部分地区X射线诊断照射频度调查及CT所致癌症风险的研究
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
研究背景
     随着医用辐射的蓬勃发展和不断普及,在造福人类的同时,也增加了个体和群体的辐射剂量。联合国原子辐射效应科学委员会(UNSCEAR)2008年报告中指出,美国医疗照射所致人均剂量等于或者已经超过天然本底辐射水平,其他国家今后也将出现这种情况,医疗照射正在成为公众最大的电离辐射照射源。我国在1984年与1996年先后组织开展了两次全国性大规模的医疗照射水平调查,为制定防护法规与标准积累了宝贵的数据资料,并且推动了我国医疗照射防护水平的不断提高,但随着放射诊疗设备应用的不断发展和扩大,至今我国仍未有更新的数据。随着X射线诊断照射尤其是CT扫描所占比重的增加,许多国家的调查结果显示一半以上的放射诊断影像的辐射剂量来自CT检查,因此CT扫描可能诱发癌症的风险也引起国际上越来越多的关注与研究,而目前未见针对我国CT扫描可能诱发癌症风险研究的相关报道。
     目的
     1、基于医院信息系统搜集了解不同县级地区X射线诊断照射,尤其是CT扫描的频度及其分布情况,为我国今后医疗照射频度调查提供新思路。
     2、通过估算CT扫描所致患者的器官剂量,利用BEIRⅦ风险预测模型并结合中国的数据估算CT扫描可能诱发癌症的风险,为今后CT扫描在临床应用中的辐射防护提供依据。
     研究方法
     1、选择W、M两个县所有医疗卫生机构(包括县医院(W1与M1)、中医院及乡镇卫生院)与E市两个县区医院(E1与E2),调查其X射线诊断照射的分布情况,及一家儿童医院(M2)调查其CT扫描的分布情况。利用上述医院的信息系统(包括RIS系统、PACS系统及纸质登记本),搜集2012年期间接受X射线诊断照射所有患者的就诊ID、性别、年龄、检查类型、受检部位、检查时间,其中针对CT扫描的受检者相关信息进一步搜集其就诊原因及检查结果(阳性/阴性)。
     2、根据CT扫描的分布,选择W1、E1及E2医院接受头部、胸部CT扫描的患者作为调查对象,通过填写纸质调查表或提取PACS系统内DICOM header头文件内的固定字段获取CT扫描参数,并根据所获取的扫描参数利用CT-Expo软件估算头部及胸部CT扫描所致不同年龄患者不同部位器官剂量。
     3、利用BEIRⅦ癌症风险预测模型并结合中国2008年癌症发病率及人口寿命表估算W1,E1和E2三级医院不同年龄、性别的患者接受单次CT扫描所致不同部位癌症的风险。
     研究结果
     1、本研究涉及7家医院及2个县级地区的乡镇卫生院,共调查2012年期间接受X射线诊断照射653622人次,其中CT扫描为197003人次。2012年W、M两个县CT检查的频次分别为79.65人次/千人口和46.05人次/千人口。不同X射线诊断照射类型中,除X射线诊断摄影以外,CT扫描所占比重较高,分别为26.6%和40.9%,而普通X射线透视检查则十分少见。
     2、对W1、M1、E1三家县医院X射线诊断照射频次分布调查,发现CT扫描在X射线诊断照射的比重分别为:28.3%、41.4%和52.0%。不同CT扫描部位,头部所占比例最高,县级人民医院头部CT比重范围为39.0~66.8%,区医院为33.7%,其中对儿童头部CT扫描的比例高达95%,据调查E2医院51.7%的儿童是由于外伤引起的。对CT扫描阳性率的调查结果显示,头部CT扫描阳性率相对低于其他部位,且年龄越小的患者其阳性率越低。头、胸部接受重复CT扫描的比重较高,并且随患者年龄的增加,CT重复检查的比例也相应增加。
     3、头部CT扫描所致大脑、唾液腺、骨表面和红骨髓的剂量相对较高,而胸部CT扫描所致甲状腺,肺以及胃、肝脏、骨表面和红骨髓器官剂量相对较高。由于不同医院对于相同年龄患者所使用的CT扫描参数不同,因此所致其剂量也不相同,其中头部扫描新生儿可相差5倍(如大脑31.5mSv:5.5mSv),而胸部扫描所致新生儿的器官剂量相差可达11倍(如肺36.6mSv:3.1mSv)。
     4、头部CT扫描所致白血病终生风险男性略高于女性,其范围分别为1.8~11.2/10万人口和1.3-9.4/10万人口,而女性甲状腺癌远高于男性(其风险分别为9.6/10万人口和1.8/10万人口);胸部CT扫描所致女性乳腺癌风险最高,为423.5/10万人口,其次为女性甲状腺癌及肺癌分别为244.7/10万人口和240.9/10万人口,其中肺癌风险约为男性的两倍。此外,胸部扫描所致儿童(女)甲状腺癌的风险最高可达我国基线水平的66%。
     研究结论
     1、利用医院信息系统(RIS/PACS系统)搜集X射线诊断照射资料的方法经济、可行,为我国今后医疗照射频度调查提供了新思路。
     2、不同医院CT扫描所致患者器官剂量差异大,这提示放射科医生及物理师应当根据患者体重和扫描部位适当调整扫描参数,以减少其受照剂量,特别是对儿童受检者。
     3、胸部CT扫描所致患者甲状腺的终生癌症风险较高,因此胸部扫描时,应加强对甲状腺及其它辐射敏感器官的防护。
Background
     As the rapid development and popularity of medical radiation, while it brought huge benefit for the human; it also increased the radiation dose from individual and the collective population. United Nation Scientific Committee on the Effect of Atomic Radiation reported that, medical exposure represented the major source of man-made radiation of the population, even per caput doses from medical exposures was greater than those from the natural background radiation in U.S.; other countries will follow, medical exposures is becoming the biggest radiation source for the public. Our nation conducted two-national wide survey of the frequency of medical exposure in1984and1996, respectively; it provided the valuable data for the development of regulations and standards and also promoted the improvement of the radiation protection from medical exposure in China. With the utilization