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  • 28 April 2018 Volume 27 Issue 2
      
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  • Comparison of calculated lung retention of 239Pu based on different human respiratory tract models
    CHEN Qianlan, LUO Zhiping, XIA Yihua
    2018, 27(2): 97-101. https://doi.org/10.13491/j.issn.1004-714x.2018.02.001
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    Objective To develop a software program for calculating lung retention calculation based on the Human Respiratory Tract Model (HRTM) recommended in ICRP 130, and compare its results with the program based on the HRTM in ICRP 66.Methods The software programs were compiled by using the Matlab Simulink module. Taken the inhalation of 239Pu as an example, its lung retention was calculated for three absorbing types by using the two models.Results For S and M absorbing type of aerosols, the long term lung retention predicted with the HRTM in ICRP 130 was more than twice as high as that predicted with the HRTM in ICRP 66, and the difference between the two models was more obvious for S absorbing type than for M absorbing type, while for the short and middle term retentions, the values predicted by the two models were close to each other. For the F absorbing type of aerosol, the clearance of lung retention predicted with the HRTM in ICRP 130 was much more slowly than that predicted by the HRTM in ICRP 66.Conclusion A software program based on the HRTM in ICRP 130 has been developed for calculation of lung retention of radioactive aerosols. The results calculated with different HRTMs are different, further studies are needed.
  • Discussion on radiation protection and critical control techniques on 125I seed implantation
    ZHANG Zaoqin, FU Qiang, GENG Jiwu, XU Zhiqiang, WANG Meixia, XIA Bing
    2018, 27(2): 102-105. https://doi.org/10.13491/j.issn.1004-714x.2018.02.002
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    Objective To explore the occupational risk factors and radiation levels in the process of iodine-125 (125I) seed implantation, and discuss the key control techniques.Methods Taking the 5 tertiary level general hospitals performing 125I seeds implantation project as the research object, the field hygienic survey, environmental radiation monitoring and personal dose monitoring were carried out. Combined with the characteristics of source items and radiological hygiene management experience, and according to the principle of hazard analysis and critical control point (HACCP), the key control points of 125I seed implantation process were discussed.Results The ambient dose equivalent rates of 125I seeds package, implantation therapeutic room and special wards ranged from the background level to 1.80 μSv/h, they were all less than 2.5 μSv/h. The annual effective dose of 35 staff ranged from 0.20 to1.80 mSv/a, with an average of 0.42 mSv/a.Conclusion Both the radiation level of the workplace and exposure dose of staff were in accord with the national standard limits. According to the critical control points, the key control measures should be implemented in the practice of 125I seed implantation.
  • A study on the effective doses received by patients undergone esophageal scanning by using single-source and dual-source CT
    YU Jinyu, ZHANG Hongwei, ZHANG Lin, YANG Shuhui, GAO Zeyu, MIN Nan, ZHU Jianguo
    2018, 27(2): 106-108,113. https://doi.org/10.13491/j.issn.1004-714x.2018.02.003
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    Objective By aid of the phantom experiments, this study aims to investigate the effective doses received by patients undergone esophageal scanning by using single-source and dual-source CT in different scanning modes.Methods According to ICRP 103 publication, TLDs were placed in the 38 target holes of different organs or tissues of the phantom to measure the absorbed doses. The experiments were performed in the same scan condition by the single-source 64 slices CT, the dual-source 64 slices CT with single energy mode and the dual-source 64 slices CT with dual-energy mode. The effective dose was calculated based on the measured organ or tissue doses and their corresponding tissue weighting factors.Results The ranges of organ or tissue absorbed doses were 0.126~329.7 mGy, 0.114~317.8 mGy and 0.123~321.2 mGy for dual-source 64 slices CT in dual-energy mode, dual-source 64 slices CT in single energy mode and single-source 64 slices CT, respectively. The lowest organ adsorbed dose was found in gonad and the highest was in bone tissue. The effective doses were estimated to be 26.9 mSv, 26.1 mSv and 26.8 mSv for the three groups, respectively.Conclusion The effective doses of three scan modes are nearly the same. In this regard, in selecting the different modes for esophageal scanning, the difference of patient's dose can be ignored. Meanwhile the out-field of sensitive organ or tissue should be protected with the purpose of reducing the organ or tissue dose and the effective dose.
