中国人仿真胸部体模检测多层螺旋CT扫描患者器官剂量的实验研究
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摘要
目的:通过实验对中国人仿真胸部体模从CT断层解剖和组织X线衰减等效性两方面与正常成人作对比研究,评价其临床和科研价值。
方法:选取正常成年男性自愿者(门诊健康体检人员,年龄20～50岁,身高165～170 cm,体重60 kg左右)10人作为对照。使用GE公司Brightspeed Elite 16排螺旋CT以相同的技术参数分别对CDP-1C型中国人仿真胸部体模和正常成人行常规胸部CT扫描,根据CT横断面图像所反映的解剖结构判断两者的相似程度;根据对各组织器官CT值测量后分析体模组织的X线衰减等效程度。
结果:在CT断层解剖方面,中国人仿真胸部体模与正常成人基本相似;在组织X线衰减等效性方面,体模与人体肺、心脏、脊柱CT值比较,差异无统计学意义(P >0.05),体模肝脏与人体肝脏偏差程度最大,为4.49%。体模的组织器官CT值与人体组织器官偏差程度均小于5%,符合实验型体模标准。
结论:中国人仿真胸部体模作为客观的评价工具,可以应用于CT低剂量技术的实验研究。
第二部分多层螺旋CT扫描患者器官剂量的实验研究
目的:利用中国人仿真胸部模型来测量不同噪声指数下胸部各组织器官的吸收剂量,计算有效剂量(ED)并对MSCT胸部扫描进行剂量评估。
方法:通过在体模内布放热释光剂量计(TLD)来测量不同噪声水平下各组织器官的吸收剂量,并记录相应的平均剂量长度乘积(DLP);将两者分别换算为ED后进行对比研究,分析自动管电流调制(ATCM)技术时不同噪声指数胸部CT扫描的剂量水平。统计学方法选择单因素t检验,采用SPSS 12.0统计软件进行分析。
结果:当噪声指数从8.5逐渐增至22.5时,DLP均值从393.57mGy/cm递减至78.75mGy/cm,各器官吸收剂量呈下降趋势(以肺为例,平均吸收剂量从22.38 mGy递减至3.66mGy)。应用DLP均值所计算的ED较器官吸收剂量计算的ED偏低(以噪声指数为8.5为例,两种方法的ED分别为6.69和8.77 mSv)。
结论:应用中国人仿真体模来进行CT剂量评估更为准确;基于ATCM技术的胸部CT扫描噪声指数设定至少应大于8.5。
Objective: To evaluate the clinical and research value of anthropomorphic chest phantom from CT sectional anatomy and tissue equivalence of X-ray attenuation by comparing with normal adults.
Methods: Ten clinically healthy male volunteers, aged 20 to 50 years old, with an average height of 165 ~ 170 cm, and weight of 60 kg served as a control group. The GE Bright speed Elite 16-slice spiral CT scanner served as the choice for the study. The Chinese anthropomorphic chest phantom(CDP-1C) and the normal adults were scanned with the same scanning parameters, according to the Sectional image and the CT value of the various tissues and organs to evaluate the Similarity of Anatomy and the tissue equivalence of X-ray attenuation respectively.
Results: On anatomic morphology, the Chinese anthropomorphic chest phantom was basically similar to the normal adult; on tissue equivalence of X-ray attenuation , no significant difference of CT value were shown between the lung,heart and spine of phantom and human(P >0.05). The maximum deviation on the liver was 4.49%. The CT value error of each tissue and organ was less than 5% between phantom and human, which is reaching the standard of experiment.
Conclusion: The Chinese anthropomorphic chest phantom can be used to study of low-dose CT based on objective evaluation criteria.
PART2 THE MEASUREMENT OF ORGANIC RADIATION DOSE WITH MULTI-SLICE CT BY USING THE CHINESE ANTHROPOMORPHIC CHEST PHANTOM
Objective: Using the Chinese anthropomorphic chest phantom to measure absorbed dose of various tissues and organs under different noise index, calculation of the effective dose(ED) was used to evaluate the chest scanning with MSCT.
