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  • 28 February 2018 Volume 27 Issue 1
      
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  • Radiation effects of spent fuel transport under different transport modes
    MA Wenjuan, HONG Zhe, PAN Yuting
    2018, 27(1): 1-4. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.001
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    Objective To study the radiation effects of spent fuel transportation from Guangdong to northwest region under different modes.Methods Using the CRAMTRA 1.0 code, radiation doses of spent fuel transportation under different modes on the typical public and workers were calculated.Results The public collective effective dose per ton of spent fuel delivered to the public had the greatest impact on long-distance road transport (1.65×10-3 Sv/t), while the Road-Ocean-Rail transport mode had the least radiation impact (2.63×10-4 man·Sv/t), and the radiation impact of Road-Rail transport mode was the middle (4.51×10-4 man·Sv/t). The long-distance road transport mode had a significantly higher occupational exposure to workers (6.00×10-1 man·Sv/t) than that of Road-Rail transport mode (7.93×10-2 man·Sv/t) or Road-Ocean-Rail transport mode (1.05×10-1 man·Sv/t).Conclusion The radiation effects of Road-Ocean-Rail transport mode is relatively small.
  • Investigation and analysis of individual dose levels of external radiation in interventional and nuclear medicine radiation workers
    CHEN Yan, ZHANG Yuanyuan, ZHANG Weijia, ZHOU Jing, SHI Zhenxiang, LIU Yong
    2018, 27(1): 5-8. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.002
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    Objective To grasp the level of external radiation exposure to interventional and nuclear medicine staff, and to evaluate the protective effect of the radiation workers in order to provide a scientific basis for radiological protection and management.Methods Thermoluminescence dose meter was applied to monitor the occupational exposure to individuals according to GBZ 128-2002 "Specifications of Individual Monitoring for Occupational External Exposure" and GBZ 207-2008 "System Performance Testing Specification for Individual External Dose".Results The external exposure of 324 radiation workers including 287 in interventional radiology and 37 in nuclear medicine were monitored in 2015. The medians of their annual doses monitored under aprons were 0.9、1.14 and 0.86 mSv, and the ones monitored over aprons were 1.96、5.86 and 1.37 mSv in Grade ⅢA, Grade Ⅲ and Grade ⅡA hospitals, respectively. Significant differences (P<0.05) were found among the different grades and classes of hospitals.Conclusion The annual effective dose of 324 radiation workers was all under the standard limit value (20 mSv/a). Significant differences of individual exposure observed in different grades of hospital and types of work suggests that effective protection measures should be taken to reduce the radiation exposure, and the individual monitoring should be strengthened.
  • Survey and analysis of radioactivity levels in environmental samples and food in Xuzhou City between 2015 and 2016
    LIU Nian, XUE Cheng, MIAO Shenghao, WANG Yueran
    2018, 27(1): 9-12. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.003
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    Objective To understand the levels of gross α and gross β in environmental samples and food in Xuzhou City.Methods According to requirements of food safety risk monitoring program of Jiangsu Province, the low background α/β counter (BH1216Ⅲ) was applied to measure the gross α and gross β in atmospheric fallout, drinking water, aerosols and food in Xuzhou.Results Both the levels of gross α and gross β in drinking water decreased over the past 10 years, and the levels of gross α and gross β in food are not significantly different from those in surrounding cities.Conclusion For accumulating more basic data, both the scale and items of this survey should be further enlarged in Xuzhou.
  • Analysis of radiation level and exposure dose of personnel in the diagnosis and treatment workplace of nuclear medicine in Guangdong Province
    ZHANG Zaoqin, GENG Jiwu, LIN Lan, YANG Yuhua, XU Zhiqiang, XIA Bing
    2018, 27(1): 13-17. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.004
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    Objective To understand the status of radiation protection at workplace and the level of individual dose in some clinical nuclear medicine departments in Guangdong Province, so as to provide data support for finding the key points to control their occupational hazards.Methods Taking 14 Grade ⅢA hospitals in Guangdong Province as the study objects, the ambient dose equivalent rate, the level of radioactive contamination and the individual dose (Hp(10)) were monitored or estimated according to the relevant national standards.Results A highest ambient dose equivalent rate of 166 μSv/h was found around the operating holes of 18F synthesis chamber. The dose rates to hands were generally higher during the procedures of packaging and injecting radionuclides. In the packaging procedure, the highest dose rates were 3720 μSv/h, 1220 μSv/h and 468.2 μSv/h for packaging 18F, 131I and 99Tcm, respectively; and there were 537 μSv/h and 882 μSv/h for injecting 18F and 99Tcm. In the 18F injection room of one hospital, the beta surface contamination were as high as 99.6 Bq/cm2 and 1.6 Bq/cm2 on the working table and a staff hands, both of them exceeded the national standards. The annual effective dose of nuclear medicine staff ranged from 0.08 mSv to 5.18 mSv. Without protective measures, the annual equivalent dose of hands ranged from 0.02 mSv to 390 mSv and from 0.57 to 85.62 mSv for repacking and injection staff, respectively. However, the exposure to their lens, whole body and abdomens were relatively low.Conclusion Workplace protection in nuclear medicine departments is fairly well, however, the self-protection should be further reminded. Skillful operation can shorten the exposure time, and other reasonable protective measures will reduce the radiation dose.