of radiodiagnosis and radiotherapy devices is continuously developing and expanding, till now no updated data is reported in our nation. The propotion of X-ray diagnositc radiation from medical exposures was increasing, expecially for CT scanning. The surveyed results form many countries showed that half of radiation dose casued by diagnostic radiation imaging was from CT scanning. Therefore the potential radiaiotn cancer risk from CT scanning caused more and more concern around the world, the relative researches about cancer risk induced by CT has not been reported in China.
     Objective
     1. To understand the frequency and distribution of X-ray diagnositc radiation based on the hospital information system, especially for CT scanning, it can provide the new method for the survey of the medical exposure frequency in the future.
     2. To project the potential cancer risk from CT scanning through the calculated organ dose from CT and the BEIRⅦ model combined with Chinese population, it can provide the basis for the radiaiotn protection of the utilization of CT scanning in the clinical in the future.
     Methods
     1. In this study, seven hospitals and township health centers in two county regions were involved, and there were653622people who underwent X-ray diagnostic radiation in2012, among these,197003people were from CT. Through the hospital information system (such as radiology information system, PACS or paper registration) in the above hospitals, to collect the information of patients who underwent X-ray diagnositc radiation in2012, such as patient ID, sex, age, examination type, the exposed body part, examined date. For the patients who exposed CT scanning, the reason and result of examination should also be collected.
     2. According to the distribution of CT scanning, choosing the patients who underwent head or chest CT scanning in W1, E1and E2hospitals as the research object, investigating the parameters of CT scanning through survey tables or abstracting the fixed field in DICOM header from PACS, and then calculating the organ dose for patients with different age and sex by the CT-Expo software.
     3. Based on the cancer risk projection from BEIRⅦ report and combined the Chinese cancer incidence and lifetime table in2008, the cancer risk from a single CT scan for the patients with different age and sex in W1, E1and E2hospitals is calculated.
     Results
     1. The survey investigated the distribution of X-ray diagnositc radiation in all of medical institutions from W and M counties (including the County hospitals (W1and M1), the traditional Chinese medicine hospitals and township hosptials) and in two county-region hospitals (E1and E2), and the distribution of CT scanning in a Children's hospital (M2). The frequency of CT scanning in W and M counties was79.65and46.05per thousand population in2012, respectively. In addition to the X-ray diagnostic radiography, CT scanning accounted for high proportion of the X-ray diagnositc radiation,26.6%and40.9%, respectively, while for the conventional X-ray was very small.