  • Application of non-invasive inhalation anesthesia precision thoracic irradiation device in a mouse model
    GENG Jiwu, LIU Hao, CAO Liji, LU Shun, HAN Dong, CHEN Ming, CHEN Longhua, ZHOU Cheng
    2018, 27(2): 109-113. https://doi.org/10.13491/j.issn.1004-714x.2018.02.004
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    Objective To develop a large scale, practical and cost-effective method for precision thoracic irradiation in a mouse model, and to popularize this important radiobiology model in many fields.Methods A total of 12 C57BL6 female mice (8~10 weeks old) were used for quantitative assessment of pulmonary anatomical parameters and radioactivity range by using three-dimensional reconstruction of micro-CT images. Integrating non-invasive inhalation anesthesia standardized thoracic cavity exposure and multiple fixation technology, a specially designed mice holder was established to facilitating whole thoracic irradiation (WTI) by a clinical Linac system.Results The parameters of lung and neighbor structures were measured in coronal and sagittal views of reconstructed CT images. Taking the breath motion into account, the determined anatomical parameters were utilized to defining the accurate irradiation field and being labeled on the specially designed device for positioning purposes. This device can be roughly divided into two parts:a mouse fixation frame and an anesthesia ventilation system. The fixation component was available for 10 mice to be properly fixed with elastic bolt at the same time. An isoflurane mixed gas was administered through the anesthesia mask to ensure that the mice were deeply anesthetized and stable throughout the irradiation course.Conclusion The present mice WTI cassette is incorporated with multiple functions such as inhalation anesthesia, immobilization and accurately positioning, which can significantly increase the accuracy, simplicity, safety, stability, and high efficiency of thoracic irradiation experiments.. It reduces remarkably the experimental cost and less depends on the expensive small animal IGRT system. This device is therefore of practical significance in the field.
  • A case analysis on diagnosis and identification of radioactivity occupational diseases
    LI Qinghua, ZHU Xiaoming, ZHANG Jinlong
    2018, 27(2): 114-116,119. https://doi.org/10.13491/j.issn.1004-714x.2018.02.005
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    Objective Through the controversy in the diagnosis and identification of radioactive occupational disease in one case, the idea of radiological occupational disease diagnosis was discussed.Methods The inconsistent conclusion in diagnosis and identificatino of this case was demonstrated.Results The case was eventually diagnosed as chronic radiation skin damage.Conclusion The diagnosis and identification of radioactivity occupational diseases is with the disease as the center, and the conclution is according to its special pathological changes and clinical manifestations combined with the history of professional exposure.
  • Analysis of reasons for the missing of some required examination items in the health examination of population exposed to vocational radiation
    ZHAO Xuemei, LI Ye, MA Shaoyuan, WANG Wenming
    2018, 27(2): 117-119. https://doi.org/10.13491/j.issn.1004-714x.2018.02.006
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    Objective To grasp the implementation of required examination items and missing examination items,enhance the quality of health supervision and assessment works, control the deterministic effect of radiation workers better,reduce the occurrence rate of stochastic effect and alleviate the vocational radiation injury of radiation workers by carrying out heath examination for population exposed to vocational radiation.Methods 1116 radiation workers in Qinghai in 2016 were chosen, including those who operate medical ordinary X-rays radiography, CT, interventional therapy, nuclear medicine, radiotherapy and other radiological equipment in non-medical units, for the statistical analysis of their health examination data.Results The highest examination missing rate was found in X-ray chest film examination (56.8%), which was followed by ophthalmological slit-lamp examination (37.0%), laboratory examination (11.2%), electrophysiological examination (5.8%) and internal medicine examination (0.3%). Among the population of different types of work exposed to vocational radiation, workers from CT department had the highest missing rate of X-rays chest film examination (84.9%), the radiotherapy personnel had the highest missing rate of ophthalmological slit-lamp examination (51.9%), the nuclear medical personnel had the highest missing rate of laboratory examination (14.8%), CT department workers had the highest missing rate of electrophysiological examination (9.2%). it is worth-noticing that internal medicine examination had the lowest examination missing rate. Among the general population, the county and district-level medical units had the highest examination-missing rate (27.1%) while individual clinics and hospitals had the lowest (11.6%).Conclusions The missing of required health examination items fails to comprehensively reflect the health conditions of radiation workers and judge whether these workers should continue with their works. The incomplete medical examination reports directly affect the assessment of radiation places and the control over the occurrence of deterministic effect of radiation workers and the reduction of occurrence rate of stochastic effect.
