高性能CT在心脏扫描中的剂量测量与分析
|
摘要
据世界心脏联盟估计,2005年全球有1750万例患者死于心血管疾病,占当年全球死亡总人数的30%；每年我国有54.4万例死亡原因为心脏性猝死,每天至少有1480例死亡。目前,心脏病的死亡率居高不下,严重威胁着人类的生命健康。如何使心脏病得到精确的诊治,需要结合相应的临床影像学诊断方法。伴随着64排CT出现,特别是近年来高性能CT(诸如双源CT、256层CT和320层CT等)的出现和应用,在拥有高时间分辨力、高空间分辨力和高图像质量的同时,CT在心脏诊断中能够将心脏的形态和功能得以清晰的显示。因此,在目前的心脏临床医学影像诊断中,越来越多的临床医生倾向于高性能CT的选择。与此同时,CT在诊断中所产生的剂量问题,引起业内众多学者的关注；如何在保证临床所需图像质量的前提下,尽可能地降低辐射剂量,从而避免患者由于CT的使用而带来的负面效应,已成为放射领域工作人员所面临的课题之一。
本研究对仿真人体模型进行不同类型的CT扫描,并探讨各种扫描模式下的组织器官剂量。结果表明,256层CT轴扫、螺旋扫、320层CT的1个beat和2个beat相对于64排CT轴扫所造成的9种组织器官剂量的降低范围分别为：36.6%(甲状腺)～58.3%(脊髓)、26.8%(右侧乳腺)～44.4%(脊髓)、21.6%(甲状腺)～68.1%(胃)和18.9%(右侧乳腺)～42.8%。心脏在CT常规扫描中,高性能CT(256层CT和320层CT)对各个组织器官造成的平均吸收剂量要比64排CT轴扫有剂量学上的优势。从辐射剂量的角度出发,建议临床在心脏CT扫描中,要选择256层轴扫和320层1个beat的扫描类型,从而可以降低CT对患者的辐射,利于人类整体辐射剂量的降低。
Objective:To study the radiation dose of High-performance cardiac CT (256-slice CT and 320-slice CT) which advent in recent years, and the radiation dose contribution and distribution irradiated to sensitive organs and tissues surrounding the heart in the cardiac CT scanning.
Method and Materials:The homemade thermoluminescent dosimeter. (TLD) was laid with the simulated human body model. The simulated human body model was scanned with 64-slice CT (axial scan),256-slice CT (axial scan and spiral scan) and 320-slice CT (1 beat and 2 beats) under routine protocols. The average absorbed doses of the thyroid, breast, heart, esophagus, spinal cord, lung, liver, colon and stomach, and the absorbed dose distributions of these tissues and organs were compared with the five scan types to explore the dosimetric advantages formed with the high-performance CT in the cardiac scanning (as opposed to 64-axis scan). Coronary CT angiograms obtained with 256-slice row CT were retrospectively evaluated in 68 clinical patients. An prospective electrocardiographic (ECG) gating was evaluated in 34 patients (group A). The routine retrospectively gated helical technique was then evaluated in 34 consecutive patients (group B). All images were evaluated for image quality, estimated radiation dose.
Result:The statistical analysis of experimental data was done with the software of SPSS17.0as follows:1) Thyroid:As 64-slice CT scan compared with 256-slice CT axial scan and 320-slice CT(one beat), F= 16.409, P values were 0.000 and 0.001 respectively, P< 0.05, the differences were significant; while as 64-slice axial scan compared with 256-slice spiral scan and 320-slice (two beat), P values were 0.224 and 0.778 respectively, P> 0.05, the differences were not statistically significant.2) Breast:As 64-slice axial scan compared with that in the other four types, F=40.368, P values were 0.002, 0.000,0.000 and 0.001 respectively, P< 0.05, the differences were significant. 3) Spinal cord:As 64-slice CT axial scan compared with that in the other four scan types, F=10.131, P values were 0.000,0.001,0.000 and 0.001 respectively, P< 0.05, the differences were significant.4) Esophagus:As 64-slice CT axial scanning compared with that in the other four types, F=10.829, P values were 0.001,0.001,0.000 and 0.000 respectively, P< 0.05, this indicates a significant difference.5) Heart:As 64-slice CT axial scan compared with that in the other four types, F=,28.911, P values were 0.000,0.000,0.000 and 0.000 respectively, P< 0.05, the differences were significant.6) Lungs:As 64-slice CT compared with that in the other four types, F=10.362, P values were 0.001,0.001,0.001 and 0.001 respectively, P< 0.05, the differences were significant.7) Liver:As 64-slice CT compared with 256-slice spiral scan and 320-slice CT of 2 beats, F=1.808,P values were 0.188 and 0.177, the differences were not statistically significant; while as compared with 256-slice axial scan and 320-slice CT of 1 beats, P values were 0.039 and 0.022, the differences were significant.8) Stomach:As 64-slice CT scan compared with that in other four types scanning types, F=59.609, P values were 0.000,0.000,0.000 and 0.001 respectively, P< 0.05, this indicates a significant difference.9) Colon:As 64-slice CT axial scan compared with that in the other four types, F=2.312, P values were 0.175, 0.323,0.145 and 0.294 respectively, P> 0.05, the differences were not statistically significant.10) The average CTDI for group A was (16.92±1.16) mGy, and the average CTDI for group B was (54.31±3.87) mGy, P< 0.05, there was significant difference (t=-53.99,P<0.001). The mean image SNR for group A and group B were (22.66±9.49) and (20.11±9.54) respectively, P> 0.05, there was no significant difference (t=1.12, P=0.27). The mean image CNR for group A and group B were (19.24±8.36) and (16.83±8.47) respectively, P> 0.05, there was no significant difference(t=1.18, P=0.24).