     2. Through the survey of distribution from X-ray diagnositc radiation in W1, M1and E1, it was found that the propotion of CT scannings was28.3%,41.4%and52.0%, repectively. According to the exposed body parts, head CT was higher than others, the range of propotion for head CT in county hospitals was39.0%-66.8%, while for district hospital was33.7%, especially for children that up to95%. There were51.7%of children who underwent CT scanning in E2hospital caused by trauma. The result of positive rate from CT scanning showed that head CT was lower than others and it increased with older patients. The higher propotions of recurrent CT scanning were head and chest, meanwhile, the propotion was also increasing for the older patients.
     3. The relatively higher radiation organ dose for head CT were brain, salivary gland, bone surface and bone marrow; while for chest CT, thyroid, lung, stomach, liver, bone surface and bone marrow have higher radiation dose than other tissues/organs. Due to the different radiation dose caused by the parameters used by CT scanning among different hospitals, there are5-fold diversity of organ dose for the newborn baby who exposed head CT (eg. brain31.5mSv vs5.5mSv); while for chest, there are11-fold difference (eg. lung36.6mSv vs3.1mSv).
     4. The lifetime risk of leukemia for male caused by head CT is higher than that for female, the range of them respectively are1.8-11.2per100thousand population and1.3-9.4per100thousand population; thyroid cancer risk for female was much higher than that for male (the risk is9.6and1.8per100thousand population, respectively). Breast cancer risk for female induced by chest CT is highest,423.5per100thousand population, the next was lung cancer and thyroid cancer which are244.7and240.9per100thousand population, respectively. Among these, lung cancer risk for female is two times higher than that for male. Additionally, the highest potential cancer risk for children from chest CT in this study was approximately66%of the baseline cancer risk in China.
     Conclusion
     1. The method that collecting the data of X-ray diagnostic radiation based on the hospital information system (RIS/PACS) is more economical and feasible; it can provide the new idea for the survey of frequency from national medical exposure in the future.
     2. Due to the huge difference of organ dose induced by CT scanings among different hospitals, it indicated that radiologist and medical physicist should be adjust the parmeters depending on size of patients and the exposed body part, to reduce the radiation dose, especially for children.
     3. The surveyed result showed that the highest lifetime cancer risk of thyroid for chest CT was relatively higher, so more attention should be paid on the radiation protection of thyroid and other radiation-sensitive organs for patients who underwent chest CT scanning.
引文
[1]全国医疗照射研究协作组.我国医疗照射的年频度水平.中华放射医学与防护杂志1989,9:10-16.
    [2]郑均正,岳保荣,李述唐.我国“九五”期间x射线诊断的医疗照射频率水平.中华放射医学与防护杂志2000,5:14-17.
    [3]Brix G, Nissen-Meyer S, Lechel U, et al. Radiation exposures of cancer patients from medical X-rays:how relevant are they for individual patients and population exposure? Eur J Radiol 2009,72:342-347.
    [4]Norelli LJ, Coates AD, Kovasznay BM. Cancer risk from diagnostic radiology in a deliberate self-harm patient. Acta Psychiatr Scand 2010,122:427-430.
    [5]Mettler FA, Jr., Wiest PW, Locken JA, et al. CT scanning:patterns of use and dose. J Radiol Prot 2000,20:353-359.
    [6]ICRP. The 2007 recommendations of the international commission on radiological protection:Elsevier Oxford; 2007.
    [7]United Nations Scientific Committee on the Effects of Atomic Radiation. Sources and effects of ionizing radiation medical radiation exposures, annexe D. New York: United Nations; 2000.
    [8], National Research Council (US). Committee to assess health risks from exposure to low levels of ionizing radiation. Health risks from exposure to low levels of ionizing radiation:BEIR Ⅶ-Phase 2:Washington, DC:National Academies Press; 2006.
    [9]Huang WY, Muo CH, Lin CY, et al. Paediatric head CT scan and subsequent risk of malignancy and benign brain tumour:a nation-wide population-based cohort study. BrJ Cancer 2014.
    [10]Mathews JD, Forsythe AV, Brady Z, et al. Cancer risk in 680,000 people exposed to computed tomography scans in childhood or adolescence:data linkage study of 11 million Australians. BMJ 2013,346:f2360.