Methods: To measure absorbed dose of various tissues and organs under different noise index by laying thermoluminescent dosimeters(TLD) inside the phantom, and the corresponding dose-length product(DLP) was recorded. Both of them were later converted into ED and comparative studies to analyze dose levels of chest CT scanning with automatic tube current modulation(ATCM) under different noise index.Statistical analysis is slected t test of single factor, using SPSS12.0 statistical software to analyze.
Results: As the noise index increase from 8.5 to 22.5,The DLP decrease from 393.57mGy/cm to 78.75mGy/cm and the organs dose decline,for example,the average absorbed dose decrease from 22.38 mGy to 3.66mGy in lung. Compared with ED calculating by absorbed dose, The ED calculating by DLP was lower,and the ED are 6.69 mSv and 8.77 mSv respectly when the noise index is set 8.5.
Conclusion: Application of the Chinese anthropomorphic chest phantom to carry out CT dose assessment is more accurate. The noise index should be set larger than 8.5 during the chest CT screening based on ATCM technique.
方法:选取正常成年男性自愿者(门诊健康体检人员,年龄20～50岁,身高165～170 cm,体重60 kg左右)10人作为对照。使用GE公司Brightspeed Elite 16排螺旋CT以相同的技术参数分别对CDP-1C型中国人仿真胸部体模和正常成人行常规胸部CT扫描,根据CT横断面图像所反映的解剖结构判断两者的相似程度;根据对各组织器官CT值测量后分析体模组织的X线衰减等效程度。
结果:在CT断层解剖方面,中国人仿真胸部体模与正常成人基本相似;在组织X线衰减等效性方面,体模与人体肺、心脏、脊柱CT值比较,差异无统计学意义(P >0.05),体模肝脏与人体肝脏偏差程度最大,为4.49%。体模的组织器官CT值与人体组织器官偏差程度均小于5%,符合实验型体模标准。
结论:中国人仿真胸部体模作为客观的评价工具,可以应用于CT低剂量技术的实验研究。
第二部分多层螺旋CT扫描患者器官剂量的实验研究
目的:利用中国人仿真胸部模型来测量不同噪声指数下胸部各组织器官的吸收剂量,计算有效剂量(ED)并对MSCT胸部扫描进行剂量评估。
方法:通过在体模内布放热释光剂量计(TLD)来测量不同噪声水平下各组织器官的吸收剂量,并记录相应的平均剂量长度乘积(DLP);将两者分别换算为ED后进行对比研究,分析自动管电流调制(ATCM)技术时不同噪声指数胸部CT扫描的剂量水平。统计学方法选择单因素t检验,采用SPSS 12.0统计软件进行分析。
结果:当噪声指数从8.5逐渐增至22.5时,DLP均值从393.57mGy/cm递减至78.75mGy/cm,各器官吸收剂量呈下降趋势(以肺为例,平均吸收剂量从22.38 mGy递减至3.66mGy)。应用DLP均值所计算的ED较器官吸收剂量计算的ED偏低(以噪声指数为8.5为例,两种方法的ED分别为6.69和8.77 mSv)。
结论:应用中国人仿真体模来进行CT剂量评估更为准确;基于ATCM技术的胸部CT扫描噪声指数设定至少应大于8.5。
Objective: To evaluate the clinical and research value of anthropomorphic chest phantom from CT sectional anatomy and tissue equivalence of X-ray attenuation by comparing with normal adults.
Methods: Ten clinically healthy male volunteers, aged 20 to 50 years old, with an average height of 165 ~ 170 cm, and weight of 60 kg served as a control group. The GE Bright speed Elite 16-slice spiral CT scanner served as the choice for the study. The Chinese anthropomorphic chest phantom(CDP-1C) and the normal adults were scanned with the same scanning parameters, according to the Sectional image and the CT value of the various tissues and organs to evaluate the Similarity of Anatomy and the tissue equivalence of X-ray attenuation respectively.
Results: On anatomic morphology, the Chinese anthropomorphic chest phantom was basically similar to the normal adult; on tissue equivalence of X-ray attenuation , no significant difference of CT value were shown between the lung,heart and spine of phantom and human(P >0.05). The maximum deviation on the liver was 4.49%. The CT value error of each tissue and organ was less than 5% between phantom and human, which is reaching the standard of experiment.
