X射线诊断所致受检者剂量的估算模式研究
|
摘要
【目的】随着医疗卫生事业的迅速发展，放射学新技术和新设备的不断涌现并日益广泛普及，因疾病诊疗和健康保健等需要而接受X射线诊断检查的受检者越来越多，导致了全民集体剂量的持续不断增加。作为医疗照射防护的基础，深入研究评价各种X射线诊断所致受检者的剂量，已成为放射医学与防护、医学物理等学科领域的热点和重点研究课题。通常基于现场测量来评价X射线诊断所致集体剂量的研究方法代价太高，难以得到普及应用。为此，本项研究在充分的现状调研与分析基础上，另辟思路，探索建立基于各种X射线诊断设备的工作条件和技术参数来估算主要X射线诊断类型所致受检者剂量的模式，为方便开展评价医疗照射的集体剂量提供新方法。
【方法】根据不同类型X射线诊断的特点，本研究选取影响面大、发展快且所致受检者剂量较大的三个主要类型(普通和数字化X射线摄影、X射线计算机断(体)层摄影)作为重点对象，分别通过以下方法开展研究：(1)普通X射线摄影：先由实验研究建立X射线输出量空气比释动能与管电压和毫安秒的关系，进一步考虑其对总过滤和高压发生器类型修正；利用蒙特卡罗方法计算不同照射条件下的反散射因子；最终建立受检者入射体表剂量和有效剂量的估算模式、编写相应计算软件。(2)数字化X射线摄影：先由理论推导曝光指示值与入射体表剂量的定性关系模式；通过实验研究掌握相关参数的数值，并探讨管电压与探测器能量相应对相关参数的修正；最后建立曝光指示值和受检者入射体表剂量的关系模式。(3)X射线计算机体层摄影：基于国外最先进的数字参考人体素模型和CT机的蒙卡模型，自行建立在参考条件下每层扫描所致受检者器官剂量的基础数据库；探讨CT机型，扫描用管电压、mAs值、螺距因子和准直宽度等因素对辐射剂量的影响，通过相关修正建立可计算任意扫描条件下的器官剂量和有效剂量的估算模式。同时，本课题还建立了利用CT扫描的各种技术条件和参数估算CT扫描的剂量长度乘积(DLP)，并结合不同部位CT扫描所对应的剂量转换系数计算有效剂量的方法，编写了基于该方法的有效剂量估算软件。本研究对各种估算模式的计算结果验证主要利用仿真人体模实施，主要是通过在体模表面和内部布放玻璃剂量计来测量或基于测量值计算入射体表剂量和器官吸收剂量，在计算有效剂量时采用了最新推荐的组织权重因子。
【结果】(1)建立了利用X射线摄影技术参数(包括管电压、管电流和曝光时间乘积、总过滤、焦皮距、高压发生器类型和照射野)估算普通X射线摄影所致受检者的入射体表剂量和有效剂量的数学模式。验证结果表明：在所开展的验证条件下，入射体表剂量的计算值与实验测量值的相对偏差为-12．1％～4．5％；有效剂量的计算值与体模实验模拟测量值相对偏差介于-29．2％～31．4％之间。(2)建立了利用曝光量指示估算数字化X射线摄影所致受检者入射体表剂量的数学模式。验证结果表明：在本研究的实验条件下，入射体表剂量的模式计算值与测量值之间的相对偏差介于-22．1％～19．2％之间。(3)建立了利用蒙特卡罗方法和DLP方法估算CT扫描所致受检者剂量的模式。验证结果表明：蒙特卡罗方法计算扫描野范围内的器官剂量与体模实验测量值的偏差在17．7％～32．2％之间，有效剂量的相对偏差为-9．8％～5．5％；用DLP模式计算得到有效剂量与体模实验值的偏差介于-10．8％～13．3％之间。
【结论】在常规辐射防护剂量学的允许误差范围内，本项研究建立所有X射线诊断类型所致受检者剂量的估算模式基本均能满足辐射剂量评价的精度要求。基于三大类X射线诊断设备的工作条件和技术参数而建立的上述受检者剂量估算模式，可为大范围开展X射线诊断所致受检者剂量水平调查和评价其所致集体剂量提供了一种便捷的方法，具有很高的推广应用价值，对相关学科发展也具有重要的理论意义。
Purpose With the rapid development of medical care,new radiological technologiesand new equipments have made medical X-ray procedures much more popular.Therefore,more and more patients are involved in the X-ray diagnostic examinations,which lead to the collective dose keeping increasing.As a basis of radiation protection,the radiation doses from various X-ray diagnostic procedures has become animportant research topic in the fields of radiation medicine,radiation protection,medical physics and other subjects.The conventional methodology based on fieldmeasurements was too high a price for evaluating the collective dose from X-raydiagnosis,and thus it is difficult to be widely spread.Based on the comprehensiveinvestigation and analysis of the related studies,the aim of this study was to exploreand establish some corresponding computational models based on the equipments andexposure parameters of the main types of X-ray diagnostic procedures,and to providea new methodology for convenient assessment of the collective dose from medicalexposure.
Methods According to the characteristics of different X-ray diagnostic procedures,the main concern of this study are the conventional X-ray radiography,digital X-rayradiography and X-ray computed tomography,as they are more widely used or rapidlyincreasing and higher dose contributors.(1) For the conventional X-ray radiography,the air kerma of X-ray output was experimentally quantified with the factors of tubevoltage and tube current and exposure time product (mAs) first,then the correction ofthe total filtration and generator type was made,having calculated the back-scatteringfactors (BSF) under different exposure conditions by using Monte Carlo method,amathematical model for estimating patient dose including the entrance surface dose(ESD) and effective dose was built and a software was programmed.(2) For thedigital X-ray photography,the relationship between the ESD and the exposure indexwas theoretically qualified first,the parameters in the qualified formula wereexperimentally determined,having considered the influence of tube voltage andenergy response of the detector (Imaging Plate) on the parameters mentioned above,a mathematical model was established for estimating the ESD from the exposure index(3) For X-ray computed tomography,based on the most advanced voxel phantomsand CT models,a organ doses database of for each slice scan in reference conditionswas built first,having corrected the influence of scanner type,tube voltage,mAs,pitch factor and collimator width on the radiation dose,a computational model forcalculating both organ doses and effective doses was built.Furthermore,anothermethod was also established for calculating the effective dose by multiplying the doselength product (DLP) and the corresponding dose conversion factors,and softwarewas also programmed according to this method in this study.The DLP was evaluatedbased on the database of various technical conditions and parameters of CT scanning.In this study,experimental verifications of the computational models were mainlycarried out through the in-phantom measurements with the radiophotoluminescentglass dosimeters (RPLGD).The ESD was directly given,and the organ doses wereestimated from the measured value of RPLGD.New tissue weighting factors wereused to calculate the effective dose with the measured organ doses.
