methods In this study, the head phantom in the national standard GB/T 18988.1—2013 was used as the experimental model. The head phantom contained three 50 mm diameter cylindrical inserts filled with air, water, and solid teflon. The attenuation correction coefficients were calculated and analyzed based on transmission scan. Results With slice = 33 and theta = 0, the attenuation correction coefficient was the largest (about 7.5) when the coincidence line passed through the axis of the phantom. The spatial distribution of the attenuation correction coefficients clearly showed the positions of air insert and teflon insert, indicating that the attenuation correction coefficients calculated from transmission scan data were accurate. In the clinical verification experiment, the attenuation correction method based on transmission scan significantly improved the image quality and showed efficient attenuation correction. Conclusion This paper studied the attenuation correction method for PET data in PET/MR based on transmission scan. This method can improve the image quality. In the future work, the attenuation correction method of PET/MR will be further studied and optimized to facilitate clinical applications.

Objective:To estimate and analyze the levels of occupational exposure of aircrews in China, and to provide scientific basis for strengthening occupational health management.Methods:Through the FlightAware website, the flight data were collected of a total of 104 routes flying between airports with large passenger volume in China. Four kinds of cosmic radiation dose estimation programs CARI, SIEVERT, PCAIRE, and JISCARD-EX were compared and analyzed from the aspects of covering the number of airports in China, program user experience and example calculation of airline effective dose. Based on route logs, CARI-7A was applied to estimate the levels of occupational exposure of Chinese aircrews to cosmic radiation.Results:The difference in the effective doses calculated by use of these four cosmic radiation dose estimation programs for the routes with different solar activity levels was statistically significant ( M=7.52-180.98, P<0.05). The annual effective dose estimated by PCAIRE for 68 routes from 2014 to 2021 was significantly higher than that estimated by CARI-7A ( Z=2.52, P<0.05). Based on CARI-7A, the annual effective doses from cosmic radiation to aircrews in China from 2014 to 2021 were estimated, being 1.26 (0.57-2.35) mSv for flight attendants and 1.03 (0.47-1.92) mSv for pilots. The effective dose from cosmic radiation to aircrews on a single flight on some high-frequency routes in China ranged from 0.57 to 6.88 μSv. Conclusions:The level of occupational exposure of Chinese aircrews to cosmic radiation meets the requirements of national standards, but is higher than that of occupational exposure from medical and industrial applications of radiation, so it is still necessary to further strengthen the mamagememt of occupational exposure and occupational health of aircrews.

Objective To develop a Psychological Birth Trauma Assessment Scale and to test its reliability and validity.Methods Through literature review,semi-structured interview,expert conference,Delphi expert enquiry and preliminary investigation,a pre-test scale was formed.From March to May 2023,postpartum women from 38 hospitals of different levels in 15 provinces(Jiangsu,Anhui,Zhejiang,Fujian,Tibet,and Shanghai,etc.)were conveniently selected for investigation.The sample size of the first-round survey was 547,which was used for reliability and validity test.The sample size of the second-round survey was 550,which was used for confirmatory factor analysis.Results The psychological birth trauma assessment scale consisted of 2 parts,with a total of 29 items in 6 dimensions.The intrapartum feeling part included 4 dimensions,with a cumulative variance contribution rate of 63.992％,and the postpartum effect part included 2 dimensions,with a cumulative variance contribution rate of 68.208％.The content validity index of the scale was 0.947,and the content validity index of each item was 0.809～1.000.The total score of the scale and the scores of each dimension were significantly negatively correlated with the total score of the calibration scale(r=-0.784～-0.533,P＜0.001).The total Cronbach's α coefficient was 0.941,and the split-half reliability coefficient was 0.883.Confirmatory factor analysis showed that the main evaluation indicators were all within the acceptable range.Conclusion The Psychological Birth Trauma Assessment Scale has good reliability and validity,and it can be used as an assessment tool for the degree of maternal psychological birth trauma.

Objective To analyze the factors influencing the levels of occupational exposure in medical radiation workers in China, and to provide a scientific basis for determining the key points of radiation protection in the medical sector. Methods The individual monitoring data on occupational external exposure in medical radiation workers in 2021 were collected from the “National Individual Dose Registry”. The Chi-squared test and logistic regression were used to analyze the factors influencing the levels of occupational exposure in medical radiation workers. Results The Chi-squared test showed that gender, occupational category, medical institution category, region, number of radiation workers per thousand population, and regional per capita GDP were significantly associated with occupational exposure in medical radiation workers exceeding the annual effective dose of 5 mSv and an annual effective dose limit of 20 mSv (χ² = 21.456−262.329, 7.601−78.650, P < 0.05). The logistic regression analysis further showed that gender, occupational category, region, and number of radiation workers per thousand population were factors influencing the occupational exposure in medical radiation workers exceeding the annual effective dose of 5 mSv (χ² = 14.621−170.857, P < 0.05); gender, occupational category, region, and regional per capita GDP were factors influencing the occupational exposure in medical radiation workers exceeding the annual effective dose of 20 mSv (χ² = 5.401−48.709, P < 0.05). Conclusion Male radiation workers in interventional radiology and in central China have high risks of exceeding annual effective doses of 5 and 20 mSv. Moreover, high number of radiation workers per thousand population and regional per capita GDP are associated with low risks. Medical institutions should maintain a sufficient number of radiation workers and strengthen training on radiation protection knowledge for male and interventional radiology workers to enhance their radiation protection awareness. Investigation of the factors contributing to the high occupational exposure in central China should be intensified, and targeted effective measures should be conducted to reduce the occupational exposure in medical radiation workers.

Objective To establish a model for estimating the eye lens dose of the first operator in interventional therapy based on the Monte Carlo simulation, and to provide a scientific basis for the rapid and accurate evaluation of the eye lens dose for radiation workers in interventional therapy. Methods Based on the MIRD phantom and eye model for adult Chinese males, the MCNPX program was used to establish the physical model to calculate the spatial distribution of radiation field and eye lens dose for the first operator. A GR200 Type A LiF (Mg, Cu, P) thermoluminescence dosimeter was used for experimental measurement to verify the simulation results. Results Monte Carlo simulation and experimental measurements showed that the spatial distribution of radiation field was symmetrical. Compared with the measured doses, the errors of the simulated eye lens dose of the first operator were between −8.3% and 7.3%. The dose of the left eye lens was higher than that of the right eye. Conclusion The Monte Carlo model constructed in this study initially realizes the simulation of eye lens dose of the first operator in interventional therapy. In the future, the model will be further optimized based on irradiation parameters such as exposure time, tube voltage, tube current, and projection direction used in clinic practice, so as to more accurately evaluate the eye lens dose of interventional therapy staff.

Objective:To explore artificial intelligence technology and propose an algorithm for automatic identification of dicentric chromosomes to realize fast and high-throughput biodosimetry. In order to solve the time-consuming and laborious problem of manual analysis of dicentric chromosomes.Methods:Combining artificial intelligence technology and image processing technology, based on MATLAB software, algorithms like image preprocessing, threshold segmentation algorithm, binarization processing, area identification algorithm, convolutional neural network algorithm and double centripetal recognition algorithm were applied. A fuzzy membership function was defined to describe the degree of each chromosome belonging to a dicentric chromosome, and the discrimination threshold was set to realize the automatic identification of dicentric chromosomes.Results:Through the test on 1 471 chromosome images, compared with manual recognition, the detection rate of dicentric chromosomes cells of this algorithm reached 70.7%.Conclusions:This algorithm method carries out a preliminary study on the automatic identification of dicentric chromosomes with good result.