    [11]Pearce MS, Salotti JA, Little MP, et al. Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours:a retrospective cohort study. Lancet 2012,380:499-505.
    [12]陶祖范.医用辐射照射所致癌症危险.中国医学装备2005,2:32-34.
    [13]刘长安,苏旭,孙全富.放射工作人员职业健康监护:原子能出版社;2004.
    [14]United Nations Scientific Committee on the Effects of Atomic Radiation. Sources and effects of ionizing radiation medical radiation exposures, annexe A. New York: United Nations; 2010.
    [15]范瑶华,岳保荣,刘澜涛.医学放射设备现状及分析.中国医学装备2005,2:51-53.
    [16]张伟军,曹吉生,袁龙,等.全国放射诊疗设备资源现状和分析.中华放射医学与防护杂志2012,32(1):87-89.
    [17]Berrington de Gonzalez A, Darby S. Risk of cancer from diagnostic X-rays: estimates for the UK and 14 other countries. Lancet 2004,363:345-351.
    [18]Berrington de Gonzalez A, Mahesh M, Kim KP, et al. Projected cancer risks from computed tomographic scans performed in the United States in 2007. Arch Intern Med 2009,169:2071-2077.
    [19]Brenner DJ, Elliston CD, Hall EJ, et al. Estimated risks of radiation-induced fatal cancer from pediatric CT. American journal of roentgenology 2001,176:289-296.
    [20]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.中华放射医学与防护杂志2001,20:14-18.
    [21]高林峰,郭常义,郑钧正,等.上海市“十一五”期间医疗照射水平调查.环境与职业医学2009,26:528-531.
    [22]杨宇华,曾锡慎,吴增汉,等.广东省医疗照射频率与剂量水平调查研究.中国辐射卫生2004,13:65-68.
    [23]Chen TR, Tyan YS, Teng PS, et al. Population dose from medical exposure in Taiwan for 2008. Med Phys 2011,38:3139-3148.
    [24]Zondervan RL, Hahn PF, Sadow CA, et al. Frequent body CT scanning of young adults:indications, outcomes, and risk for radiation-induced cancer. J Am Coll Radiol 2011,8:501-507.
    [25]Sodickson A, Baeyens PF, Andriole KP, et al. Recurrent CT, cumulative radiation exposure, and associated radiation-induced cancer risks from CT of adults. Radiology 2009,251:175-184.
    [26]Hart D, Wall BF. UK population dose from medical X-ray examinations. Eur J Radiol 2004,50:285-291.
    [27]Scanff P, Donadieu J, Pirard P, et al. Population exposure to ionizing radiation from medical examinations in France. Br J Radiol 2008,81:204-213.
    [28]Krille L, Zeeb H, Jahnen A, et al. Computed tomographies and cancer risk in children:a literature overview of CT practices, risk estimations and an epidemiologic cohort study proposal. Radiat Environ Biophys 2012,51:103-111.
    [29]王徐冬,杨希武.我国HIS的发展及未来趋势.医疗卫生装备2008,29:39-41.
    [30]罗敏,彭承琳,罗松,等.医院RIS系统的应用.医疗设备信息2006,21:13-15.
    [31]吴静炯,罗晓晨,唐苏红.区域医疗与PACS网络系统建设的决策意义.中国医疗器械信息2013,19:14-16.
    [32]2011年中国PACS发展研究报告(摘要版).中国信息界(e医疗)2012:20-24.
    [33]何俊诗,梁鹏,史瑞雪,等.区域PACS系统医学影像智能专家库设计与实现分析.临床医学工程2012,19:669-671.
    [34]钱凯.PACS系统的现状与发展.医疗装备2011,24:23-24.
    [35]蒋建荣,张建国.HIS/RIS与PACS及其集成关系.红外2002:15-18.
    [36]National Electrical Manufactures Associaton. Digital Imaging and Communications in Medicine(DICOM). In. Rosslyn, Virginia 22209 USA.http://medical.nema.org/;2009.
    [37]DCMTK-DICOM Toolkit, http://www.dcmtk.org/dcmtk.php.en
    [38]卫生部,卫生监督司.放射诊疗管理规定:人民卫生出版社;2006.