Conclusion: The Chinese anthropomorphic chest phantom can be used to study of low-dose CT based on objective evaluation criteria.
PART2 THE MEASUREMENT OF ORGANIC RADIATION DOSE WITH MULTI-SLICE CT BY USING THE CHINESE ANTHROPOMORPHIC CHEST PHANTOM
Objective: Using the Chinese anthropomorphic chest phantom to measure absorbed dose of various tissues and organs under different noise index, calculation of the effective dose(ED) was used to evaluate the chest scanning with MSCT.
Methods: To measure absorbed dose of various tissues and organs under different noise index by laying thermoluminescent dosimeters(TLD) inside the phantom, and the corresponding dose-length product(DLP) was recorded. Both of them were later converted into ED and comparative studies to analyze dose levels of chest CT scanning with automatic tube current modulation(ATCM) under different noise index.Statistical analysis is slected t test of single factor, using SPSS12.0 statistical software to analyze.
Results: As the noise index increase from 8.5 to 22.5,The DLP decrease from 393.57mGy/cm to 78.75mGy/cm and the organs dose decline,for example,the average absorbed dose decrease from 22.38 mGy to 3.66mGy in lung. Compared with ED calculating by absorbed dose, The ED calculating by DLP was lower,and the ED are 6.69 mSv and 8.77 mSv respectly when the noise index is set 8.5.
Conclusion: Application of the Chinese anthropomorphic chest phantom to carry out CT dose assessment is more accurate. The noise index should be set larger than 8.5 during the chest CT screening based on ATCM technique.
引文
[1] Nevzat K,Macit A. Low-dose CT:practices and strategies of radiologists in university hospitals[J].Diagn Interv Radiol.2006,12(1):3-8.
[2] Maher MM., Kalra MK, Toth TL, et al.Application of rational practice and technicaladvances for optimizing radiation dose for chest CT[J]. J Thorac Imaging.2004,19(1):16-23.
[3] Mayo JR,Aldrich J,Muller NL,et al.Radiation exposure at chest CT: a statement of the Fleischner Society[J]. Radiology.2003,228(1):15-21.
[4] Mettler FJ,Wiest PW,Locken JA,et al. CT scanning: patterns of use and dose[J]. J Radiol Prot.2000,20(4):3533-3559.
[5] Diederich S , Lenzen H , Wormanns W, et al . Pulmonary nodules experimental and clinical studies at low-dose CT[J].Radiology.1999;213(1):289-298.
[6] Shrimpton P C, Edyvean S. CT scanner dosimetry[J].Br J Radiol, 1998; 71(841): 1-3.
[7]张春红,林大全.探析我国仿真人体模型中的仿生技术[J].机械.2009,36(1):1-2.
[8]张春红,林大全.中国成人仿真人体模型的参数研究[J].机械.2009,36(7):1-3.
[1] Yoshihisa M, Yukihiro T, Yoshimasa N, et al.The Development and Use of a Chest Phantom for Optimizing Scanning Techniques on a Variety of Low-Dose Helical Computed Tomography Devices[J]. Journal of Computer Assisted Tomography.2003,27(3):364–374.
[2] Nevzat K,Macit A.Low-dose CT:practices and strategies of radiologists in university hospitals[J].Diagn Interv Radiol .2006,12(1):3-8.
[3] Nickoloff EL,Alderson PO.Radiation exposures to patients form CT:reality ,public perception and policy[J]. AJR.2001,177(1):285 - 287.
[4] Maher MM, Kalra MK, Toth TL, et al. Application of rational practice and technical advances for optimizing radiation dose for chest CT[J]. J Thorac Imaging .2004, 19(1):16-23.
[5] Hart D, Wall BF. UK population dose from medical X-ray examinations[J]. Eur J Radiol.2004, 50(3):285–291.
[6] Xiaohua Zhu,Jianqun Yu,Zheng Huang. Low-Dose Chest CT: Optimizing Radiation Protection for Patients[J]. AJR.2004,183(3):809-816.
[7] Yoshiharu O,Hisanobu K,Astushi K,et al. Influence of detector collimation and beam pitch for identification and image quality of ground-glass attenuation and nodules on 16-and 64-detector row CT systems:Experimental study using chest phantom[J].Eur J Radiology.2007,64(3):406-413.