  • Comparative study of liver and kidney health among radiation workers in city, county and township hospitals
    LIU Yinyin, LIU Gang, LI Ye, ZHANG Rong, NIU Limei, WU Xiaoqin
    2018, 27(2): 120-123. https://doi.org/10.13491/j.issn.1004-714x.2018.02.007
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    Objective To study the status and differences of liver and kidney health among radiation workers in city, county and township hospitals.Methods Selecting radiation workers from city, county and township hospitals as the research objects, collecting occupational health examination data from 2015 to 2016, analyzing the results of B-ultrasound of liver, gallbladder and kidney, liver and kidney function test results, and routine urinalysis results.Results The abnormal detection rate of gallbladder B-ultrasound in township hospitals was less than in county hospitals, and there was a significant difference (P<0.05); compared with township hospitals and county hospitals, compared with township hostpitals and city hospitals, compared with county hospitals and city hospitals, abnormal detection rate of alanine transaminase(ALT) was significantly different (P<0.05); abnormal detection rate of total bilirubin(TBIL) in township hospitals was significantly higher than in county hospitals (P<0.05); abnormal detection rate of TBIL in county hospitals was significantly less than in city hospitals(P<0.05); abnormal detection rate of direct bilirubin(DBIL) in township hospitals was significantly higher than in county hospitals and in city hospitals(P<0.05); abnormal detection rate of creatinine(CREA) in township hospitals was significantly higher than in county hospitals and in city hospitals(P<0.05);abnormal detection rate of routine urinalysis in township hospitals was significantly higher than in county hospitals (P<0.05); abnormal detection rate of routine urinalysis in county hospitals was significantly less than in city hospitals (P<0.05).Conclusion The liver and kidney health status of radiation workers in township hospitals is relatively poor compared with that of county and city hospitals.
  • Survey of students and teachers' perception on nuclear and radiation in Beijing
    CHENG Xiaoqing, LI Xiaoliang, SUN Quanfu, LEI Cuiping
    2018, 27(2): 124-128. https://doi.org/10.13491/j.issn.1004-714x.2018.02.008
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    Objective To investigate the attitude and perception of the radiation risk among students and teachers in some districts of Beijing, as well as the related influencing factors.Methods Stratified cluster random sampling and on-site anonymous questionnaire survey were conducted.47 questions about basic information, perception and attitude on nuclear and radiation, and the related influence factors were included in the questionnaire. Rate and proportion were used for statistical description. Chi-squared test were used for comparison between different groups. Multiple linear regression was used for multiple-factor analysis.Results A total of 1937 effective questionnaires including 1038 students and 899 teachers were collected. Among 10 questions about the perception and attitude on nuclear and radiation, numbers of correctly answered questions for teachers and students were 7.58 and 6.61.This result showed teachers had higher level of perception than students(t=-10.93,P<0.05). Meanwhile, numbers of correctly answered questions for male and female were 7.38 and 6.80 (t=6.30,P<0.05), which showed male knew better than female. Most subjects (72.06% of students and 85.21% teachers) were eager to learn nuclear and radiation information, knowledge from expert through television and Internet was preferable.Conclusions Publicity and education should be strengthened to improve students' nuclear and radiation knowledge. In order to promote nuclear and radiation perception of public and sustainable development of nuclear energy, more pointed and preferable measures should be considered to publicize the related knowledge.