    [39]张裔智,赵毅,汤小斌.MD5算法研究.计算机科学2008,35:295-297.
    [40]Zondervan R, Hahn P, Sadow C, et al. Risks of Body CT Scanning in Young Adults. Radiology 2013,267:460-469.
    [41]王彬,郑钧正,高林峰,等.上海市医用X射线CT的应用频率及其分布研究.辐射防护2013,33:65-73.
    [42]King MA, Kanal KM, Relyea-Chew A, et al. Radiation exposure from pediatric head CT:a bi-institutional study. Pediatr Radiol 2009,39:1059-1065.
    [43]陈俊波,顾钱峰,胡开艳.区域性医学影像归档与传输系统(PACS)的应用初探.浙江医学教育2010,3:009.
    [44]Mettler FA, Jr., Thomadsen BR, Bhargavan M, et al. Medical radiation exposure in the U.S. in 2006:preliminary results. Health Phys 2008,95:502-507.
    [45]Nishizawa K, Iwata T, Furuya Y, et al. [Estimation of stochastic risk from computed tomography examinations in Japan,1979.1. The number of examinations and scans (author's transl)]. Nihon Igaku Hoshasen Gakkai Zasshi 1981,41:45-49.
    [46]Nishizawa K, Maruyama T, Takayama M, et al. [Estimation of effective dose from CT examination]. Nihon Igaku Hoshasen Gakkai Zasshi 1995,55:763-768.
    [47]Nishizawa K, Matsumoto M, Iwai K, et al. [Survey of CT practice in Japan and collective effective dose estimation]. Nihon Igaku Hoshasen Gakkai Zasshi 2004,64:151-158.
    [48]路鹤晴,卓维海,高林峰,等.上海市“十五”和“十一五”期间X射线CT医疗照射水平调查.中国辐射卫生2010,19:129-131.
    [49]Ghotbi N, Ohtsuru A, Ogawa Y, et al. Pediatric CT scan usage in Japan:results of a hospital survey. Radiat Med 2006,24:560-567.
    [50]Verdun FR, Gutierrez D, Vader JP, et al. CT radiation dose in children:a survey to establish age-based diagnostic reference levels in Switzerland. Eur Radiol 2008,18:1980-1986.
    [51]Brenner DJ, Hall EJ. Computed tomography--an increasing source of radiation exposure. N Engl J Med 2007,357:2277-2284.
    [52]邓大平,王燕南,孙秀兰,等.X射线CT检查阳性检出率调查及其合理应用.中华放射医学与防护杂志1995,15:272-273.
    [53]杨望平,蔡雪娟,张浩.X射线CT检查阳性检出率调查分析.中华放射医学与防护杂志2001,21:243.
    [54]Dorfman AL, Fazel R, Einstein AJ, et al. Use of medical imaging procedures with ionizing radiation in children:a population-based study. Archives of pediatrics& adolescent medicine 2011,165:458-464.
    [55]Hansen J, Jurik AG. Analysis of Current Practice of CT examinations. Acta Oncol 2009,48:295-301.
    [56]Kaups KL, Davis JW, Parks SN. Routinely repeated computed tomography after blunt head trauma:does it benefit patients? J Trauma 2004,56:475-480; discussion 480-471.
    [57]Renton J, Kincaid S, Ehrlich P. Should helical CT scanning of the thoracic cavity replace the conventional chest x-ray as a primary assessment tool in pediatric trauma? An efficacy and cost analysis. Journal of pediatric surgery 2003,38:793-797.
    [58]Maytal J, Krauss JM, Novak G, et al. The role of brain computed tomography in evaluating children with new onset of seizures in the emergency department. Epilepsia 2000,41:950-954.
    [59]Lewis DW, Dorbad D. The utility of neuroimaging in the evaluation of children with migraine or chronic daily headache who have normal neurological examinations. Headache:The Journal of Head and Face Pain 2000,40:629-632.
    [60]Stephen AE, Segev DL, Ryan DP, et al. The diagnosis of acute appendicitis in a pediatric population:to CT or not to CT. Journal of pediatric surgery 2003,38:367-371.
    [61]Krille L, Scholz P, Miritz G, et al. KiCT:Cancer risk after exposure with computed tomographies in childhood:descriptive analysis of the feasibility study.
