The Exploration Of Radiation Protection Awareness And Intervention Methods Of CT Radiographers In Some Hospitals And The Investigation Of Children's CT Dose

The exploration of radiation protection awareness and intervention methods of CT radiographers in some hospitals and the investigation of children's CT doseBackgroundSince the invention of CT in 1971,with the development of science and technology,the application of CT has become more and more popular due to its advantages of high density resolution,non-inventiveness and rapacity,and the examination frequency of children's CT and its contribution to the collective effective dose have also increased rapidly.Among the common X-ray imaging examinations,the single dose of CT scan is the largest,especially for children,who are more sensitive to radiation and take the risk of longer life expectancy.Since the 1990s,cancer risk estimates and epidemiological investigations have found that CT scans in children can lead to a significant increase in the risk of leukemia and brain tumors.Therefore,it is very important to strengthen the radiation protection in children's CT scans and reduce the radiation dose.In the process of CT scan,radiation parameters are one of the most important factors to determine the dose of exposure,and the cognitive level of technicians plays an important role.The results of the investigation on the radiation protection of medical workers abroad show that the cognition level of the respondents in the radiation dose,risk and parameter setting of the radiological diagnostic procedure needs to be improved.Domestic investigation of CT technicians is less.By investigating the radiation cognition level of CT technicians and the CT dose of children,this study provides a scientific basis for exploring the methods to improve the radiation protection cognition level of radiographers and comprehensively carrying out the dose optimization of children CT examination in the futureObjective1.To understand the current status of CT radiographers' cognition of radiation dose and risk parameter setting and diagnostic reference level(DRL)in children with CT scanning.2.To investigate the parameters setting and radiation dose of CT scan of children's head and chest,and put forward optimization suggestions for relevant medical institutions,so as to provide the theoretical basis for the next step of dose optimization.3.Conduct education and training for CT radiographers,and evaluate the training effect,to explore methods to improve the awareness of radiation protection of radiographers.Methods1.According to the level of economic development and geographical location,1-2 regions were selected in the eastern,central and western regions,3-5 medical institutions were selected in each region(each region must include specialized hospitals such as children's or maternal and child health centers),and 25 medical institutions were finally selected as the survey sample.2.Using the method of quota sampling and selecting a self-designed questionnaire as a tool,the authors studied radiologists in 25 medical institutions who operated CT scanners on a daily basis to investigate their awareness of children's CT scan radiation dose and risk,parameters affecting image quality and radiation dose,CTDIvol and diagnostic reference level(DRL).3.The parameter setting of children's CT scan and the radiation dose survey adopted the quota sampling method.In the medical institutions,2/3 samples were selected according to different types and levels of the hospital.Choose a CT scanner in each medical institutions,to collect the head and chest scanning data in each age group(0-<1,1-<5,5-<10 and 10-15),10 cases used to submit DICOM file or field records,extract or records scanning parameters and radiation dose,using CT-Expo v2.3 software to calculate effective dose and organ dose.To understand the CT scan parameters and radiation dose(CTDIvol and DLP)in different hospitals,select the medical institutions that need to be optimized.4.Experts were invited to conduct thematic training for the respondents and questionnaire survey was used to evaluate the effect of the intervention methods.5.Each objective question in the questionnaire survey answer for 1 score,a right answer is incomplete or incorrect is 0.CTDIvol and DLP were used as indexes for dose investigation.Epidata 3.1 was used for data entry,and Stata/SE 11.1 was used for data collation and analysis.M(iqr)was used to represent the quantitative data,the rate and ratio of the qualitative data was described,the rank sum test was used for the difference analysis among different groups,and the Logistic regression analysis was used for the analysis of influencing factors.Results1.In this study,148 CT radiographers from 25 hospitals in 5 regions including Q,N,E,X and J participated in the questionnaire survey.11.5%of the respondents were able to compare the radiation dose of different scanning schemes,15.5%understood the meaning of DRL,but only 9.5%had the correct application ability.In terms of the radiation dose and risk perception of CT scanning,only 21.6%of the respondents believed that CT scanning would increase the risk of childhood cancer.In different types of medical institutions,the cognitive of specialized hospitals in natural background radiation dose and whether abdominal ultrasound involved ionizing radiation was higher than that of other types of medical institutions(?2=13.8,10.0,P<0.05);In different regions,E region had higher awareness in the random effects of CT scan,radiation dose of different radiological diagnostic procedures,and radiation dose of head CT(?2=11.1,18.8,11.9,P<0.05).In terms of setting CT scanning parameters,72.9%of the respondents believed that tube voltage and tube current were the common factors affecting image quality and radiation dose,but they had little understanding of such parameters as thickness and scanning time.The cognition of ATCM in E was significantly higher.The awareness of radiographers in different regions was significantly different(F=6.854,P<0.05),the cognitive level of E region was higher.2.In this study,CT scan files of 995 children were collected from 14 CT scanners in 14 hospitals.CT scan of children's head and chest with CTDIw or CTDIvol,DLP,effective dose and organ dose were higher or close to previous investigations,suggesting that some medical institutions need to carry out parameter optimization actions.In children's head CT,CTDIvol of NHF,NB and HZH were 130.6%,76.4%and 60.6%higher than the average level of medical institutions,respectively.In chest scan,CTDIvol of NHF and NB were 1.07 and 2.17 times higher than the average level of medical institutions,respectively.In addition,65.0 percent of chest scans used automatic tube current modulation,with CTDIvol and DLP 1.4 times lower than those not used.3.A total of 32 respondents from Q and N regions received training.Compared with pre-intervention cognitive status,the objects in children CT radiation risk(21.6%vs 81.2%),stochastic effects CT scans(4.1%vs.18.7%),the different typical radiation dose of radiation diagnostic procedures(66.2%vs.87.5%)and radiation dose of head CT(21.6%vs.37.5%),and other issues of cognitive status improved remarkably,the understanding and application of diagnostic reference level is improved remarkably,too.However,the cognitive improvement of parameters that affect the image quality and radiation dose of CT scan is not obviousConclusion1.The cognitive level of CT radiographers on children's CT scan radiation risk,parameters affecting image quality and radiation dose,and CTDIvol need to be improved.The cognitive level of radiographers in different regions is significantly different.The targeted thematic lecture training has improved the cognitive of radiation protection of radiographers,but the cognitive improvement effect on the parameters affecting image quality and radiation dose are not obvious,which may be related to the more practical operability in this aspect.2.There are differences in dose levels among different medical institutions.Compared with the overall average level,the CTDIvol of head and chest CT scan in medical institutions with higher dose can achieve 2.3 and 3.2 times,respectively,suggesting that we can appropriately reduce the scanning parameters without affecting the image quality.The use rate of ATCM in chest CT scan in this survey is only 65.0%,which may be related to the lack of correct understanding of it by radiographers and the abandonment of its use,so the training of radiographers should be strengthened.