  • The effect of KS and CP on hematopoiesis regulation in irradiated mice
    KONG Shaofan, YANG Fujun, MENG Yuanyuan, YANG Xiangdong, LIU Yaoyao, SONG Naling, XU Wenqing
    2018, 27(1): 18-20,24. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.005
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    Objective Investigate the effect of KS and CP on hematopoietic reconstitution in irradiated mice.Methods C57BL/6 mice were divided into four groups randomly, such as blank control group, irradiation control group, irradiation with KS group and irradiation with CP group. The last three groups were underwent irradiation of 5.5 Gy 137Cs-γ rays,and the dose rate was 1 Gy/min. After irradiation treatment, mice in KS groups were given KS orally (1.5g/kg) twice every three days, mice in CP groups were given CP orally (2.7 g/kg) twice every three days, and mice in two control groups were given normal saline orally twice every three days. Peripheral blood was checked every month after irradiation. Another group of mice were divided into 4 groups identically, given KS, CP or normal saline everyday after treated with 5.5 Gy 137Cs-γ rays. CFU-F was tested one month after radiation.Results The number of white blood cell and lymphocyte in KS group and CP group was higher than irradiation control group.Conclusion KS and CP can promote hematopoietic recovery in irradiated mice.
  • Effect of tea polyphenols on chromosomal aberration of CHL cells and micronucleus formation induced by radiation
    LI Qihui, WANG Fang, WANG Xiude, ZHANG Huibin, GU Qiamin, SHANGGUAN Tao, ZOU Zhongmin, TANG Mutao
    2018, 27(1): 21-24. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.006
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    Objective To study the effect of tea polyphenols(TP) on chromosomal aberration of Chinese hamster fibroblast cells(CHL) and micronucleus formation induced by radiation.Methods CHL cells (with and without S9)were divided into control group, positive control group, radiation group and TP protective group which were given TP12.5、25、50 μg/ml. Both cells were exposed to 2 Gy 60Co γ rays except control group and positive control group. After cultured in 1640 for 24 hours, cells were harvested for the preparation of chromosome. Subsequently, the ratio and the type of chromosomal aberration were examined. 50 mice were divided into control group, 60Co γ ray radiation group and TP protective group which were given a gavage of TP 725, 145, 29 mg/kg. 10 mice each group. After 14 days the mice were received 6 Gy 60Co γ radiation and were executed after radiation exposure 24 h. By means of bone marrow smear and Giemsa staining, the number of micronucleus cells per 1 000 polychromatic erythrocyte (PCE) was counted.Results The ratios of chromosomal aberration of TP protective group(25、50 μg/ml) were significantly decreased compared with radiation group. S9 has no effect on the type and rate of chromosomal aberration. Compared with radiation group, the micronucleus ratio of TP protective group (725 mg/kg and 145 mg/kg) were significantly decreased(P<0.05).Conclusion TP could partly resist chromosomal aberration of CHL cells and micronucleus formation induced by radiation. TP has protective effects on damage of chromosome.
