目的:探讨医用X射线摄影所致受检者入射体表剂量的估算模式,为掌握受检者与患者的剂量水平提供技术支持,并为制定相应的防护措施提供理论依据.方法:对目前已有的普通X射线摄影和数字X射线摄影两大类医用X射线装置中涉及到受检者入射体表剂量估算的研究论文进行归纳和总结,并对相应方法的原理和应用进行探讨,比较各类方法的优点和缺点.结果:普通X射线摄影估算模式的数学模型简单,计算便捷,但相应的曝光参数获取不易,且由于模型相对简化,可能因机型、照射野、受检者及其他摄影条件的差异,导致估算时产生较大的偏差.数字X射线摄影估算模式则不需要进行多余的测量及记录,可根据每次摄影后系统给出的曝光指示值或者DAP值来推算出受检者的入射体表剂量,但在该类方法中,受检部位厚度的不确定性会致使结果存在较大差异.结论:目前现存的用于估算医用X射线摄影所致受检者入射体表剂量的模型仍存在较大差异和不足,其中数字X射线摄影估算方法有较大应用前景,仍有待进一步发展和探索.%Objective:This review investigates the calculation method of patients' entrance surface dose from diagnostic X-ray procedures,in order to provide technique support for patients' dose level estimation and guidance for relevant protocols.Methods:Reviewing the papers focused on the entrance surface dose estimation methods for traditional film-screen systems and digital X-ray systems and discussing their theories and applications.Also,the advantages and disadvantages of these methods were compared.Results:The methods for traditional X-ray systems were fairly easy comparing to obtaining of the exposure parameters.And due to the simplification of these models,the estimation results might vary largely because of the differences in modalities,field size,patients and other exposure conditions.The methods for digital X-ray systems,which acquire the needed parameters directly from the X-ray systems,don't need any extra measurements.However,the uncertainty of the patients' body part thickness might lead to some differences in estimation results.Conclusions:The existed estimation methods of the entrance surface dose for diagnostic X-ray procedures remain certain differences and disadvantages.Among those methods,the estimation methods for digital X-ray systems might have great prospects in the future,but further developments and researches are still needed.
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