A survey of CT doses in Saudi Arabian and Australian paediatric hospitals and the variation in radiographers’ knowledge about and attitudes towards CT

摘要

The use of computed tomography (CT) has increased rapidly since the 1970s. CT is a high-dose imaging modality and poses relatively high stochastic and deterministic risks to patients. Paediatric patients are at particular risk due to their smaller body size and the higher radiation sensitivity of their developing organs. Radiographers can play an important role in the reduction of CT radiation dose in paediatric patients, but the literature suggests that radiographers lack understanding of CT radiation dose, and that protocols are rarely modified and updated for children. This study explores and describes Australian and Saudi Arabian paediatric CT radiographers’ knowledge about and attitudes towards CT radiation dose and intervention, and determines the impact of their knowledge and attitudes on protocol selection for paediatric CT scans. The project had three components: a paediatric CT radiographer survey; dosimetry measurements at hospitals; and in-depth interviews with radiographers. The survey findings indicate that Australian paediatric CT radiographers engage in more dose intervention activity than their Saudi Arabian counterparts, receive more initial training, have greater work experience and more continuing professional development (CPD). The knowledge and attitudes of radiographers toward CT dose do not strongly influence their knowledge and practice of CT imaging. Saudi Arabian radiographers were sceptical about the necessity of their CT referrals, unlike Australian radiographers. Both Australian and Saudi Arabian respondents mistakenly believed that the abdomen/pelvis region typically received higher CT doses than the head or chest regions. Dosimetry indicated that CT doses, using the CT departments’ 3-6-year-old protocols, varied considerably between hospitals (head doses – 137.6-528.0 mGy.cm, chest doses – 21.9-92.5 mGy.cm, abdomen/pelvis doses – 24.9-118.0 mGy.cm). Mean head and abdomen/pelvis doses delivered in Saudi Arabian paediatric CT departments are significantly higher than in their Australian equivalents. In Australian paediatric CT departments quality assurance (QA) and machine servicing was performed regularly, whereas most Saudi interviewees reported that no QA was performed. Most Australian interviewees claimed that protocols were modified or updated from machine manufacturers’ defaults, but most Saudi respondents followed the manufacturers’ protocols. Dose intervention is practised in both Australian and Saudi Arabian CT departments, but formal policies are uncommon. Australian radiographers perceived chest and abdomen/pelvis doses as significantly lower (mean 25.7 mGycm and 35.2 mGycm) than actual doses (mean 51.1 mGycm and 68.0 mGycm). There were no significant differences between Saudi Arabians’ perceived and actual doses. Radiographers’ knowledge and understanding of CT dose affect protocols and vary between Australian and Saudi Arabian paediatric hospitals. Australian and Saudi Arabian radiographers have strongly positive attitudes to dose reduction, uninhibited by their lack of knowledge. Australian paediatric CT radiographers have better levels of formal education and more frequent CPD, reflected in their greater willingness to modify CT protocols and alter them for individual cases. However, Australian radiographers suffer from the same misconceptions about paediatric CT dose as less-educated Saudi radiographers, reflecting their poor exposure to paediatric-specific CT within their formal training and CPD. Radiographers should be encouraged and financially supported in CPD and should modify and update CT protocols regularly. Efforts should be directed at improving the knowledge base of radiographers to minimise radiation exposure among paediatric patients. To standardise and reduce dose for paediatric patients, diagnostic reference levels should be established for major anatomical regions that undergo CT.