  • Effect of low-dose X ray on human umbilical vein endothelial cells (HUVECs) secreting von Willebrand factor (vWF)
    WANG Yifan, ZHENG Yingying, XIE Qi, LIU Ju
    2018, 27(1): 25-27. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.007
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    Objective To determine the effects of low-dose (0.1 Gy) X-ray on secretion of von Willebrand factor (vWF) in human umbilical vein endothelial cells (HUVECs).Methods HUVECs were irradiated at the doses of 0 Gy (control) and 0.1 Gy (200 cGy/min) by a medical linear accelerator. The proliferation, viability and apoptosis of the irradiated HUVECs were examined through MTT assay, Trypan Blue exclusion and flow cytometry. The secretion of vWF was detected through ELISA and Western blot of the culture media of the irradiated HUVECs.Results There were no statistically significant differences between the control group and the experimental group in proliferation, viability and apoptosis of HUVECs. However, the secretion of vWF in the experimental group was increased significantly.Conclusion Low-dose (0.1 Gy) X-ray irradiation does not change the proliferation, viability and apoptosis of HUVECs, but increases the secretion of vWF from HUVECs.
  • Analysis on thyroid function of medical radiation workers in a city
    SHI Ruifen, DONG Xuemei, CHEN Songgen, CHEN Zhiling, WU Jiancong
    2018, 27(1): 28-30. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.008
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    Objective Analysis of serum thyroid hormones in medical radiation workers in a city and the effects of long-term low-dose ionizing radiation on their thyroid function.Methods Through epidemiological survey methods, we analysed the thyroid function in 1615 medical radiologists by detecting serum T3, T4 and TSH content in accordance with the requirements of occupational health examination of radiation workers and conducted statistical analysis for the measurement combined with personal dose monitoring data.Results The annual average effective dose of radiation group was 0.23 mSv, which belonged to low dose contact ionizing radiation. The level of T3, T4 and TSH in treated group were all higher than those in the control group (P<0.05). According to the length of service, people were divided into three group and the levels of T3, T4, and TSH were not statistically significant among each group (P>0.05); Group by different types of work, except the TSH level of dental radiation group, the remaining groups were statistically significant compared with the control group (P<0.05).Conclusion Long term exposure to small doses of ionizing radiation may affect the thyroid function of radiation workers. Therefore, we should further improve the radiation protection conditions, strengthen the awareness of the radiation workers and ensure the occupational health of the workers.
  • Investigation and analysis of frequency of X ray diagnostic exposure in Mianzhu in 2016
    MENG Qingchun, LONG Yiqian, LI Tao
    2018, 27(1): 31-33,51. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.009
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    Objective Collecting information about the distribution and frequency of usage of X-ray diagnostic equipment in the city to provide suggestions for the standardization of medical radiation management and radiation protection.Methods Statistical analysis of data about the frequency of radiological diagnosis and treatment in all hospitals in the city.Results The number of physicians of the city is 5.07/1000 in 2016; frequency of radiological diagnosis and treatment is 510.67/1000, of which male is 543.89/1000and female is 477.63/1000. The percentage of photography、X-CT、chest X-ray radiograph、dental、mammary gland CR、interventional operation and gastrointestinal fluoroscopy are 74.89%、17.46%、4.40%、2.15%、0.48%, 0.36% and 0.26% respectively; differences of distribution of photography and X-CT on each part between genders, as well as among ages, were statistically significant. In 2016, the number of radiological diagnosis and treatment in Level Three hospitals is 84289 (32.68%), Level Two hospitals is 85574 (33.18%), and the remaining is 88061 (34.14%).Conclusion The annual frequency of radiological diagnosis and treatment in this city belongs to level Ⅱ health care level. This frequency is higher than average level of the world, and is also higher than what had been reported in China in recent years. However, the frequency distribution of different radiological diagnosis and treatment appears not rational.
  • Investigation and analysis of medical irradiation level in Xuzhou City from 2013 to 2015
    WU Pangpang, YANG Jing, LOU Donghua, WU Gang, LU Xingzhan, XU Shuhai
    2018, 27(1): 34-38. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.010
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    Objective To understand and master the status of radiation diagnosis and treatment as well as their development in Xuzhou City, to provide data basis for the rational allocation and supervision of radiation diagnosis and treatment, and to promot the rational development of radiation diagnosis and treatment.Methods Taking all radiation diagnosis and treatment institutions in Xuzhou as the survey object, using the letter and visit investigation method to carry out the survey.Results A total of 314 institutions were surveyed in Xuzhou City, both the number of device and radiation workers increased in 2013-2015, but the number of radiation workers for each piece of device did not obviously changed, and the regional distribution of device was uneven. The total frequency of medical uses of radiation was in the upward trend, with the fastest growth in nuclear medicine treatment. The frequency of X-ray diagnosis was highest in the Grade I and other hospitals, while radiotherapy, interventional radiology and clinical nuclear medicine were mainly concentrated in the Grade Ⅲ hospital.Conclusion The medical radiation resources increased year by year, but their regional distribution was uneven. The total frequency of medical uses of radiation also increased year by year, but the overall level was still much lower than the economically developed regions such as southern Jiangsu. Controlling the medical exposure to radiation workers and public and enhancing their protection have become the main tasks of radiological health supervision.