Conclusion:1) Analysis of radiation dosimetry:Through conventional cardiac CT scanning, High-performance CT (256-slice CT and 320-slice CT) has advantage of radiation dosimetry on average absorbed dose of each tissue than 64-slice CT axial scan.2) Radiation protection of sensitive tissue:cardiac CT scanning will not only produce absorbed dose of tissue but also produce absorbed dose of relative tissue. Thus, sensitive tissue such as thyroid, liver, stomach and colon should be protected during cardiac scanning.3) Selection of clinical application:one beat of 320-slice CT and axial scan of 256-slice CT should be first choice during clinical cardiac CT scanning, and the radiation dose should be reduced while maintaining image quality.
本研究对仿真人体模型进行不同类型的CT扫描,并探讨各种扫描模式下的组织器官剂量。结果表明,256层CT轴扫、螺旋扫、320层CT的1个beat和2个beat相对于64排CT轴扫所造成的9种组织器官剂量的降低范围分别为：36.6%(甲状腺)～58.3%(脊髓)、26.8%(右侧乳腺)～44.4%(脊髓)、21.6%(甲状腺)～68.1%(胃)和18.9%(右侧乳腺)～42.8%。心脏在CT常规扫描中,高性能CT(256层CT和320层CT)对各个组织器官造成的平均吸收剂量要比64排CT轴扫有剂量学上的优势。从辐射剂量的角度出发,建议临床在心脏CT扫描中,要选择256层轴扫和320层1个beat的扫描类型,从而可以降低CT对患者的辐射,利于人类整体辐射剂量的降低。
Objective:To study the radiation dose of High-performance cardiac CT (256-slice CT and 320-slice CT) which advent in recent years, and the radiation dose contribution and distribution irradiated to sensitive organs and tissues surrounding the heart in the cardiac CT scanning.
Method and Materials:The homemade thermoluminescent dosimeter. (TLD) was laid with the simulated human body model. The simulated human body model was scanned with 64-slice CT (axial scan),256-slice CT (axial scan and spiral scan) and 320-slice CT (1 beat and 2 beats) under routine protocols. The average absorbed doses of the thyroid, breast, heart, esophagus, spinal cord, lung, liver, colon and stomach, and the absorbed dose distributions of these tissues and organs were compared with the five scan types to explore the dosimetric advantages formed with the high-performance CT in the cardiac scanning (as opposed to 64-axis scan). Coronary CT angiograms obtained with 256-slice row CT were retrospectively evaluated in 68 clinical patients. An prospective electrocardiographic (ECG) gating was evaluated in 34 patients (group A). The routine retrospectively gated helical technique was then evaluated in 34 consecutive patients (group B). All images were evaluated for image quality, estimated radiation dose.
Result:The statistical analysis of experimental data was done with the software of SPSS17.0as follows:1) Thyroid:As 64-slice CT scan compared with 256-slice CT axial scan and 320-slice CT(one beat), F= 16.409, P values were 0.000 and 0.001 respectively, P< 0.05, the differences were significant; while as 64-slice axial scan compared with 256-slice spiral scan and 320-slice (two beat), P values were 0.224 and 0.778 respectively, P> 0.05, the differences were not statistically significant.2) Breast:As 64-slice axial scan compared with that in the other four types, F=40.368, P values were 0.002, 0.000,0.000 and 0.001 respectively, P< 0.05, the differences were significant. 3) Spinal cord:As 64-slice CT axial scan compared with that in the other four scan types, F=10.131, P values were 0.000,0.001,0.000 and 0.001 respectively, P< 0.05, the differences were significant.4) Esophagus:As 64-slice CT axial scanning compared with that in the other four types, F=10.829, P values were 0.001,0.001,0.000 and 0.000 respectively, P< 0.05, this indicates a significant difference.5) Heart:As 64-slice CT axial scan compared with that in the other four types, F=,28.911, P values were 0.000,0.000,0.000 and 0.000 respectively, P< 0.05, the differences were significant.6) Lungs:As 64-slice CT compared with that in the other four types, F=10.362, P values were 0.001,0.001,0.001 and 0.001 respectively, P< 0.05, the differences were significant.7) Liver:As 64-slice CT compared with 256-slice spiral scan and 320-slice CT of 2 beats, F=1.808,P values were 0.188 and 0.177, the differences were not statistically significant; while as compared with 256-slice axial scan and 320-slice CT of 1 beats, P values were 0.039 and 0.022, the differences were significant.8) Stomach:As 64-slice CT scan compared with that in other four types scanning types, F=59.609, P values were 0.000,0.000,0.000 and 0.001 respectively, P< 0.05, this indicates a significant difference.9) Colon:As 64-slice CT axial scan compared with that in the other four types, F=2.312, P values were 0.175, 0.323,0.145 and 0.294 respectively, P> 0.05, the differences were not statistically significant.10) The average CTDI for group A was (16.92±1.16) mGy, and the average CTDI for group B was (54.31±3.87) mGy, P< 0.05, there was significant difference (t=-53.99,P<0.001). The mean image SNR for group A and group B were (22.66±9.49) and (20.11±9.54) respectively, P> 0.05, there was no significant difference (t=1.12, P=0.27). The mean image CNR for group A and group B were (19.24±8.36) and (16.83±8.47) respectively, P> 0.05, there was no significant difference(t=1.18, P=0.24).