    [62]Hsieh J,朝宗.计算机断层成像技术:原理,设计,伪像和进展:科学出版社;2006.
    [63JGBZ165-2005. X射线计算机断层摄影放射卫生防护标准[S];2005.
    [64]Commission IE. Evaluation and routine testing in medical imaging departments. Part 3-5:Acceptance tests-Imaging performance of computed tomography X-ray equipment. IEC Publication 2004:61223-61223.
    [65]ICRP. Managing Patient Dose in Computed Tomography. In:ICRP Publication 87; 2001.
    [66]McNitt-Gray MF. AAPM/RSNA Physics Tutorial for Residents:Topics in CT Radiation Dose in CT1. Radiographics 2002,22:1541-1553.
    [67]Irwan R, de Vries HB, Sijens PE. The impact of scan length on the exposure levels in 16-and 64-row multidetector computed tomography:a phantom study. Acad Radiol 2008,15:1142-1147.
    [68]李辉,季成叶,宗心南,等.中国0~18岁儿童,青少年身高,体重的标准化生长曲线.中华儿科杂志2009,47:487-492.
    [69]Zankl M. The calculation of dose from external photon exposures using reference human phantoms and Monte Carlo methods:GSF-Forschungszentrum fur Umwelt und Gesundheit; 1991.
    [70]刘海宽.X射线诊断所致受检者剂量的估算模式研究.上海:复旦大学2009.
    [71]Lee C, Kim KP, Long DJ, et al. Organ doses for reference pediatric and adolescent patients undergoing computed tomography estimated by Monte Carlo simulation. Med Phys 2012,39:2129-2146.
    [72]Kalender WA, Schmidt B, Zankl M, et al. A PC program for estimating organ dose and effective dose values in computed tomography. Eur Radiol 1999,9:555-562.
    [73]Abdullah A, Sun Z, Pongnapang N, et al. Comparison of computed tomography dose reporting software. Radiat Prot Dosimetry 2012,151:153-157.
    [74]Brady Z, Cain TM, Johnston PN. Comparison of organ dosimetry methods and effective dose calculation methods for paediatric CT. Australas Phys Eng Sci Med 2012,35:117-134.
    [75]Linet MS, Kim KP, Rajaraman P. Children's exposure to diagnostic medical radiation and cancer risk:epidemiologic and dosimetric considerations. Pediatr Radiol 2009,39 Supp11:S4-26.
    [76]Feng ST, Law MW, Huang B, et al. Radiation dose and cancer risk from pediatric CT examinations on 64-slice CT:a phantom study. Eur J Radiol 2010,76:e19-23.
    [77]Nishizawa K, Mori S, Ohno M, et al. Patient dose estimation for multi-detector-row CT examinations. Radiat Prot Dosimetry 2008,128:98-105.
    [78]Paterson A, Frush DP, Donnelly LF. Helical CT of the body:are settings adjusted for pediatric patients? AJR Am J Roentgenol 2001,176:297-301.
    [79]Huda W, Ogden KM. Computing effective doses to pediatric patients undergoing body CT examinations. Pediatr Radiol 2008,38:415-423.
    [80]Arthurs OJ, Yates SJ, Set PA, et al. Evaluation of image quality and radiation dose in adolescent thoracic imaging:64-slice is preferable to 16-slice multislice CT. Br J Radiol 2009,82:157-161.
    [81]Huda W, Scalzetti EM, Roskopf M. Effective doses to patients undergoing thoracic computed tomography examinations. Med Phys 2000,27:838-844.
    [82]Tzedakis A, Damilakis J, Perisinakis K, et al. The effect of z overscanning on patient effective dose from multidetector helical computed tomography examinations. Med Phys 2005,32:1621-1629.
    [83]Huda W, Spampinato MV, Tipnis SV, et al. Computation of thyroid doses and carcinogenic radiation risks to patients undergoing neck CT examinations. Radiat Prot Dosimetry 2013,156:436-444.
    [84]Thomton FJ, Paulson EK, Yoshizumi TT, et al. Single versus multi-detector row CT:comparison of radiation doses and dose profiles. Acad Radiol 2003,10:379-385.
    [85]Brix G, Nagel HD, Stamm G, et al. Radiation exposure in multi-slice versus single-slice spiral CT:results of a nationwide survey. Eur Radiol 2003,13:1979-1991.