  • Study on the effective dose of CT in PET/CT on automatic tube current modulation
    WU Yitian, GENG Jianhua, DU Zhaomeng, BI Gaochang, QI Yonghe, ZHANG Chaokun, ZHENG Rong, WU Ning
    2018, 27(1): 39-43. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.011
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    Objective To investigate the relationship between effective dose and tube current threshold, as well as noise index of CT in PET/CT, and to provide theoretical basis for optimal acquisitions through the mode of automatic tube current modulation (ATCM).Methods Two sets of PET/CT (Discovery ST-16 and Discovery Elite) and an anthropomorphic phantom (RS-550) were used to acquire the effective dose caused by CT in PET/CT.CT acquisition conditions were as follows in both ST-16 and Elite PET/CT:tube voltage 120 kVp, pitch 1.375,rotation speed 0.8 s,noise index ranged from 8 to 30 with an interval of 2,the low limit of current was 30mA,and the high limit ranged from 200 mAto 350 mA with an interval of 50 mA. Simulating the clinical head-neck and body conditions, the phantom was scanned, and the dose-length product(DLP) was recorded to estimate the effective dose (EDCT) of CT.Results With the same acquisition conditions, the effective dose decreased along with the increasing noise index, and the curve became steeper with increasing high limit of tube current. The whole body effective dose caused by CT was lower in Elite PET/CT than that in ST-16 with the same acquisition conditions.Conclusion The effective dose caused by CT in PET/CT differs from variable scan conditions. It shows that the radiation dose can be effectively reduced by choosing appropriate acquisition conditions according to different clinical needs.
  • Study on the dose burden of the residents in Shenzhen from the X-ray computed tomography medical exposure
    WANG Haijun, CAI Jinmin, LUO Jingan, LIN Yongqin
    2018, 27(1): 44-47. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.012
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    Objective To understand the current situation of CT medical exposure in Shenzhen, and to estimate the resident's dose burden.Methods Using census method to investigate CT scans in medical institutions in Shenzhen in 2016. Firstly, the general scanning parameters and the annual scanning numbers of CT application in hospitals in Shenzhen were investigated for head, thorax, abdomen and other sites examinations, respectively. Based on the measured weighted CT dose index (CTDIw) and published literatures, the dose burden of residents in Shenzhen from CT scans was estimated.Results The frequency of CT application in Shenzhen in 2016 was 109.84 person per thousand population. The effective doses from head, thorax and abdomen CT scanning were 1.21 mSv, 5.83 mSv and 7.08 mSv, respectively. The collective effective dose of the residents in Shenzhen in 2016 from CT scans was 6090.28 Sv·person, and the averaged annual effective dose was 0.530 mSv.Conclusion The frequency of CT application and single-scan dose are two important factors affecting the dose burden of residents, it's an effective way to reduce the resident's dose burden by reducing all unnecessary exposure and establishing the dose reference levels for CT scans.
  • Comparative study on the entrance surface dose of oral COPT and CBCT subjects
    TIAN Qingxiang, LOU Yun, WANG Hongfang, WANG Xinming
    2018, 27(1): 48-51. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.013
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    Objective For comparison of the entrance surface doses in the two types of computed orthopantomography(COPT) and cone beam CT(CBCT).Methods The thermoluminescence dosimeter (TLD) was used to measure the entrance surface doses (ESD) undergoing oral scans with COPT and CBCT in two types of oral CT. In the experiments, the TLD elements were placed at 12 focused points of the head phantom, and their doses were measured by the RGD-3B® reading system.Results For the two types of CT under COPT routinely using conditions, the ESDs of CBCT were all higher than those of COPT, and the ratios ranged from 1.2 to 9.8 and 1.8 to 14.4 for type A and type B device, respectively.Conclusion Dentists should realize different doses from the two inspection methods of COPT and CBCT, and select appropriate exposure conditions, guide the examinees to use the personal protective equipment correctly, in order to reduce radiation hazard to the lowest possible level.