Results (1) A new mathematical model was built for estimating the ESD andeffective dose from conventional X-ray radiography by using technique parameters,including the tube voltage,mAs,total filtration,focal skin distance,generator typeand exposure field.Experimental verifications showed that the deviation between thecalculated ESD and the measured ones ranged from -12.1% to 4.5% and the deviationof the effective dose were in -29.2%～31.4%.(2) A mathematical model wasestablished for calculating the ESD with the exposure index of digital X-rayphotography.The experimental verifications showed that the deviation between thecalculated ESD and the measured ones ranged from -22.1% to 19.2%.(3) Twomethods were established for estimating the patient dose in X-ray computedtomography.For the method based on Monte Carlo simulation,experimentalverifications showed that the deviation between the calculated organ doses and thein-phantom measured ones were in a ranged of-17.7%～32.2%,and the deviation ofthe effective dose ranged from -9.8% to 5.5%.For the method based on the DLPmodel calculation,experimental verifications showed that the deviation of effectivedose ranged from -10.8%～13.3%.
Conclusion Compared with the generally acceptable error in the field of radiationprotection dosimetry,all computational models built in the study are basicallysatisfied for estimating patient doses in the diagnostic X-ray examinations.The above-mentioned computational models,built with the working conditions andtechnical parameters in the three categories of X-ray diagnostic equipment,provideconvenient ways for large-scale surveys of patient dose level and for assessment ofthe collective dose from X-ray diagnosis.They have a high value for extendingapplication,and they also possess great theoretical significance for the developmentof relevant disciplines.
【方法】根据不同类型X射线诊断的特点，本研究选取影响面大、发展快且所致受检者剂量较大的三个主要类型(普通和数字化X射线摄影、X射线计算机断(体)层摄影)作为重点对象，分别通过以下方法开展研究：(1)普通X射线摄影：先由实验研究建立X射线输出量空气比释动能与管电压和毫安秒的关系，进一步考虑其对总过滤和高压发生器类型修正；利用蒙特卡罗方法计算不同照射条件下的反散射因子；最终建立受检者入射体表剂量和有效剂量的估算模式、编写相应计算软件。(2)数字化X射线摄影：先由理论推导曝光指示值与入射体表剂量的定性关系模式；通过实验研究掌握相关参数的数值，并探讨管电压与探测器能量相应对相关参数的修正；最后建立曝光指示值和受检者入射体表剂量的关系模式。(3)X射线计算机体层摄影：基于国外最先进的数字参考人体素模型和CT机的蒙卡模型，自行建立在参考条件下每层扫描所致受检者器官剂量的基础数据库；探讨CT机型，扫描用管电压、mAs值、螺距因子和准直宽度等因素对辐射剂量的影响，通过相关修正建立可计算任意扫描条件下的器官剂量和有效剂量的估算模式。同时，本课题还建立了利用CT扫描的各种技术条件和参数估算CT扫描的剂量长度乘积(DLP)，并结合不同部位CT扫描所对应的剂量转换系数计算有效剂量的方法，编写了基于该方法的有效剂量估算软件。本研究对各种估算模式的计算结果验证主要利用仿真人体模实施，主要是通过在体模表面和内部布放玻璃剂量计来测量或基于测量值计算入射体表剂量和器官吸收剂量，在计算有效剂量时采用了最新推荐的组织权重因子。
【结果】(1)建立了利用X射线摄影技术参数(包括管电压、管电流和曝光时间乘积、总过滤、焦皮距、高压发生器类型和照射野)估算普通X射线摄影所致受检者的入射体表剂量和有效剂量的数学模式。验证结果表明：在所开展的验证条件下，入射体表剂量的计算值与实验测量值的相对偏差为-12．1％～4．5％；有效剂量的计算值与体模实验模拟测量值相对偏差介于-29．2％～31．4％之间。(2)建立了利用曝光量指示估算数字化X射线摄影所致受检者入射体表剂量的数学模式。验证结果表明：在本研究的实验条件下，入射体表剂量的模式计算值与测量值之间的相对偏差介于-22．1％～19．2％之间。(3)建立了利用蒙特卡罗方法和DLP方法估算CT扫描所致受检者剂量的模式。验证结果表明：蒙特卡罗方法计算扫描野范围内的器官剂量与体模实验测量值的偏差在17．7％～32．2％之间，有效剂量的相对偏差为-9．8％～5．5％；用DLP模式计算得到有效剂量与体模实验值的偏差介于-10．8％～13．3％之间。
【结论】在常规辐射防护剂量学的允许误差范围内，本项研究建立所有X射线诊断类型所致受检者剂量的估算模式基本均能满足辐射剂量评价的精度要求。基于三大类X射线诊断设备的工作条件和技术参数而建立的上述受检者剂量估算模式，可为大范围开展X射线诊断所致受检者剂量水平调查和评价其所致集体剂量提供了一种便捷的方法，具有很高的推广应用价值，对相关学科发展也具有重要的理论意义。
Purpose With the rapid development of medical care,new radiological technologiesand new equipments have made medical X-ray procedures much more popular.Therefore,more and more patients are involved in the X-ray diagnostic examinations,which lead to the collective dose keeping increasing.As a basis of radiation protection,the radiation doses from various X-ray diagnostic procedures has become animportant research topic in the fields of radiation medicine,radiation protection,medical physics and other subjects.The conventional methodology based on fieldmeasurements was too high a price for evaluating the collective dose from X-raydiagnosis,and thus it is difficult to be widely spread.Based on the comprehensiveinvestigation and analysis of the related studies,the aim of this study was to exploreand establish some corresponding computational models based on the equipments andexposure parameters of the main types of X-ray diagnostic procedures,and to providea new methodology for convenient assessment of the collective dose from medicalexposure.