  • Evaluation of safety-cognition effect of ionizing radiation to non-radiation staff on conception of knowledge, attitude, belief and practices
    JI Hao, ZHANG Jing, SHEN Qing
    2018, 27(2): 129-132. https://doi.org/10.13491/j.issn.1004-714x.2018.02.009
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    Objective To analyze the effect of training and education on radiation protection to non-radiation staffs in hospital based on conception of knowledge, attitude, belief and practices (KABP), and to provide reference for effective cooperation between clinical departments and nuclear medicine department.Methods Questionnaire surveys were performed before and after training and management intervention to staff who were closely contacted with patients undergone radionuclide examination. The questionnaire was designed on the basis of KABP, including four aspects:nuclear and radiation knowledge, characteristics and applications of radionuclides, medical protection for ionizing radiation and supervision of nuclear and radiation. The score of the questionnaire was used with assignment method.Results The scores were significantly higher after training and education (P< 0.01).Conclusion Training, education and scientific research on radiation protection can effectively improve the ability of KABP to non-radiation staffs in a hospital. Attention should be paid to strengthen the interventions of the management departments.
  • Investigation and analysis of the current situation of clinical nuclear medicine in Shijiazhuang
    JIANG Lihong, LI Peng, SHI Zhenxiang, LI Dongmei, ZHANG Yuanyuan, MENG Yuejie, CHEN Yan
    2018, 27(2): 133-135. https://doi.org/10.13491/j.issn.1004-714x.2018.02.010
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    Objective To investigate and analyze the current situation of clinical nuclear medicine in Shijiazhuang, and provide feasible suggestions.Methods Questionnaire and field surveys were carried out to investigate the status of medical institutions with clinical nuclear medicine departments. The questionnaire included basic information of medical institutions, basic information of the departments, the staff and radiation protection managements; the field investigation included the process layout and the radiation protection facilities.Results There were 6 medical institutions in Shijiazhuang and 12 nuclear medical imaging devices. There were 92 nuclear medicine staff, but they were no nuclear physicists, radiochemists or engineers. The building area of 7 nuclear medicine workplace was small, and 4 of them had some problems in the layout process. The radiation protection management for the medical staff in nuclear medicine department was fairly good.Conclusion To improve the quality and professional knowledge of nuclear medicine practitioners and to optimize the layout process of nuclear medicine clinics are of great significance for promoting the development of nuclear medicine. To strengthen the radiation protection management in the nuclear medicine discipline can make up for the defects of the layout process to a certain extent.
  • An experimental study on the effect of static electricity on radon measurements by using passive methods
    ZHANG Weiyuan, FAN Dunhuang, ZHUO Weihai, JI Huajun
    2018, 27(2): 136-138. https://doi.org/10.13491/j.issn.1004-714x.2018.02.011
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    Objective To qualitatively study the effect of static electricity on radon measurements by using passive integrating radon monitors with solid-state nuclear detectors.Methods An electrostatic induction motor was used to produce different charges and amount of static electricity on the structural material or the CR-39 detectors. Calibration experiments for five groups of radon cups with different charges and amount of static electricity on the structural material or the CR-39 detectors were simultaneously performed in a standard radon chamber, and the results of calibration factors were compared and analyzed.Results Compared with the cup monitors without any electrical charge on the structural material or the CR-39, the calibration factor did not change obviously when the structural material was positively charged, but the calibration factor decreased about 40% when the structural material was negatively charged or the CR-39 detector was positively charged, and the factor would double when the CR-39 was negatively charged.Conclusion In the processes of calibration, storage or use of passive integrating radon monitors with solid-state nuclear detectors, the occurrence of static electricity should be avoided.