[8] John D,Kostas P,Panos P,et al.Conceptus radiation dose and risk from chest screen-film radiography[J]. Eur Radiol.2003,13(3):406-412.
[9]曾勇明.数字X线成像技术操作规范与剂量优化[M].重庆:重庆出版社.2009,117-118.
[10]张春红,林大全.中国成人仿真人体模型的参数研究[J].机械.2009,36(7):1-3.
[11]张春红,林大全.探析我国仿真人体模型中的仿生技术[J].机械.2009,36(1):1-2.
[12]曾勇明,张志伟,梁开运,等.双能量减影胸部成像模拟肺部病变检出的实验研究[J].重庆医科大学学报.2007,32(7):686-688.
[13]曾勇明,吴富荣,张志伟,等.数字X线摄影辐射剂量与图像质量相关性的实验研究[J].重庆医科大学学报.2009,34(11):1517-1520.
[1] Nevzat K,Macit A.Low-dose CT:practices and strategies of radiologists in university hospitals[J].Diagn Interv Radiol.2006,12(1):3-8.
[2] Maher MM, Kalra MK, Toth TL,et al. Application of rational practice and technical advances for optimizing radiation dose for chest CT[J]. J Thorac Imaging.2004,19(1):16-23.
[3] Mayo JR, Aldrich J, Muller NL,et al. Radiation exposure at chest CT: a statement of the Fleischner Society[J]. Radiology.2003,228(1):15-21.
[4] Mettler FA Jr, Wiest PW, Locken JA, Kelsey CA. CT scanning: patterns of use and dose[J]. J Radiol Prot.2000,20(4):3533-3559.
[5] ICRP.Managing patient dose in multi-detector computed tomography(MSCT).ICRP Publication 102.Oxford:Pergamon press,2007.
[6] ICRP.The 2007 recommendations of the International Commission on Radiological Protection 103.Oxford:Pergamon Press,2008.
[7] CEC.Quality criteria for computed tomography,European guidelines[M].EUR 16262.Luxembourg:Commission of the European Communities,1999.
[8] Nevzat K,Macit A.Low-dose CT:practices and strategies of radiologists in university hospitals[J].Diagn Interv Radiol .2006,12(1):3-8.
[9] Nickoloff EL , Alderson PO. Radiation exposures to patients form CT:reality ,public perception and policy[J]. AJR.2001,177(1):285-287.
[10]Maher MM, Kalra MK, Toth TL,et al. Application of rational practice and technical advances for optimizing radiation dose for chest CT[J]. J Thorac Imaging .2004, 19(1):16-23.
[11]Hart D, Wall BF. UK population dose from medical X-ray examinations[J]. Eur J Radiol.2004, 50(3):285-291.
[12]白玫,刘彬,郑钧正,等.两种介入放射学(CT和PTCA)所致患者辐射剂量研究[J].中国医学影像技术.2007,23(12):1876-1881.
[13]张春红,林大全.探析我国仿真人体模型中的仿生技术[J].机械.2009,36(1):1-2.
[14]张春红,林大全.中国成人仿真人体模型的参数研究[J].机械.2009,36(7):1-3.
[15]Lloyd DC,Edwards AA,Leonard A,et al.Chromosomal aberrations in human lymphocytes induced in vitro by very low doses of X-rays[J].Int J Radiat Biol.1992,61(3):335-343.
[1] Nevzat K,Macit A.Low-dose CT:practices and strategies of radiologists in university hospitals[J].Diagn Interv Radiol. 2006,12(1):3-8.
[2] Nickoloff EL , Alderson PO. Radiation exposures to patients from CT:reality ,public perception and policy[J] . AJR.2001,177(2):285-287.
[3] Shrimpton P C, Edyvean S. CT scanner dosimetry[J].Br J Radiol.1998,71(841): 1-3.
[4]郑钧正,贺青华,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.2000,20 (增刊) : s7.
[5] Diederich S , Lenzen H , Wormanns W, et al . Pulmonary nodules experimental and clinical studies at low-dose CT[J].Radiology.1999,213(1):289-298.