  • Verification for the representative sampling system of “Hualong I” NPP gaseous effluent: test and analysis
    LI Hang, LI Hang, DING Shi-hai, WANG Yong, DU Wenxue
    2018, 27(1): 52-57. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.014
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    Objective Through experimental verification to ensure the sampling system (a single nozzle sampling head design) for the chimney gaseous effluent designed for the third-generation pressurized water reactor nuclear power plant "Hualong I" independently developed in China fully meets the sampling representative requirements.Methods Based on the requirements of American National Standard ANSI/HPS N13.1-1999, a 1:5 scale model of the "Hualong I" reactor stack was built to test the average cyclonic angle, gas flow velocity distribution, tracer gas distribution and tracer aerosol distribution in three different sampling cross sections. The verifications of the cyclonic angle, gas flow rate, and tracer gas concentration distribution were conducted in the Fuqing Nuclear Power Plant No. 1 and No. 2.Results In the central 2/3 area of the three pre-selected sampling sections (Q1, Q2, Q3) in the "Hualong I" proportional model stack and under two designed ventilation conditions, the coefficient of variations (COVs) of the gas flow velocity distributions were ≤ 1.1%, the maximum cyclone angle of all the measured point was 11.38°, the COVs of the tracer gas concentrations distribution were ≤ 4.4%, the COVs of the tracer aerosol concentrations distributions were ≤ 4.7%. As well as in the central 2/3 area of the real stack pre-selected sampling section, COVs of the gas flow velocity distributions were ≤ 8.4%, the mean absolute value of cyclone angles at all points was 11.3° (the maximum value was <20°). When the tracer gas injected from DVN iodine exhaust and the DVN normal exhaust, the distribution COVs of the tracer gas concentrations on the measured section were 2.2% and 1.3% respectively.Conclusion All test indicators of the "Hualong I" model stack and the real stack agree well with the requirements of ANSI/HPS N13.1-1999 standard for mixing uniformity of pollutants on the sampling section, the single point sampling method can be used to design the "Hualong I" stack gas flow sampling system.
  • Characterization survey for waste water tanks and surrounding areas of heavy water research reactor
    NIE Peng
    2018, 27(1): 58-61. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.015
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    Objective To judge the running states of the waste water tanks of a heavy water research reactor (namely 101 reactor).Methods The groundwater, soil and transit pumping rooms around the waste water tanks were investigated through on-site measurement or laboratory analysis to identify areas with high soil contamination or high radiation dose levels.Results Results of the soil and groundwater around the waste water tank showed that the waste water tank had no adverse impact on the surrounding soil and groundwater during the past operations; the results of transit pumping rooms indicated that the soil under the room area and the ground inside the rooms had been contaminated in different degrees.Conclusion In general, the waste water tanks of the heavy water research reactor are in good condition.
  • Measurement and analysis about the relationship between the dose of OSL and the counting of fluorescence
    WANG Jianchao, ZHOU Jianliang, CHEN Ling, WU Jianhua, LIU Yang, ZHOU Shuli
    2018, 27(1): 62-64. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.016
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    Objective Based on the principle of OSL, measure and analyze the relationship between the dose deposited in the element and the number of excited fluorescent photons in order to provide a reliable basis for future researchinstrument.Methods Use a 1.48 GBq (40 mCi) of 90Sr/90Y β source to irradiate the element of α-Al2O3:C at different times, then use the designed laser to stimulate the signals in the α-Al2O3:C, fluorescent photons are collected through a photomultiplier tube and finally counted by a single-photon counter.Results The relationship between the dose deposited in the element and the number of fluorescent photons is obtained by the experimental method above, and the results can be fitted in linear equation.Conclusion There is a linear relationship between the background dose on the element and the number of fluorescent photons, at the same time the dose deposited in the element and the number of fluorescence photons also shows a linear relationship.
  • Development of emergency radiation monitoring system for special conditions
    LIU Yang, GUO Luzhen, ZHENG Guowen, LUO Zhiping, CHEN Qin
    2018, 27(1): 65-68,73. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.017
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    Objective An Emergency Radiation Monitoring System was developed for special environment conditions. It is helpful for emergency actions.Methods Using UVA carries and throws radiation detectors to the accident area, the detectors transmit radiation and position data to computer by wireless data transmission module. Based on the structure and aerodynamic design, the detector has the ability of resistance of high temperature, high humidity and strong impact.Results After thrown from 30~100 m height, the detector can continually work more than one month. The detector get the protection grade of IP68 and can work well at the temperature of -20℃~85℃.Conclusion It can fulfill the needs of emergency radiation monitoring after severe nuclear accident.