    [86]Yates S, Pike L, Goldstone K. Effect of multislice scanners on patient dose from routine CT examinations in East Anglia. British journal of radiology 2004,77:472-478.
    [87]Dawson P. Patient dose in multislice CT:why is it increasing and does it matter. Br J Radiol 2004,77:S10-S13.
    [88]Shrimpton P, Britain G. Doses from computed tomography (CT) examinations in the UK-2003 review:National Radiological Protection Board Chilton, UK; 2005.
    [89]Shrimpton P, Jones D, Hillier M, et al. Survey of CT practice in the UK Part 2: Dosimetric aspects:National Radiological Protection Board Chilton, UK; 1991.
    [90]孟悛非,范淼.重视CT低剂量研究.中华放射学杂志2009,43:679-680.
    [91]Lee CI, Haims AH, Monico EP, et al. Diagnostic CT scans:assessment of patient, physician, and radiologist awareness of radiation dose and possible risks. Radiology 2004,231:393-398.
    [92]Linton OW, Mettler FA, Jr. National conference on dose reduction in CT, with an emphasis on pediatric patients. AJR Am J Roentgenol 2003,181:321-329.
    [93]ICRP. Managing patient dose in multi-detector computed tomography(MDCT). ICRP Publication 102. Ann ICRP 2007,37:1-79, iii.
    [94]Preston DL, Mattsson A, Holmberg E, et al. Radiation effects on breast cancer risk:a pooled analysis of eight cohorts. Radiat Res 2002,158:220-235.
    [95]Ron E, Lubin JH, Shore RE, et al. Thyroid cancer after exposure to external radiation:a pooled analysis of seven studies. Radiat Res 1995,141:259-277.
    [96]国家癌症中心,卫生部疾病预防控制局.中国肿瘤登记年报,2008:军事医学科学出版社;2011.
    [97]国家统计局人口和就业统计司.中国人口和就业统计年鉴:中国统计出版社;2010.
    [98]李小亮,牛吴巍,孙全富.我国辐射相关癌症终生危险基线值估计.中华放射医学与防护杂志2011,6:695-697.
    [99]Huang B, Law MW, Mak HK, et al. Pediatric 64-MDCT coronary angiography with ECG-modulated tube current:radiation dose and cancer risk. AJR Am J Roentgenol 2009,193:539-544.
    [100]Smith-Bindman R, Lipson J, Marcus R, et al. Radiation dose associated with common computed tomography examinations and the associated lifetime attributable risk of cancer. Archives of Internal Medicine 2009,169:2078-2086.
    [101]Huda W, Schoepf UJ, Abro JA, et al. Radiation-related cancer risks in a clinical patient population undergoing cardiac CT. American journal of roentgenology 2011,196:W159-W165.
    [102]Walsh L, Shore R, Auvinen A, et al. Risks from CT scans-what do recent studies tell us? Journal of Radiological Protection 2014,34:E1.
    [103]ICRP (International Commission on Radiological Protection). ICRP Publication 60:1990 Recommendations of the ICRP. Oxford, UK:Pergamon, Elsevier Science; 1991.
    [104]NCRP(National Council on Radiation Protection and Measurements)..Limitating of Exposure to Ionizing Radiation, NCRP Report No. 116.. Bethesda, MD; 1993.
    [105]EPA(Environmental Protection Agency). Estimating Radiogenic Cancer Risk. Addendum:Uncertainty Analysis. Washington DC:U.S. Environmental Protection Agency; 1999.
    [106]UNSCEAR(United Nations Scientific Committee on the Effects of Atomic Radiation). UNSCEAR Report to the General Assembly, Volume II:Effect. In:Source and Effects of Ionizing Radiation. New York:United Nations; 2000.
    [107]ICRP (International Commission on Radiological Protection). ICRP Publication 92:Relative biological effectiveness(RBE), quality facotr(QF), and radiation weighting factor(WR). A reported of the International Commission on Radiological Protection. In; 2003. pp. Ann ICRP 33:31-177.
    [108]Environmental Protection Agency. EPA Radiogenic Cancer Risk Models and Projections for the U.S. Population. Washington, DC:U.S. Environmental Protection Agency; 2011.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700