Methods According to the characteristics of different X-ray diagnostic procedures,the main concern of this study are the conventional X-ray radiography,digital X-rayradiography and X-ray computed tomography,as they are more widely used or rapidlyincreasing and higher dose contributors.(1) For the conventional X-ray radiography,the air kerma of X-ray output was experimentally quantified with the factors of tubevoltage and tube current and exposure time product (mAs) first,then the correction ofthe total filtration and generator type was made,having calculated the back-scatteringfactors (BSF) under different exposure conditions by using Monte Carlo method,amathematical model for estimating patient dose including the entrance surface dose(ESD) and effective dose was built and a software was programmed.(2) For thedigital X-ray photography,the relationship between the ESD and the exposure indexwas theoretically qualified first,the parameters in the qualified formula wereexperimentally determined,having considered the influence of tube voltage andenergy response of the detector (Imaging Plate) on the parameters mentioned above,a mathematical model was established for estimating the ESD from the exposure index(3) For X-ray computed tomography,based on the most advanced voxel phantomsand CT models,a organ doses database of for each slice scan in reference conditionswas built first,having corrected the influence of scanner type,tube voltage,mAs,pitch factor and collimator width on the radiation dose,a computational model forcalculating both organ doses and effective doses was built.Furthermore,anothermethod was also established for calculating the effective dose by multiplying the doselength product (DLP) and the corresponding dose conversion factors,and softwarewas also programmed according to this method in this study.The DLP was evaluatedbased on the database of various technical conditions and parameters of CT scanning.In this study,experimental verifications of the computational models were mainlycarried out through the in-phantom measurements with the radiophotoluminescentglass dosimeters (RPLGD).The ESD was directly given,and the organ doses wereestimated from the measured value of RPLGD.New tissue weighting factors wereused to calculate the effective dose with the measured organ doses.
Results (1) A new mathematical model was built for estimating the ESD andeffective dose from conventional X-ray radiography by using technique parameters,including the tube voltage,mAs,total filtration,focal skin distance,generator typeand exposure field.Experimental verifications showed that the deviation between thecalculated ESD and the measured ones ranged from -12.1% to 4.5% and the deviationof the effective dose were in -29.2%～31.4%.(2) A mathematical model wasestablished for calculating the ESD with the exposure index of digital X-rayphotography.The experimental verifications showed that the deviation between thecalculated ESD and the measured ones ranged from -22.1% to 19.2%.(3) Twomethods were established for estimating the patient dose in X-ray computedtomography.For the method based on Monte Carlo simulation,experimentalverifications showed that the deviation between the calculated organ doses and thein-phantom measured ones were in a ranged of-17.7%～32.2%,and the deviation ofthe effective dose ranged from -9.8% to 5.5%.For the method based on the DLPmodel calculation,experimental verifications showed that the deviation of effectivedose ranged from -10.8%～13.3%.
Conclusion Compared with the generally acceptable error in the field of radiationprotection dosimetry,all computational models built in the study are basicallysatisfied for estimating patient doses in the diagnostic X-ray examinations.The above-mentioned computational models,built with the working conditions andtechnical parameters in the three categories of X-ray diagnostic equipment,provideconvenient ways for large-scale surveys of patient dose level and for assessment ofthe collective dose from X-ray diagnosis.They have a high value for extendingapplication,and they also possess great theoretical significance for the developmentof relevant disciplines.
引文
[1]Wall BF，Kendall GM，Edwards AA，et al．What are the risks from medical X-rays and other low dose radiation?[J]．Br J Radiol，2006，79(940)：285-294．
[2]Geleijns J，Wondergem J．X-ray imaging and the skin：Radiation biology，patient dosimetry and observed effects[J]．Radiat Prot Dosim，2005，114(1-3)：121-125．
[3]郑钧正．电离辐射医学应用的防护与安全[M]．北京：原子能出版社，2009：111-113．
[4]潘自强，程建平等．电离辐射防护和辐射源安全(上册)[M]．北京：原子能出版社，2007：312．
[5]郑钧正．放射防护与放射学的发展[J]．中华放射学杂志，2003，37(纪念特刊)：100-105．
[6]Pablo Jim(?)nez．Emerging challenges in the management of medical exposures [PDF]．：http：//www．irpal2．org．ar，2009-4-10．
[7]UNSCEAR．Source and Effects of Ionizing Radiation[R]．New York：United Nations，2000．
[8]ICRP．Managing Patient Dose in Computed Tomography．ICRP Publication 87[M]．Oxford：Pergamon Press，2001．
[9]郑钧正，贺庆华，李述唐等．我国电离辐射医学应用的基本现状[J]．中华放射医学与防护杂志，20(增刊)：s7-14，2000．
[10]郑钧正，岳保荣，李述唐等．我国“九五”期间X射线诊断的医疗照射频率水平[J]．中华放射医学与防护杂志，20(增刊)：s14-18，2000．
[11]岳保荣，郑钧正，李述唐等．我国“九五”期间X射线诊断所致受检者的体表剂量水平，中华放射医学与防护杂志，20(增刊)：s 18-23，2000．