  • Analysis on radiation monitoring of security system for metro line 2 in a city
    SHI Mengdie, LIU Huaniu, DENG Zhihong
    2018, 27(2): 139-141. https://doi.org/10.13491/j.issn.1004-714x.2018.02.012
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    Objective To grasp the status of radiological protection for X-ray luggage inspection system used in the Metro Line 2, and to provide technical support and basic data for radiological health management works.Methods A total of 57 sets of X-ray luggage inspection system were investigated. The air kerma rate at a distance of 5 cm from the outer surface was monitored.Results The levels of air kerma rates in the passengers' pathway, staff's working place, the left and right sides of panels, the top cover and the bag claim areas were the same as the background level. The radiation levels inside the system and the entrance or exit of the baggage were higher than the background (P<0.05). The value (6.7 μGy/h) at the entrance of 1 system was found to be higher than the limit of 5 μGy/h, and the averaged value of 0.79 μGy/h surrounding the system was also the maximum among the 57 sets of system. There was a big difference of air kerma rates inside different types or sets of the security inspection systems. The highest value was 5.4 mGy/h, and the mean value was 0.4 mGy/h.Conclusion There exists the X ray leakage at the entrance and exit of the security inspection system when the X-ray is on, but it has little radiation influence on the passengers and staff. However, the management of radiological protection for the security inspection system is still needed to be strengthened. Selection the security inspection system is also worthy of attention.
  • An experimental study on collection and measurement of tritiated water vapor by air condensation method
    DING Hongshen, ZHAO Xinjing, LIU Xiaolin
    2018, 27(2): 142-144. https://doi.org/10.13491/j.issn.1004-714x.2018.02.013
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    Objective To test the performance of air condensation method for collection and measurement of tritiated water vapor in air, to provide technical support for monitoring of tritiated water vapor in the surrounding environment of nuclear power plants.Methods The water vapor in air was condensed to liquid water, and the liquid water sample was distilled and purified, and the activity concentration of tritium in water was measured with a low background of liquid scintillation counter. The precision, accuracy and detection limit of the method are tested, and the applicability of the method were verified.Results The test results of several groups of samples in the laboratory show that, the average relative standard deviation was 14.2%, the relative error ranged from-9.8% to5.2%, and the lower detection limit was 13.7 mBq/m3, which was suitable for the collection and measurement of tritiated water vapor samples in air under humid environment.Conclusion This method can be used to collect and measure the samples of tritiated water vapor in the air around nuclear power plants in wet seasons.
  • Analysis of the intercomparison results on radioactivity measurements by HPGe γ spectrometer system during 2009-2016
    MENG Qinghua, MA Yongzhong, WANG Huan, LOU Yun, BAI Bin, KONG Yuxia
    2018, 27(2): 145-147,152. https://doi.org/10.13491/j.issn.1004-714x.2018.02.014
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    Objective To ensure the accuracy of radionuclide contents in samples measured by HPGe γ spectrometer system, and to improve the expertise of our laboratory technicians.Methods Continuously taking part in the nationwide intercomparison testing on the ability of γ spectrum analysis organized by Chinese Center for Disease Control and Prevention, and thoroughly analyzing the results from 2009 to 2016.Results All of the 25 measured values supplied by our laboratory were qualified. The relative deviation ranged from -17.58% to 13.06%.Conclusion The analysis methods applied for radionuclide measurement are appropriate and the reported results are accurate and reliable in our laboratory.
  • Design of an improved multisphere neutron spectrometer based on boron-doped moderator
    CHEN Ran, CHEN Jun, XU Yongjun, WU Jianhua, LIU Senlin
    2018, 27(2): 148-152. https://doi.org/10.13491/j.issn.1004-714x.2018.02.015
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    Objective A modification of the multisphere neutron spectrometer is proposed in order to improve the energy resolution at low and intermediate energies around some radiation fields, and then to provide information for the calibration of radiation protection instruments.Methods The spectrometer is a set of detector assemblies made of spherical moderators of different sizes, which the polyethylene spheres are surrounded by layers of neutron moderators and absorbers (Boron-containing-PE), each one with a 3He proportional counter placed at the center. By adjusting the thickness and content of the boron shell, the response of the multisphere spectrometer in lower energy has been changed, then a series of response functions with different threshold values are obtained. By this way a set of improved multisphere spectrometer with good resolving power is acquired.Results This design improves the energy resolution of the multisphere neutron spectrometer in the energy range from 1 eV to 10 MeV significantly has been proved by comparing with the conventional multisphere spectrometers.Conclusion The theoretical calculation results indicate that the principle of response functions with different threshold values has greatly improved the energy resolution at low and intermediate energies.