[6] Naidich DP, Marshall CH, Gribbin C, et al. Low - dose CT of the lungs: preliminary observation [ J ]. Radiology.1990,175 ( 3 ) : 729 -731.
[7]殷少龙,赵春龙,于文东,等.低剂量螺旋CT扫描在肺部空洞性病变诊断中的价值[J].实用预防医学.2008,15(3):851.
[8] Yoshiharu O,Hisanobu K,Astushi K,et al. Influence of detector collimation and beam pitch for identification and image quality of ground-glass attenuation and nodules on 16-and 64-detector row CT systems:Experimental study using chest phantom[J].Eur J Radiology.2007,64(2):406-413.
[9] Mahesh M, Scatarige J C, Cooper J, et al. Dose and pitch relationship for a particular multislice CT scanner[J]. Am J Roentgenol.2001,177(6): 1273-1275.
[10]周泽俊,胡永胜.多层螺旋CT螺距,层厚和重建间隔关系对图像质量影响[J].CT理论与应用研究.2008,17(1):21-26.
[11]路鹤晴,朱国英,卓维海,等.医用X射线CT辐射剂量影响因素研究[J].上海医学影像.2008,17(2):93-96.
[12]Hidajt N,Maurer J,Schroder RJ,et al.Relationship between physical dose quantities and patient dose in CT[J].Bri J Radiol.1999,72:556-561.
[13]Mannudeep K,Michael M,Thomas L,et al.Techniques and applications of automatic tube current modulation for CT[J].Radiology.2004,233(12):649-657.
[14]Hidajat N, Maurer J, et al. Relationships between physical dose quantities and patient dose in CT[J]. Br J Radiol.1999,72(858):556-561.
[15]贾明轩,张煊,刘为,等.CT检查所致病人剂量的简便估算方法[J].中华放射医学与防护杂志.2001,21(5):374-376.
[16]Rusinek H,Naidich D,et al.Pulmonary nodule detection:low-dose versus conventional CT[J].Radiology.1998,209(1):243-249.
[17]Nitta N,Takahashi M,Murata K,et al.Ultra low-dose helical CT of the chest[J].AJR.1998,171(2):383-385.
[18]朱天照,蒋学祥,唐光键.螺旋CT肺结节检出率的实验研究[J].中国医学影像技术.2003,19(7):833-835.
[19]Itoh S,Ikeda M,Arahata S,et al. Lung cancer screening: minimum tube current required for helical CT[J]. Radiology.2000,215(1):175-183.
[20]Kaneko M, Kusumoto M, Kobayashi T, et al. Computed tomography screening for lung carcinoma in Japan[J]. Cancer .2000,89 (Suppl) : 2485 - 2488.
[21]Yoshihisa Muramatsu, Yukihiro Tsuda, Yoshimasa Nakamura, et al.The Development and Use of a Chest Phantom for Optimizing Scanning Techniques on a Variety of Low-Dose Helical Computed Tomography Devices[J].Journal of Computer Assisted Tomography.2003,27(3):364–374.
[2] Maher MM., Kalra MK, Toth TL, et al.Application of rational practice and technicaladvances for optimizing radiation dose for chest CT[J]. J Thorac Imaging.2004,19(1):16-23.
[3] Mayo JR,Aldrich J,Muller NL,et al.Radiation exposure at chest CT: a statement of the Fleischner Society[J]. Radiology.2003,228(1):15-21.
[4] Mettler FJ,Wiest PW,Locken JA,et al. CT scanning: patterns of use and dose[J]. J Radiol Prot.2000,20(4):3533-3559.
[5] Diederich S , Lenzen H , Wormanns W, et al . Pulmonary nodules experimental and clinical studies at low-dose CT[J].Radiology.1999;213(1):289-298.
[6] Shrimpton P C, Edyvean S. CT scanner dosimetry[J].Br J Radiol, 1998; 71(841): 1-3.
[7]张春红,林大全.探析我国仿真人体模型中的仿生技术[J].机械.2009,36(1):1-2.
[8]张春红,林大全.中国成人仿真人体模型的参数研究[J].机械.2009,36(7):1-3.