[12]Edmonds IR．Calculation of patient skin dose from diagnostic X-ray procedures [J]．Br J Radiol，1984，57(680)：733-734．
[13]George J，Eatough JP，Mountford PJ，et al．Patient dose optimization in plain radiography based on standard exposure factors[J]．Br J Radiol，2004，77(922)： 858-863．
[14]Warren-Forward H，Arthur L，Hobson L，Skinner R，Watts A，Clapham K，Lou D，Cook A．An assessment of exposure indices in computed radiography for the posterior-anterior chest and the lateral lumbar spine[J]．Br J Radiol，2006，80 (949)：26-31．
[15]Nishizawa K，Mori S，Ohno M，Yanagawa N，Yoshida T，Akahane K，Iwai K， Wada S．Patient dose estimation for multi-detector-row CT examinations[J]． Radiat Prot Dosim，2008，128(1)：98-105．
[16]Brenner DJ，Hall EJ．Computed Tomography—An Increasing Source of Radiation Exposure[J]．N Engl J Med，2007，357：2277-2284．
[17]DeMarco JJ，Cagnon CH，Cody DD，Stevens DM，McCollough CH，O'Daniel J， McNitt-Gray MF．A Monte Carlo based method to estimate radiation dose from multidetector CT(MDCT)：cylindrical and anthropomorphic phantoms[J]．Phys Med Biol，2005，50(17)：3989-4004．
[18]Jarry G，DeMarco JJ，Beifuss U，Cagnon CH，McNitt-Gray MF．A Monte Carlo-based method to estimate radiation dose from spiral CT：from phantom testing to patient-specific models[J]．Phys Med Biol，2003，48(16)：2645-2663．
[19]DeMarco JJ，Cagnon CH，Cody DD，Stevens DM，McCollough CH，Zankl M， Angel E，McNitt-Gray MF．Estimating radiation doses from multidetector CT using Monte Carlo simulations：effects of different size voxelized patient models on magnitudes of organ and effective dose[J]．Phys Med Biol，2007， 52(9)：2583-2597．
[20]中国报告大厅．2007年医用X射线设备行业现状及08-10年行业投资分析．：http：//www．chinabgao．com/reports/29539．html，2008．
[21]Schellingerhout D，Chew FS，Mullins ME，and Gonzalez RG．Projected Digital Radiologic Images for Teaching：Balance of Image Quality with Data Size Constraints[J]．Acad Radiol，2002，9(2)：157-162．
[22]GB 18871-2002，电离辐射防护与辐射源安全基本标准[S]．北京：中国标准出版社，2002．
[23]中华人民共和国国家职业卫生标准．医疗照射放射防护名词术语，GBZ/T146—2002[S]．北京：人民卫生出版社，2006．
[24]郑钧正，贺青华，李述唐，等．“九五”期间全国医疗照射水平调查研究[J]．中华放射医学与防护杂志，2000，20(S)：s2-s7．
[25]朱志贤，唐文祥，韩发明，等．模拟人体反散射材料试验研究[J]．中国辐射卫生，2001，10(4)：198-199．
[26]Shrimpton PC．Calculation of patient skin dose from diagnostic X-ray procedures[J]．Br J Radiol，1985，58(689)：483-485．
[27]#12
[28]Aoki K，Koyama M．Measurement of backscattered x-ray spectra at the water surface in the energy range 60 kV to 120 kV[J]．Phys Med Biol，2002，47(7)： 1205-1217．
[29]Patrocinio HJ，Bissonnette JP，Bussiere MR，et al．Limiting values of backscatter factors for low-energy x-ray beams[J]．Phys Med Biol，1996， 41(2)：239-253．
[30]Petoussi-Henss N，Zankl M，Drexler G，et al．Calculation of backscatter factors for diagnostic radiology using Monte Carlo methods[J]．Phys Med Biol，1998， 43(8)：2237-2250．
[31]Faulkne K，Ortiz-Lopez P Vano．Patient dosimetry in diagnostic and interventional radiology：A practical approach using trigger levels[J]．Radiat Prot Dosim，2006，117(1-3)：166-168．
[32]ICRP．1990 Recommendations of the ICRP，ICRP Publication 60[M]．Oxford： Pergamon Press，1991．
[33]ICRP．2007 Recommendations of the ICRP，ICRP Publication 103[M]．Oxford： Pergamon Press，2008．
[34]Hart D，Jones DG，Wall BF．Estimation of effective dose in radiology from entrance surface dose and dose area product measurements[R]．NRPB-262， Chilton：NRPB，1994．
[35]中华人民共和国国家标准．X线诊断中受检者器官剂量的估算方法，GB/T16137-1995[S]．1996．
[36]ICRP．Protection of the Patient in Diagnostic Radiology，ICRP Publication 34[M]．Oxford：Pergamon Press，1982．
[37]Ioppolo JL，Price RI，Tuchyna T，et al．Diagnostic x-ray dosimetry using Monte Carlo simulation[J]．Phys Med Biol，2002，47(10)：1707-1720．
[38]International Atomic Energy Agency．IAEA Technical Reports Series 277， Absorbed dose determination in photon and electron beams[R]．IAEA，Vienna， 1987．
[39]苏森龄．X射线和γ射线防护手册：诊断与科研用[M]．贵阳：贵州人民出版社，1982：27．
[40]李士骏著．电离辐射剂量学[M]．原子能出版社，1986：133．
[41]鱼红亮，孙亮，刘海宽．医用诊断X射线反散射因子的蒙特卡罗方法计算[J]．核技术．2009，已录用．
[42]Briesmeister J F．MCNP-A General Monte Carlo N-particle Transport Code[M] Report LA-12625，Version 4B，Los Almos National Laboratory．1997．
[43]Klevenhagen S C．The build-up of backscatter in the energy range 1 mm Al to 8 mm Al HVL[J]．Phys Med Biol，1982，27：1035-1043．
[44]ICRU．Fundamental quantities and units for ionizing radiation[R]．ICRU Report 60．ICRU Bethesda，MD．USA，1998．
[45]Hubbell JH．Photon mass attenuation and energy absorption coefficients from 1 keV to 20 MeV[J]．Int．J．Appl Radiat Isot．1982，33：1269-1290．
[46]N Petoussi-Henss．Calculation of backscatter factors for diagnostic radiology using Monte Carlo methods[J]．Phys Med Biol，1998，43：2237-2250．
[47]李黎军，宋宏羽，潘洁森，程媛．光子束不规则射野的等效方野计算方法[J]．中华放射医学与防护杂志．2005，25(4)：366-367．
[48]YASUDA H，FUJITAKA K．Solid-state integrating detectors as an indicator of biological doses from HZE particles[J]．Adv Space Res，2002，30(4)：927-932．
[49]Araki F，Moribe N，Shimonobu T，et al．Dosimetric properties of radiophotoluminescent glass rod detector in high-energy photo beams from a liner accelerator and Cyber-Knife[J]．Med Phys，2004，31(7)：1980-1985．
[50]ZHUO W，LIU W，HUANG G，ZHU G，MA G．Comparisons of dosimetric properties between GD-300 series of radiophotoluminescent glass detectors and GR-200 series of thermoluminescent detectors[J]．Nuclear Science and Techniques．2007，18(6)：362-365．