  • Analysis of the intercomparison results of radiation environment monitoring instrument of Shandong Province in 2017
    WANG Guihua, YU Meixiang, WANG Xinxin
    2018, 27(2): 153-155. https://doi.org/10.13491/j.issn.1004-714x.2018.02.016
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    Objective To grasp the situations of equipment and calibration practice of the radiation monitoring agencies in the province by organizing an intercomparison practice, and to improve the monitoring level and ability to ensure the reliability of monitoring data.Methods The quadrant Z-score was used to evaluate the results of ionizing radiation (Gamma dose rate). The results of synthesizing field intensity, electric field and magnetic field of power frequency were evaluated by calculating the relative percentage.Results 50 out of the 51 measurements of ambient gamma dose rate were acceptable, only one was problematic. Except for a result of power frequency magnetic field with a relative deviation of 30.2%, the deviations of other results were all less than 20%.Conclusion The intercomparison practice reflects the current level of radiation environment monitoring in the whole province, the monitoring capability of few agencies needs to be improved.
  • Intercomparison results of soil 90Sr analysis among laboratories
    LOU Hailin, LU Ying, TU Xingming, LI Aiyun, MENG Zhaoju, HOU Shuguo
    2018, 27(2): 156-157,163. https://doi.org/10.13491/j.issn.1004-714x.2018.02.017
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    Objective To test the capability of soil 90Sr analysis, and to improve the measuring level and data accuracy for each laboratory.Methods Organize an intercomparison experiment of soil 90Sr analysis among the nationwide radiation environment monitoring laboratories.Results Twenty laboratories participated in the intercomparison, the results of 80% laboratories are acceptable, while 20% are unacceptable.Conclusion The overall result was fine. Problems found in the intercomparison need future research.
  • Analysis of the radionactivity level in building materials in Chongqing City
    HUANG Qiang, YE Cheng, ZHANG Yan
    2018, 27(2): 158-160. https://doi.org/10.13491/j.issn.1004-714x.2018.02.018
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    Objective To measure the radioactivity level in building materials in Chongqing and to provide scientific data for producing and utilizing the building materials in Chongqing.Methods All of the results on 226Ra, 232Th and 40K contents as well as the internal and external exposure index for 191 building materials collected from 2014 to 2016 in Chongqing are statistically analyzed.Results The qualified rate of samples was 96.4%, the levels of radioactivity in most building materials in Chongqing were below the national standard.Conclusion The radioactivity level of most building materials in Chongqing conforms to the national standard.
  • Radiation environment monitoring and evaluation of an application of 32P in a university
    YU Meixiang, WANG Kun
    2018, 27(2): 161-163. https://doi.org/10.13491/j.issn.1004-714x.2018.02.019
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    Objective To evaluate the radiation impact on surrounding environment from the application of 32P in a university.Methods According to the relevant national standards, the monitoring methods were used, and the limits were taken as evaluation criteria.Results The air kerma rate in the operating room ranged from 62.8 nGy/h to 108 nGy/h, it was within the natural background level of the city. The β surface contamination in the control area was 0.057~0.235 Bq/cm2, it also conformed to the Basic Standards for Ionizing Radiation Protection and Radiation Source Safety (GB 18871-2002). The total alpha and beta activities in the waste water were 0.039 Bq/L and 9.37 Bq/L, also below the their corresponding limits of 1 Bq/L and 10 Bq/L, respectively.Conclusion The application of 32P in the university project is safe for professional staff and the general public with less impact on the environment.