[1] Yoshihisa M, Yukihiro T, Yoshimasa N, et al.The Development and Use of a Chest Phantom for Optimizing Scanning Techniques on a Variety of Low-Dose Helical Computed Tomography Devices[J]. Journal of Computer Assisted Tomography.2003,27(3):364–374.
[2] Nevzat K,Macit A.Low-dose CT:practices and strategies of radiologists in university hospitals[J].Diagn Interv Radiol .2006,12(1):3-8.
[3] Nickoloff EL,Alderson PO.Radiation exposures to patients form CT:reality ,public perception and policy[J]. AJR.2001,177(1):285 - 287.
[4] Maher MM, Kalra MK, Toth TL, et al. Application of rational practice and technical advances for optimizing radiation dose for chest CT[J]. J Thorac Imaging .2004, 19(1):16-23.
[5] Hart D, Wall BF. UK population dose from medical X-ray examinations[J]. Eur J Radiol.2004, 50(3):285–291.
[6] Xiaohua Zhu,Jianqun Yu,Zheng Huang. Low-Dose Chest CT: Optimizing Radiation Protection for Patients[J]. AJR.2004,183(3):809-816.
[7] Yoshiharu O,Hisanobu K,Astushi K,et al. Influence of detector collimation and beam pitch for identification and image quality of ground-glass attenuation and nodules on 16-and 64-detector row CT systems:Experimental study using chest phantom[J].Eur J Radiology.2007,64(3):406-413.
[8] John D,Kostas P,Panos P,et al.Conceptus radiation dose and risk from chest screen-film radiography[J]. Eur Radiol.2003,13(3):406-412.
[9]曾勇明.数字X线成像技术操作规范与剂量优化[M].重庆:重庆出版社.2009,117-118.
[10]张春红,林大全.中国成人仿真人体模型的参数研究[J].机械.2009,36(7):1-3.
[11]张春红,林大全.探析我国仿真人体模型中的仿生技术[J].机械.2009,36(1):1-2.
[12]曾勇明,张志伟,梁开运,等.双能量减影胸部成像模拟肺部病变检出的实验研究[J].重庆医科大学学报.2007,32(7):686-688.
[13]曾勇明,吴富荣,张志伟,等.数字X线摄影辐射剂量与图像质量相关性的实验研究[J].重庆医科大学学报.2009,34(11):1517-1520.
[1] Nevzat K,Macit A.Low-dose CT:practices and strategies of radiologists in university hospitals[J].Diagn Interv Radiol.2006,12(1):3-8.
[2] Maher MM, Kalra MK, Toth TL,et al. Application of rational practice and technical advances for optimizing radiation dose for chest CT[J]. J Thorac Imaging.2004,19(1):16-23.
[3] Mayo JR, Aldrich J, Muller NL,et al. Radiation exposure at chest CT: a statement of the Fleischner Society[J]. Radiology.2003,228(1):15-21.
[4] Mettler FA Jr, Wiest PW, Locken JA, Kelsey CA. CT scanning: patterns of use and dose[J]. J Radiol Prot.2000,20(4):3533-3559.
[5] ICRP.Managing patient dose in multi-detector computed tomography(MSCT).ICRP Publication 102.Oxford:Pergamon press,2007.
[6] ICRP.The 2007 recommendations of the International Commission on Radiological Protection 103.Oxford:Pergamon Press,2008.
[7] CEC.Quality criteria for computed tomography,European guidelines[M].EUR 16262.Luxembourg:Commission of the European Communities,1999.
[8] Nevzat K,Macit A.Low-dose CT:practices and strategies of radiologists in university hospitals[J].Diagn Interv Radiol .2006,12(1):3-8.
[9] Nickoloff EL , Alderson PO. Radiation exposures to patients form CT:reality ,public perception and policy[J]. AJR.2001,177(1):285-287.
[10]Maher MM, Kalra MK, Toth TL,et al. Application of rational practice and technical advances for optimizing radiation dose for chest CT[J]. J Thorac Imaging .2004, 19(1):16-23.
[11]Hart D, Wall BF. UK population dose from medical X-ray examinations[J]. Eur J Radiol.2004, 50(3):285-291.
[12]白玫,刘彬,郑钧正,等.两种介入放射学(CT和PTCA)所致患者辐射剂量研究[J].中国医学影像技术.2007,23(12):1876-1881.