[51]范家栋，谢敬霞．CT诊断学基础(第二版)[M]．北京：北京医科大学出版社，2001：4-5．
[52］辛晓峰，修清玉，施毅，等．高分辨率CT对慢性哮喘患者肺密度CT值测定的定量分析研究[J]．医学研究生学报，2006，19(4)：352-355．
[53]ICRP．Basic anatomical & physiological data for use in radiological protection： the skeleton[M]．ICRP Publication 70．Oxford：Pergamon Press，1996．
[54]ICRP．Managing Patient Dose in Digital Radiology[M]．ICRP Publication 93． Oxford：Pergamon Press，2005．
[55]Peters SE，Brennan PC．Digital radiography：are the manufacturers' settings too high? Optimisation of the Kodak digital radiography system with aid of the computed radiography dose index[J]．Eur Radio]，2002，12(9)：2381-1287．
[56]Warren-Forward H，Arthur L，Hobson L，et al．An assessment of exposure indices in computed radiography for the posterior-anterior chest and the lateral lumbar spine[J]．Br J Radiol，2007，80(949)：26-31
[57]AAPM．Acceptance testing and quality control of photostimulable storage phosphor imaging systemsIR]．AAPM Report No．93．Report of Task Group 10， College Park，MD．USA，2006．
[58]Huda W，Rill LN，Bruner AP．Relative speeds of Kodak computed radiography phosphors and screen-film systems[J]．Med Phys，1997，24：1621-1628．
[59]Willis CE．Strategies for dose reduction in ordinary radiographic examinations using CR and DR[J]．Pediatr Radiol，2004，34：S196-S200．
[60]ICRP．Managing Patient Dose in Computed Tomography[M]．ICRP Publication 87．Oxford：Pergamon Press，2001．
[61]ICRP．Managing Patient Dose in Multi-Detector Computed Tomography (MDCT)[M]．ICRP Publication 102．Oxford：Pergamon Press，2007．
[62]Mettler FA Jr，Thomadsen BR，Bhargavan M，Gilley DB，Gray JE，Lipoti JA， McCrohan J，Yoshizumi TT，Mahesh M．Medical radiation exposure in the U．S．in 2006：preliminary results[J]．Health Phys，2008，95(5)：502-507．
[63]路鹤晴．上海市民1996,1998年X射线诊断照射频率调查[J]．环境与职业医学杂志．2003，20(6)：454-456．
[64]路鹤晴．X射线CT医疗照射剂量水平评价模式与辐射剂量影响因素研究[D]．上海：复旦大学，2008．
[65]Mettler FA Jr，Wiest PW，Locken JA，et al．CT scanning：patterns of use and dose[J]．J Radiol Prot，2000，20(4)：353-359．
[66]Hughes JS，O'Riordon MC．Radiation exposure of the UK population：1993 review[J]．Chilton：National Radiological Protection Board，1993．
[67]Shrimpton PC，Edyvean S．CT scanner dosimetry[J]．Br J Radiol，1998， 71(841)：1-3．
[68]郑钧正．加强医疗照射防护的重点工作［[J]．中华放射医学与防护杂志，2005，25(2)：105-106．
[69]IEC．Evaluation and routine testing in medical imaging departments-Part 3-5： Acceptance tests—imaging performance of computed tomography X-ray equipment．IEC 61223-3-5[S]．2004．
[70]中华人民共和国国家职业卫生标准．X射线计算机断层摄影放射卫生防护标准，GBZ 165-2005[S]．北京：人民卫生出版社，2006．
[71]McNitt-Gray MF．AAPM/RSNA Physics Tutorial for Residents：Topics in CT． Radiation dose in CT[J]．Radiographics，2002，22(6)：1541-1553．
[72]Irwan R，Vries H．de，Sijens P．The Impact of Scan Length on the Exposure Levels in 16-and 64-Row Multidetector Computed Tomography：A Phantom Study[J]．Acad Radiol，2008，15(9)：1142-1147．
[73]DeMarco JJ，Cagnon CH，Cody DD，et al．Estimating radiation doses from multidetector CT using Monte Carlo simulations：effects of different size voxelized patient models on magnitudes of organ and effective dose[J]．Phys Med Biol，2007，52(9)：2583-2597．
[74]Alonso M，Barriuso T，Castaneda，MJ，et al．Monte carlo estimation of absorbed dose to organs in computed tomography[J]．Health Phys，2002，82(2)：233-239．
[75]CEC．Quality criteria for computed tomography，European guidelines．EUR 16262[S]．Luxembourg：Commission of the European Communities，1999．
[76]ZHUO W，LIU W，HUANG G，ZHU G，MA G．Comparisons of dosimetric properties between GD-300 series of radiophotoluminescent glass detectors and GR-200 series of thermoluminescent detectors[J]．Nuclear Science and Techniques．2007，18(6)：362-365．
[77]Pelowitz DB．MCNPX User's Manual，Version 2．5．0[R]．Los Alamos National Laboratory，Report No．LA-UR-02-2607，2005．
[78]石成玉，徐榭，王进亮，白净．新一代虚拟人体解剖模型开发研究及其在放射医学及防护中的应用[J]．中华放射医学与防护杂志，2005，25(2)：201-205．
[79]张居营，徐榭，石成玉．四维动态数字人体模型的开发及其在放疗计划中评估器官呼吸运动影响的研究[J]．中国医学影像技术，2006，22(9)：1301-1305．
[80]Cristy M，Eckerman K．Specific absorbed f ractions of energy at various ages from internal photons sources[R]．Oak Ridge：Oak Ridge National Laboratory，1987．
[81]Williams G，Zankl M，Abmayr W，et al．The calculation of dose from external photon exposures using reference and realistic human phantoms and Monte Carlo methods．Phys Med Biol，1986，31：449-452．
[82]Xu XG，Chao TC，Bozkurt A．VIP-Man：an image-based whole body adult male model constructed from color photographs of the visible human project for multi-particle Monte Carlo calculations[J]．Health Phys，2000，78(5)：476-486．
[83]Zhang JY，Na YH，Xu XG．Development of Whole-Body Phantoms Representing An Average Adult Male and Female Using Surface-Geometry Methods．Med Phys，2008，35(6)：2875．
[84]Zhang J，Na Y，Xu GX．Development of a pair of mesh-based adult male and female computational phantoms and Calculations of organ doses for monoenergetic photon beams．Phys Med Biol．(In press)
[85]ICRP Publication 89：Basic Anatomical and Physiological Data for Use in Radiological Protection: Reference Values[R]. Ann ICRP 2003; 32: 1-277
[86] ICRU Report 46. Photon, electron, proton and neutron interaction data for body tissues[R]. ICRU, Bethesda, MD., USA, 1992.