  • A survey of radon exhalation rate from the ground of a rehabilitated uranium mine after 5 years
    LIAO Yanqing, LU Dexiong, XU Mingfa, PENG Chong
    2018, 27(2): 164-167. https://doi.org/10.13491/j.issn.1004-714x.2018.02.020
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    Objective To survey radon exhalation rate from the ground of a rehabilitated uranium mine and assess its potential impact on environment.Methods A total of 150 sampling points evenly distributed on the ground was selected, and the radon exhalation rate at each point was measured by using the radon monitoring system.Results Radon exhalation rates at some sampling points exceeded the national standard. The increased radon exhalation rate could be explained as the geographical changes and decrease of overburden cover.Conclusions Reliable and consistent radiological monitoring is highly recommended, as it is significant in assessing the success of uranium mine sites' decommissioning treatment and rehabilitation.
  • Investigation and evaluation of occupational hazards in the workover operation of an oil production plant
    LI Changsong, LIU Hongqiang, SHAN Yongle, WU Hongtao, ZHANG Fang
    2018, 27(2): 168-172. https://doi.org/10.13491/j.issn.1004-714x.2018.02.021
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    Objective To understand the occupational hazards caused by the workover operation of an oil production plant, and put forward some suggestions for the prevention and control of occupational diseases.Methods According to national standards, the methods of field investigation, detection and combinational analysis in the workplace were used to evaluate the project.Results The main occupational hazard factors in workover job of oil production plant are dust, formaldehyde, acetaldehyde, butyraldehyde, phenol, Benzene, methylbenzene, dimethylbenzene, asbestos fiber and noise. The concentrations of hazardous substances met the requirements of the occupational limits in the workplace. But noise intensity from workover rig exceeded the Occupational allowable limits.Conclusion Formaldehyde, lead dust and noise are the main occupational hazards in Oilfield workover operations, of which noise nuisance is worse. Effective measure,such as innovating technology and strengthening individual protection should be take.
  • The protective efficiency of different materials and the effect on the imaging quality of CT scanning
    WANG Qian, FENG Shichao, LIANG Yuan, MA Xiaohong, ZHAO Xinming, LIU Xia, QI Weiwei
    2018, 27(2): 173-177. https://doi.org/10.13491/j.issn.1004-714x.2018.02.022
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    Objective To evaluate the radiation protection effect of two surface protective materials and the image quality of scanning field in CT field.Methods Bismuth and calcium sulphate for radiation protection materials, The CTDI phantom is used to measure the amount of radiation and CTDIw around the neck during the scan with bismuth and calcium sulphate as radiation protection material or no protection material. Comparison of the shielding effect with or without shielding was performed. 60 patients administrated with low-dose CT screening and were randomly divided into 3 groups:unshielded group, bismuth shielded group and calcium sulfate shielded group, automatic exposure control scanning model was set and tube voltage as 100 kv and reference for 23 mAs tube current. The effect of shielding on image quality was compared with the image quality score of the patients' thyroid and lung.Results The radiation dose of the unshielded group was 6.17±0.21 mGy. It was less than 7.61±0.14 mGy and the center side of the bed side was 7.14±0.11 mGy (P<0.01); The CTDIw of the shielding group was less than that of the unshielded group, and the CTDIw of the bismuth shielding group and the calcium sulfate group was 5.78 mGy, 5.02 mGy, and 6.92 mGy (P<0.05). In clinical studies, the effective dose of 3 groups of low-dose screening was 0.92±0.05 mSv, 0.90 ±0.06 mSv, 0.90±0.05 mSv (P>0.05). Three groups of thyroid and lung tip imaging quality were met the requirements of diagnosis, and shielding set of thyroid imaging quality score was lower than that in group without shielding (F=14.69, P<0.01), which the lowest score of calcium sulphate shielding group; There was no statistically significant difference between the quality scores of the three groups (F=1.57, P>0.05).Conclusion Both bismuth shielding and calcium sulfate shielding can be used as the thyroid surface radiation protection for lung cancer screening without affecting lung tissue diagnosis.