[13]张春红,林大全.探析我国仿真人体模型中的仿生技术[J].机械.2009,36(1):1-2.
[14]张春红,林大全.中国成人仿真人体模型的参数研究[J].机械.2009,36(7):1-3.
[15]Lloyd DC,Edwards AA,Leonard A,et al.Chromosomal aberrations in human lymphocytes induced in vitro by very low doses of X-rays[J].Int J Radiat Biol.1992,61(3):335-343.
[1] Nevzat K,Macit A.Low-dose CT:practices and strategies of radiologists in university hospitals[J].Diagn Interv Radiol. 2006,12(1):3-8.
[2] Nickoloff EL , Alderson PO. Radiation exposures to patients from CT:reality ,public perception and policy[J] . AJR.2001,177(2):285-287.
[3] Shrimpton P C, Edyvean S. CT scanner dosimetry[J].Br J Radiol.1998,71(841): 1-3.
[4]郑钧正,贺青华,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.2000,20 (增刊) : s7.
[5] Diederich S , Lenzen H , Wormanns W, et al . Pulmonary nodules experimental and clinical studies at low-dose CT[J].Radiology.1999,213(1):289-298.
[6] Naidich DP, Marshall CH, Gribbin C, et al. Low - dose CT of the lungs: preliminary observation [ J ]. Radiology.1990,175 ( 3 ) : 729 -731.
[7]殷少龙,赵春龙,于文东,等.低剂量螺旋CT扫描在肺部空洞性病变诊断中的价值[J].实用预防医学.2008,15(3):851.
[8] Yoshiharu O,Hisanobu K,Astushi K,et al. Influence of detector collimation and beam pitch for identification and image quality of ground-glass attenuation and nodules on 16-and 64-detector row CT systems:Experimental study using chest phantom[J].Eur J Radiology.2007,64(2):406-413.
[9] Mahesh M, Scatarige J C, Cooper J, et al. Dose and pitch relationship for a particular multislice CT scanner[J]. Am J Roentgenol.2001,177(6): 1273-1275.
[10]周泽俊,胡永胜.多层螺旋CT螺距,层厚和重建间隔关系对图像质量影响[J].CT理论与应用研究.2008,17(1):21-26.
[11]路鹤晴,朱国英,卓维海,等.医用X射线CT辐射剂量影响因素研究[J].上海医学影像.2008,17(2):93-96.
[12]Hidajt N,Maurer J,Schroder RJ,et al.Relationship between physical dose quantities and patient dose in CT[J].Bri J Radiol.1999,72:556-561.
[13]Mannudeep K,Michael M,Thomas L,et al.Techniques and applications of automatic tube current modulation for CT[J].Radiology.2004,233(12):649-657.
[14]Hidajat N, Maurer J, et al. Relationships between physical dose quantities and patient dose in CT[J]. Br J Radiol.1999,72(858):556-561.
[15]贾明轩,张煊,刘为,等.CT检查所致病人剂量的简便估算方法[J].中华放射医学与防护杂志.2001,21(5):374-376.
[16]Rusinek H,Naidich D,et al.Pulmonary nodule detection:low-dose versus conventional CT[J].Radiology.1998,209(1):243-249.
[17]Nitta N,Takahashi M,Murata K,et al.Ultra low-dose helical CT of the chest[J].AJR.1998,171(2):383-385.
[18]朱天照,蒋学祥,唐光键.螺旋CT肺结节检出率的实验研究[J].中国医学影像技术.2003,19(7):833-835.
[19]Itoh S,Ikeda M,Arahata S,et al. Lung cancer screening: minimum tube current required for helical CT[J]. Radiology.2000,215(1):175-183.
[20]Kaneko M, Kusumoto M, Kobayashi T, et al. Computed tomography screening for lung carcinoma in Japan[J]. Cancer .2000,89 (Suppl) : 2485 - 2488.
[21]Yoshihisa Muramatsu, Yukihiro Tsuda, Yoshimasa Nakamura, et al.The Development and Use of a Chest Phantom for Optimizing Scanning Techniques on a Variety of Low-Dose Helical Computed Tomography Devices[J].Journal of Computer Assisted Tomography.2003,27(3):364–374.