[87] Gu J, Bednarz B, Caracappa PF, Xu GX. The development, validation and application of a multi-detector CT (MDCT) scanner model for assessing organ doses to the pregnant patient and her fetus using Monte Carlo methods. Phys Med Biol, 2009, 54:2699-2717..
[88] DeMarco JJ, Cagnon CH, Cody DD, Stevens DM, McCollough CH, O'Daniel J and McNitt-Gray MF. A Monte Carlo based method to estimate radiation dose from multidetector CT (MDCT): cylindrical and anthropomorphic phantoms[J].Phys Med Biol, 2005, 50: 3989-4004.
[89] Jarry G, DeMarco JJ, Beifuss U, Cagnon CH and McNitt-Gray MF. A Monte Carlo-based method to estimate radiation dose from spiral CT: from phantom testing to patient-specific models[J]. Phys Med Biol, 2003,48: 2645-2663.
[90] Schlattl H, Zankl M, Petoussi-Henss N. Organ dose conversion coefficients for voxel models of the reference male and female from idealized photon exposures. Phys Med Biol, 2007,52:2123-2145.
[91] King SD, Spiers FW. Photoelectron enhancement of the absorbed dose from X rays to human bone marrow: experimental and theoretical studies. Br J Radiol,1985, 58(688):345-356.
[92] Lee C, Lee C, Shah AP, Bolch WE. An assessment of bone marrow and bone endosteum dosimetry methods for photon sources. Phys Med Biol, 2006,51:5391-5407.
[93] Lewis M A,Edyvean S,Sassi S A,et al.Estimating patient dose on current CT scanners:results of the IMPACT CT dose survey[J].RAD Mag, 2000,8:17-18.
[2]Geleijns J，Wondergem J．X-ray imaging and the skin：Radiation biology，patient dosimetry and observed effects[J]．Radiat Prot Dosim，2005，114(1-3)：121-125．
[3]郑钧正．电离辐射医学应用的防护与安全[M]．北京：原子能出版社，2009：111-113．
[4]潘自强，程建平等．电离辐射防护和辐射源安全(上册)[M]．北京：原子能出版社，2007：312．
[5]郑钧正．放射防护与放射学的发展[J]．中华放射学杂志，2003，37(纪念特刊)：100-105．
[6]Pablo Jim(?)nez．Emerging challenges in the management of medical exposures [PDF]．：http：//www．irpal2．org．ar，2009-4-10．
[7]UNSCEAR．Source and Effects of Ionizing Radiation[R]．New York：United Nations，2000．
[8]ICRP．Managing Patient Dose in Computed Tomography．ICRP Publication 87[M]．Oxford：Pergamon Press，2001．
[9]郑钧正，贺庆华，李述唐等．我国电离辐射医学应用的基本现状[J]．中华放射医学与防护杂志，20(增刊)：s7-14，2000．
[10]郑钧正，岳保荣，李述唐等．我国“九五”期间X射线诊断的医疗照射频率水平[J]．中华放射医学与防护杂志，20(增刊)：s14-18，2000．
[11]岳保荣，郑钧正，李述唐等．我国“九五”期间X射线诊断所致受检者的体表剂量水平，中华放射医学与防护杂志，20(增刊)：s 18-23，2000．
[12]Edmonds IR．Calculation of patient skin dose from diagnostic X-ray procedures [J]．Br J Radiol，1984，57(680)：733-734．
[13]George J，Eatough JP，Mountford PJ，et al．Patient dose optimization in plain radiography based on standard exposure factors[J]．Br J Radiol，2004，77(922)： 858-863．
[14]Warren-Forward H，Arthur L，Hobson L，Skinner R，Watts A，Clapham K，Lou D，Cook A．An assessment of exposure indices in computed radiography for the posterior-anterior chest and the lateral lumbar spine[J]．Br J Radiol，2006，80 (949)：26-31．
[15]Nishizawa K，Mori S，Ohno M，Yanagawa N，Yoshida T，Akahane K，Iwai K， Wada S．Patient dose estimation for multi-detector-row CT examinations[J]． Radiat Prot Dosim，2008，128(1)：98-105．
[16]Brenner DJ，Hall EJ．Computed Tomography—An Increasing Source of Radiation Exposure[J]．N Engl J Med，2007，357：2277-2284．
[17]DeMarco JJ，Cagnon CH，Cody DD，Stevens DM，McCollough CH，O'Daniel J， McNitt-Gray MF．A Monte Carlo based method to estimate radiation dose from multidetector CT(MDCT)：cylindrical and anthropomorphic phantoms[J]．Phys Med Biol，2005，50(17)：3989-4004．
[18]Jarry G，DeMarco JJ，Beifuss U，Cagnon CH，McNitt-Gray MF．A Monte Carlo-based method to estimate radiation dose from spiral CT：from phantom testing to patient-specific models[J]．Phys Med Biol，2003，48(16)：2645-2663．
[19]DeMarco JJ，Cagnon CH，Cody DD，Stevens DM，McCollough CH，Zankl M， Angel E，McNitt-Gray MF．Estimating radiation doses from multidetector CT using Monte Carlo simulations：effects of different size voxelized patient models on magnitudes of organ and effective dose[J]．Phys Med Biol，2007， 52(9)：2583-2597．
[20]中国报告大厅．2007年医用X射线设备行业现状及08-10年行业投资分析．：http：//www．chinabgao．com/reports/29539．html，2008．
[21]Schellingerhout D，Chew FS，Mullins ME，and Gonzalez RG．Projected Digital Radiologic Images for Teaching：Balance of Image Quality with Data Size Constraints[J]．Acad Radiol，2002，9(2)：157-162．
[22]GB 18871-2002，电离辐射防护与辐射源安全基本标准[S]．北京：中国标准出版社，2002．
[23]中华人民共和国国家职业卫生标准．医疗照射放射防护名词术语，GBZ/T146—2002[S]．北京：人民卫生出版社，2006．
[24]郑钧正，贺青华，李述唐，等．“九五”期间全国医疗照射水平调查研究[J]．中华放射医学与防护杂志，2000，20(S)：s2-s7．
[25]朱志贤，唐文祥，韩发明，等．模拟人体反散射材料试验研究[J]．中国辐射卫生，2001，10(4)：198-199．
[26]Shrimpton PC．Calculation of patient skin dose from diagnostic X-ray procedures[J]．Br J Radiol，1985，58(689)：483-485．
[27]#12
[28]Aoki K，Koyama M．Measurement of backscattered x-ray spectra at the water surface in the energy range 60 kV to 120 kV[J]．Phys Med Biol，2002，47(7)： 1205-1217．