  • Comparison and analysis of environmental γ-radiation levels by using different monitoring methods
    GONG Zengyan, ZHAO Guangcui, LI Xuezhen, GAO Peng, MA Guoxue, XU Meng
    2018, 27(1): 69-73. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.018
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    Objective To discuss the results of terrestrial γ radiation using different monitoring methods.Methods Five environmental monitoring points and two supervisory monitoring points were selected, and results of γ dose rates from the automatic continuous monitoring (ACM),instantaneous monitoring (IM) and cumulative monitoring (CM) during 2010-2014 were compared.Results The results at same point showed that γ dose rates monitored by the ACM were the largest, those of the CM were the second, and those of the IM were the smallest. For the same point in the five years, the standard deviations were 0.62~6.96 nSv/h and 4.95~28.11 nSv/h by using the same and different monitoring methods, respectively.Conclusion To a certain extent it has been proved that the terrestrial γ radiation monitored by the three methods is scientific and comparable. It is able to guarantee the quality of monitoring data, and it is of great significance to optimize monitoring points in the radiation environment.
  • Tritium level around HFETR in Sichuan Province
    ZHANG Li, MAO Wanchong, LI Bin
    2018, 27(1): 74-76,88. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.019
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    Objective To investigate tritium concentration in the external environment of a high flux engineering test reactor (HFETR) in Sichuan.Methods The river water, shallow water, air and precipitation samples were collected around the test reactor in a 5 kilometers radius from 2010 to 2014, tritium in the samples was analyzed by an ultra low level liquid scintillation spectrometer according to the GB12375-90《Analytical method of tritium in water》.Results Tritium concentrations in air and precipitation within 1 km of the test reactor are relatively high and the concentration decreases with the increase of the distance between monitoring spot and the test reactor. The concentrations in water and shallow water are at normal levels, indicating that the tritium impact on surrounding areas is very small.Conclusion The annual effective dose intake by the adult is the highest and of 2.1×10-8 Sv, it is only about 2 ‰ of the dose limit set for public.
  • Analysis of the specificity of 64-slice spiral CT scan in early diagnosis of hepatocelluar carcinoma and focal nodular hyperplasia
    SHEN Mingxiong
    2018, 27(1): 77-80. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.020
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    Objective To investigate the application of 64-slice spiral CT in the early diagnosis of primary hepatocellular carcinoma (HCC) and focal nodular hyperplasia (FNH) and sensitivity and specificity analysis.Methods From January 2016 to January 2017, 56 patients with highly suspected HCC and 45 patients with highly suspected FNH were selected as research objects. All patients underwent 64-slice spiral CT scan and enhanced scan, and the sensitivity and specificity of spiral CT in the early diagnosis of HCC and FNH were compared with postoperative pathological findings, and compared the contrast-to-noise ratio(CNR) and energy dispersive spectrum(EDS) quantitative parameter values under different energy levels both in CT enhancement scan.Results The sensitivity of 64-slice spiral CT in the early diagnosis of HCC was 96.23%, the specificity was 66.67%, and the accuracy was 92.86%; and the sensitivity of the early diagnosis of FNH was 92.68%, the specificity was 75.00%, and the accuracy was 86.67%. In the enhanced arterial phase, the CNR of HCC and FNH patients showed a significant decline, and the higher the energy, the lower CNR, and there were a significant difference in CNR between HCC and FNH patients(P<0.05); the CNR of FNH patients in the portal phase gradually decreased, and obtained the best CNR at 40 keV. HCC patients showed a rise first and then a decrease in CNR, and the best CNR was obtained at 80 keV. There was a significant difference in CNR between patients with FNH and patients with HCC at 80-120 keV(P<0.05), but no significant difference at 40 keV (P>0.05).Conclusion 64-slice spiral CT in early diagnosis and differential diagnosis of HCC and FNHhas important clinical value, and detection efficiency, sensitivity, specificity are high.It has clinical application and promotion value.