  • Application of low-dose 64 slice spiral CT scanning technology in adenoidal hypertrophy in children
    ZHAO Jianshe, ZHANG Lin, CHEN Yingmin
    2018, 27(2): 178-180. https://doi.org/10.13491/j.issn.1004-714x.2018.02.023
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    Objective To analyze and investigate the application, manifestation and image quality of low-dose 64-slice spiral CT scanning technology on the adenoidal hypertrophy of children, so as to decrease the unnecessary radiation of X-ray and improve the clinic diagnosis.Methods 100 cases of children with suspected adenoidal hypertrophy were divided into two groups randomly, and respectively underwent low-dose (60~80 kV) and conventional-dose (80~120 kV) 64-slice spiral CT scanning. All patients' image quality and diagnostic results of different radiation doses were compared and analyzed.Results 94 children out of 100 were diagnosed with adenoidal hypertrophy, accounting for 94%. The conventional-dose group showed relatively high signal-to-noise ratio, while exposed to more radiation; the low-dose group also got qualified images enough for the clinical diagnosis requirement, but obviously cut down the radiation quantity. There was no significant difference in the diagnosis of adenoidal hypertrophy between the low-dose group and conventional-dose group.Conclusion The low-dose 64 slice spiral CT scanning is able to get accurate evidences for the diagnosis of adenoidal hypertrophy of children, which can provide adequate imaging support for clinical diagnosis.
  • Management requirements and suggestions for production and sales departments of X-ray detection apparatus
    LI Shaoting, LIU Shaohui, ZHANG Zhenbin, ZHANG Gang, XU Zhongyang
    2018, 27(2): 181-184. https://doi.org/10.13491/j.issn.1004-714x.2018.02.024
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    Objective Taking the "source management" as the breakthrough point, eliminating the hidden danger of radiation safety in the production and sales industry of X-ray inspection, ensuring environmental safety and public health, maintaining social stability and promoting the healthy development of industry.Methods Based on the investigation of the distribution, scale, management system, workplace safety, personal protection and recycling of the X-ray apparatus, try to find out the existing problems and put forward appropriate management requirements and effective countermeasures.Results Based on the investigation of the most concentrated enterprises in Dandong, Liaoning Province and Huangshi, Hubei Province, the related regulations on production, sales, maintenance, adjustment, import and transfer were studied.Conclusion Through careful and meticulous analysis of existing management links, some practical solutions, such as improving laws and regulations, strengthening daily supervision and management, establishing department linkage mechanism and so on, are proposed.
  • The clinical and radiographic progression of submandibular sialolithiasis
    FENG Li, WANG Xueting
    2018, 27(2): 185-187. https://doi.org/10.13491/j.issn.1004-714x.2018.02.025
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    Sialolithiasis is a group of diseases which refers to the sialiths of parotid gland, submandibular gland, sublingual gland and minor salivary glands meanwhile bring about Salivary gland inflammation due to the block of salivation. The most common incidence site is submandibular gland. This paper elucidates anatomical features of submandibular gland, formation mechanism,the clinical features and various examination methods as well as results of sialiths. Designed to improve understanding and supply useful iconography information for the formulation of therapy plans.
  • Advances of epidemiologic study on relationship between low-dose radiation exposure and the cardiovascular diseases
    ZHAO Yuqian, SU Yinping, SUN Quanfu
    2018, 27(2): 188-192. https://doi.org/10.13491/j.issn.1004-714x.2018.02.026
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    The risk of cardiovascular diseases (CVD) caused by low dose ionizing radiation has attracted more and more attention, but there is lack of consistency among the existing epidemiologic data. In this paper, cohort studies of A-bomb survivors, occupation exposure and radiotherapy accepted patients with breast cancer are summarized to reveal the relationship between low dose ionizing radiation and CVD in recent 10 years.