[29]Patrocinio HJ，Bissonnette JP，Bussiere MR，et al．Limiting values of backscatter factors for low-energy x-ray beams[J]．Phys Med Biol，1996， 41(2)：239-253．
[30]Petoussi-Henss N，Zankl M，Drexler G，et al．Calculation of backscatter factors for diagnostic radiology using Monte Carlo methods[J]．Phys Med Biol，1998， 43(8)：2237-2250．
[31]Faulkne K，Ortiz-Lopez P Vano．Patient dosimetry in diagnostic and interventional radiology：A practical approach using trigger levels[J]．Radiat Prot Dosim，2006，117(1-3)：166-168．
[32]ICRP．1990 Recommendations of the ICRP，ICRP Publication 60[M]．Oxford： Pergamon Press，1991．
[33]ICRP．2007 Recommendations of the ICRP，ICRP Publication 103[M]．Oxford： Pergamon Press，2008．
[34]Hart D，Jones DG，Wall BF．Estimation of effective dose in radiology from entrance surface dose and dose area product measurements[R]．NRPB-262， Chilton：NRPB，1994．
[35]中华人民共和国国家标准．X线诊断中受检者器官剂量的估算方法，GB/T16137-1995[S]．1996．
[36]ICRP．Protection of the Patient in Diagnostic Radiology，ICRP Publication 34[M]．Oxford：Pergamon Press，1982．
[37]Ioppolo JL，Price RI，Tuchyna T，et al．Diagnostic x-ray dosimetry using Monte Carlo simulation[J]．Phys Med Biol，2002，47(10)：1707-1720．
[38]International Atomic Energy Agency．IAEA Technical Reports Series 277， Absorbed dose determination in photon and electron beams[R]．IAEA，Vienna， 1987．
[39]苏森龄．X射线和γ射线防护手册：诊断与科研用[M]．贵阳：贵州人民出版社，1982：27．
[40]李士骏著．电离辐射剂量学[M]．原子能出版社，1986：133．
[41]鱼红亮，孙亮，刘海宽．医用诊断X射线反散射因子的蒙特卡罗方法计算[J]．核技术．2009，已录用．
[42]Briesmeister J F．MCNP-A General Monte Carlo N-particle Transport Code[M] Report LA-12625，Version 4B，Los Almos National Laboratory．1997．
[43]Klevenhagen S C．The build-up of backscatter in the energy range 1 mm Al to 8 mm Al HVL[J]．Phys Med Biol，1982，27：1035-1043．
[44]ICRU．Fundamental quantities and units for ionizing radiation[R]．ICRU Report 60．ICRU Bethesda，MD．USA，1998．
[45]Hubbell JH．Photon mass attenuation and energy absorption coefficients from 1 keV to 20 MeV[J]．Int．J．Appl Radiat Isot．1982，33：1269-1290．
[46]N Petoussi-Henss．Calculation of backscatter factors for diagnostic radiology using Monte Carlo methods[J]．Phys Med Biol，1998，43：2237-2250．
[47]李黎军，宋宏羽，潘洁森，程媛．光子束不规则射野的等效方野计算方法[J]．中华放射医学与防护杂志．2005，25(4)：366-367．
[48]YASUDA H，FUJITAKA K．Solid-state integrating detectors as an indicator of biological doses from HZE particles[J]．Adv Space Res，2002，30(4)：927-932．
[49]Araki F，Moribe N，Shimonobu T，et al．Dosimetric properties of radiophotoluminescent glass rod detector in high-energy photo beams from a liner accelerator and Cyber-Knife[J]．Med Phys，2004，31(7)：1980-1985．
[50]ZHUO W，LIU W，HUANG G，ZHU G，MA G．Comparisons of dosimetric properties between GD-300 series of radiophotoluminescent glass detectors and GR-200 series of thermoluminescent detectors[J]．Nuclear Science and Techniques．2007，18(6)：362-365．
[51]范家栋，谢敬霞．CT诊断学基础(第二版)[M]．北京：北京医科大学出版社，2001：4-5．
[52］辛晓峰，修清玉，施毅，等．高分辨率CT对慢性哮喘患者肺密度CT值测定的定量分析研究[J]．医学研究生学报，2006，19(4)：352-355．
[53]ICRP．Basic anatomical & physiological data for use in radiological protection： the skeleton[M]．ICRP Publication 70．Oxford：Pergamon Press，1996．
[54]ICRP．Managing Patient Dose in Digital Radiology[M]．ICRP Publication 93． Oxford：Pergamon Press，2005．
[55]Peters SE，Brennan PC．Digital radiography：are the manufacturers' settings too high? Optimisation of the Kodak digital radiography system with aid of the computed radiography dose index[J]．Eur Radio]，2002，12(9)：2381-1287．
[56]Warren-Forward H，Arthur L，Hobson L，et al．An assessment of exposure indices in computed radiography for the posterior-anterior chest and the lateral lumbar spine[J]．Br J Radiol，2007，80(949)：26-31
[57]AAPM．Acceptance testing and quality control of photostimulable storage phosphor imaging systemsIR]．AAPM Report No．93．Report of Task Group 10， College Park，MD．USA，2006．
[58]Huda W，Rill LN，Bruner AP．Relative speeds of Kodak computed radiography phosphors and screen-film systems[J]．Med Phys，1997，24：1621-1628．
[59]Willis CE．Strategies for dose reduction in ordinary radiographic examinations using CR and DR[J]．Pediatr Radiol，2004，34：S196-S200．
[60]ICRP．Managing Patient Dose in Computed Tomography[M]．ICRP Publication 87．Oxford：Pergamon Press，2001．
[61]ICRP．Managing Patient Dose in Multi-Detector Computed Tomography (MDCT)[M]．ICRP Publication 102．Oxford：Pergamon Press，2007．
[62]Mettler FA Jr，Thomadsen BR，Bhargavan M，Gilley DB，Gray JE，Lipoti JA， McCrohan J，Yoshizumi TT，Mahesh M．Medical radiation exposure in the U．S．in 2006：preliminary results[J]．Health Phys，2008，95(5)：502-507．
[63]路鹤晴．上海市民1996,1998年X射线诊断照射频率调查[J]．环境与职业医学杂志．2003，20(6)：454-456．
[64]路鹤晴．X射线CT医疗照射剂量水平评价模式与辐射剂量影响因素研究[D]．上海：复旦大学，2008．