  • Application of cross-modality fusion images of 18F-FDG SPECT and GE 64 row CT in diagnosis of colorectal neoplasms
    ZHANG Yongqiang, WANG Yunlu, LIANG Yan, LI Zhanzhan, ZHAO Jie, HE Zilong, CHEN Weiguo
    2018, 27(1): 81-84. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.021
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    Objective To explore the advantages of cross-modality fusion images of 18F-fluorodeoxyglucose single photon emission computed tomography(18F-FDG SPECT/CT)and GE 64 row CT in diagnosis and TNM staging of colorectal neoplasms by comparing the images quality before and after fusion of both machines.Methods Thirty-six patients of colorectal neoplasms confirmed by pathology were examined by 18F-FDG SPECT/CT and hetero machine 64 row CT. The images were transferred to the post processing workstation, and 18F-FDG SPECT images were completed and fused with low energy CT and heterogeneous 64 row CT images by the same machine. 65 lesions from 36 patients, including 36 primary,19 metastatic lymph node and 10 distant metastasis were divided into 3 groups. The images processed by co-modality fusion and cross-modality fusion were scored respectively on clarity of mass boundary, clarity with adjacent organs and image artifacts. Wilcoxon test was used to compare the quality score of co-modality fusion with those of cross-modality fusion images.Results Score of cross-modality fusion images was higher than those of co-modality fusion images, which was statistically significant(z=-5.303 and -3.858 and -2.844,P<0.01).Conclusion Cross-modality fusion images of colorectal primary tumors, lymph nodes and distant metastasis are better than co-modality fusion images. Cross-modality fusion is worthy to be popularized in clinical practice.
  • Study on the management of radiation safety about airport cargo radioactive warehousing
    WANG Yue, CHEN Dongbing, ZHANG Jingchen, JU Zhihao, DU Binggui, SONG Zhiyan
    2018, 27(1): 85-88. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.022
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    Objective To study the supervision mechanism of the environmental protection department about the airport cargo radioactive warehousing and ensure its radiation safety.Methods Through investigating the current status of airport radiation safety management at home and abroad, and combined with actual situations, suggestions are made to improve the management of radiation safety on airport radioactive warehousing in our country.Results It is clear that the safety management of airport radioactive warehousing belongs to the category of transportation management, current deficiencies in management of airport radioactive warehousing need improvement.Conclusion To standardize the management and explicit responsibilities of airport radioactive warehouse safety can ensure the airport radiation safety to the maximum extent.
  • Investigation and analysis of present radiological protection work in military medical institutes in Beijing
    LI Dongyu, ZHANG Lei, LU Wei, WANG Xinggong
    2018, 27(1): 89-91. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.023
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    Objective To investigate and analyze the radiological protection work carried out in military medical institutions in Beijing.Methods By means of survey and field measurement.Results In recent years, radiological protection has been continuously strengthened in military medical institutions, however, insufficient testing capability, unreasonable protection design and imperfect regulations and standards are still needed to be improved.Conclusion To strengthen the radiation protection work of military medical institutions, it is necessary to further improve the level of testing capability for the technical service institutions, improve the organization of radiation protection management in medical institutions, improve the rules and regulations, strengthen the study on the regulations and standards of radiation protection, and establish a solid technical support system.
  • Methods for protecting CT non-scanning areas
    CHEN Jiwei, LU Chenhao, TANG Bo, PENG Guanliang, CAO Juntao, TU Yu, HUANG Shengyan
    2018, 27(1): 92-96. https://doi.org/10.13491/j.cnki.issn.1004-714x.2018.01.024
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    Objective To analyze and study the protective methods for sensitive tissue or organs in non-scanning areas.Methods By analyzing the causes of radiation in the non-scanning area, the protection schemes are put forward.Results Radiological health management should enhance personnel protection awareness, regulate the internal and external environment of machine room, and perfect the rules and regulations. The operator should use advanced technology to carry out the scanning, there are three methods, i.e. body surface shield, the source block and the body shield. The body surface should select advanced shielding material and choose personal protective equipment larger than 0.5 mm lead equivalent. The method of source block shielding is to block both sides of the CT frame aperture, which will greatly reduce the leakage and scattered rays in the non-scanning area. In vivo, increasing the local density of the digestive tract is used to attenuate the inner scattered rays of the body through oral administration of barium sulfate. The practicability and feasibility of source block and body shielding should be further verified by experiments.Conclusion The protection of sensitive tissues and organs during CT examination should be guided by the principle of "emphasizing operation and protection technology, strengthening radiological health management". In CT operation, under the condition of meet the image quality, choose low-dose scanning mode. As the protection technology, it should be in accordance with the concept protection of "shield leakage radiation, attenuate scattering radiation".