[65]Mettler FA Jr，Wiest PW，Locken JA，et al．CT scanning：patterns of use and dose[J]．J Radiol Prot，2000，20(4)：353-359．
[66]Hughes JS，O'Riordon MC．Radiation exposure of the UK population：1993 review[J]．Chilton：National Radiological Protection Board，1993．
[67]Shrimpton PC，Edyvean S．CT scanner dosimetry[J]．Br J Radiol，1998， 71(841)：1-3．
[68]郑钧正．加强医疗照射防护的重点工作［[J]．中华放射医学与防护杂志，2005，25(2)：105-106．
[69]IEC．Evaluation and routine testing in medical imaging departments-Part 3-5： Acceptance tests—imaging performance of computed tomography X-ray equipment．IEC 61223-3-5[S]．2004．
[70]中华人民共和国国家职业卫生标准．X射线计算机断层摄影放射卫生防护标准，GBZ 165-2005[S]．北京：人民卫生出版社，2006．
[71]McNitt-Gray MF．AAPM/RSNA Physics Tutorial for Residents：Topics in CT． Radiation dose in CT[J]．Radiographics，2002，22(6)：1541-1553．
[72]Irwan R，Vries H．de，Sijens P．The Impact of Scan Length on the Exposure Levels in 16-and 64-Row Multidetector Computed Tomography：A Phantom Study[J]．Acad Radiol，2008，15(9)：1142-1147．
[73]DeMarco JJ，Cagnon CH，Cody DD，et al．Estimating radiation doses from multidetector CT using Monte Carlo simulations：effects of different size voxelized patient models on magnitudes of organ and effective dose[J]．Phys Med Biol，2007，52(9)：2583-2597．
[74]Alonso M，Barriuso T，Castaneda，MJ，et al．Monte carlo estimation of absorbed dose to organs in computed tomography[J]．Health Phys，2002，82(2)：233-239．
[75]CEC．Quality criteria for computed tomography，European guidelines．EUR 16262[S]．Luxembourg：Commission of the European Communities，1999．
[76]ZHUO W，LIU W，HUANG G，ZHU G，MA G．Comparisons of dosimetric properties between GD-300 series of radiophotoluminescent glass detectors and GR-200 series of thermoluminescent detectors[J]．Nuclear Science and Techniques．2007，18(6)：362-365．
[77]Pelowitz DB．MCNPX User's Manual，Version 2．5．0[R]．Los Alamos National Laboratory，Report No．LA-UR-02-2607，2005．
[78]石成玉，徐榭，王进亮，白净．新一代虚拟人体解剖模型开发研究及其在放射医学及防护中的应用[J]．中华放射医学与防护杂志，2005，25(2)：201-205．
[79]张居营，徐榭，石成玉．四维动态数字人体模型的开发及其在放疗计划中评估器官呼吸运动影响的研究[J]．中国医学影像技术，2006，22(9)：1301-1305．
[80]Cristy M，Eckerman K．Specific absorbed f ractions of energy at various ages from internal photons sources[R]．Oak Ridge：Oak Ridge National Laboratory，1987．
[81]Williams G，Zankl M，Abmayr W，et al．The calculation of dose from external photon exposures using reference and realistic human phantoms and Monte Carlo methods．Phys Med Biol，1986，31：449-452．
[82]Xu XG，Chao TC，Bozkurt A．VIP-Man：an image-based whole body adult male model constructed from color photographs of the visible human project for multi-particle Monte Carlo calculations[J]．Health Phys，2000，78(5)：476-486．
[83]Zhang JY，Na YH，Xu XG．Development of Whole-Body Phantoms Representing An Average Adult Male and Female Using Surface-Geometry Methods．Med Phys，2008，35(6)：2875．
[84]Zhang J，Na Y，Xu GX．Development of a pair of mesh-based adult male and female computational phantoms and Calculations of organ doses for monoenergetic photon beams．Phys Med Biol．(In press)
[85]ICRP Publication 89：Basic Anatomical and Physiological Data for Use in Radiological Protection: Reference Values[R]. Ann ICRP 2003; 32: 1-277
[86] ICRU Report 46. Photon, electron, proton and neutron interaction data for body tissues[R]. ICRU, Bethesda, MD., USA, 1992.
[87] Gu J, Bednarz B, Caracappa PF, Xu GX. The development, validation and application of a multi-detector CT (MDCT) scanner model for assessing organ doses to the pregnant patient and her fetus using Monte Carlo methods. Phys Med Biol, 2009, 54:2699-2717..
[88] DeMarco JJ, Cagnon CH, Cody DD, Stevens DM, McCollough CH, O'Daniel J and McNitt-Gray MF. A Monte Carlo based method to estimate radiation dose from multidetector CT (MDCT): cylindrical and anthropomorphic phantoms[J].Phys Med Biol, 2005, 50: 3989-4004.
[89] Jarry G, DeMarco JJ, Beifuss U, Cagnon CH and McNitt-Gray MF. A Monte Carlo-based method to estimate radiation dose from spiral CT: from phantom testing to patient-specific models[J]. Phys Med Biol, 2003,48: 2645-2663.
[90] Schlattl H, Zankl M, Petoussi-Henss N. Organ dose conversion coefficients for voxel models of the reference male and female from idealized photon exposures. Phys Med Biol, 2007,52:2123-2145.
[91] King SD, Spiers FW. Photoelectron enhancement of the absorbed dose from X rays to human bone marrow: experimental and theoretical studies. Br J Radiol,1985, 58(688):345-356.
[92] Lee C, Lee C, Shah AP, Bolch WE. An assessment of bone marrow and bone endosteum dosimetry methods for photon sources. Phys Med Biol, 2006,51:5391-5407.
[93] Lewis M A,Edyvean S,Sassi S A,et al.Estimating patient dose on current CT scanners:results of the IMPACT CT dose survey[J].RAD Mag, 2000,8:17-18.