Conclusion:1) Analysis of radiation dosimetry:Through conventional cardiac CT scanning, High-performance CT (256-slice CT and 320-slice CT) has advantage of radiation dosimetry on average absorbed dose of each tissue than 64-slice CT axial scan.2) Radiation protection of sensitive tissue:cardiac CT scanning will not only produce absorbed dose of tissue but also produce absorbed dose of relative tissue. Thus, sensitive tissue such as thyroid, liver, stomach and colon should be protected during cardiac scanning.3) Selection of clinical application:one beat of 320-slice CT and axial scan of 256-slice CT should be first choice during clinical cardiac CT scanning, and the radiation dose should be reduced while maintaining image quality.
引文
[1]Brenner DJ, Hall EJ. Computed tomography--an increasing source of radiation exposure [J]. N Engl J Med,2007,357(22):2277-2284.
[2]Scanff P, Donadieu J, Pirard P, Aubert B. Population exposure to ionizing radiation from medical examinations in France [J]. Br J Radiol,2008, 81:204-213.
[3]Wiest PW, Locken JA, Heintz PH, Mettler FA Jr. CT scanning:a major source of radiation exposure [J]. Semin Ultrasound CT MR,2002,23:402-410.
[4]裴海琴.医用X-CT机发展与技术应用[J].大众标准化,2003,12：35-36.
[5]Phantoms for performance evaluation and quality assure of CT scanners [R]. AAPM. REPORT No.1.1977.
[6]Specification and Acceptance testing of Computed Tomography Scanners [R]. AAPM. REPORT No.39.1993.
[7]林意群,冯晓刚,洪德明,等.用Catphan体模进行CT机的QA检测方法研究[J].中国医学物理杂志,1999,16(3)：161-164.
[8]GB17589-1998.X射线计算机断层摄影装置影像质量保证检测规范[S].
[9]周诚,沈云.多层螺旋CT的图像重组原理和技术进展[J].中华放射学杂志,2006,40：(9)991-993.
[10]McCollough CH. Automatic exposure control in CT:are we done yet? Radiology,2005,237(3):755-756.
[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,2008,2(17)：93-136.
[12]Francis R, Verdun D,Lepori PM, et al. Management of patient dose and image noise in routine pediatric CT abdominal examination [J]. Eur Radiol, 2004,14:835-841.
[13]李婧,张莹.多层螺旋CT低剂量与图像质量相关性的研究[J].医疗装备,2009,22(5)：11-14.
[14]Report EUR 16262. European Guidelines on Quality Criteria for Computed Tomography.2000.
[15]IAEA, ILO, WHO, et al. Internation basic Standard of radiation Protection and safety of radiation source [P]. IAEA Safety Serious No.115. Vienna.1996.
[16]蒋瑾.冠状动脉CT成像应用现状与影响成像的技术条件[J].医学进展,2009,3：96-98.
[17]Klass O, Jeltsch M, Feuerlein S, et al. Prospectively gated axial CT coronary angiography:preliminary experiences with a novel low-dose technique [J]. Eur Radiol,2008,19(4):829-836.
[18]Husmann L, Valenta I, Gaemperli O, et al. Feasibility of low-dose coronary CT angiography:first experience with prospective ECG-gating [J]. Eur Heart J,2008,29:191-197.
[19]李伯扬,马宁耶.双源CT (dual-source computed tomography)在心脏成像和冠脉造影的应用与发展[J].医疗装备,2007,20(8)：21-22.
[20]Oliver K, Matthew W, et al. Prospectively gated axial CT coronary angiography:comparison of image quality and effective radiation dose between 64-and 256-slice CT [J]. Eur Soc Radiol,2010,20:1124-1131.
[21]Lucia JM., Joost JH. Jacob G, et al. Scan time and patient dose for thoracic imaging in neonates and small children using axial volumetric 320-detector row CT compared to helical 64-,32-, and 16-detector row CT acquisitions [J]. Pediatr Radiol,2010,40:294-300.
[22]Brodoefel H, Reimann A, Heuschmid M, et al. Non-invasive coronary angiography with 16-slice spiral computed tomography:image quality in patients with high heart rates [J]. Eur Radiol,2006,16:1434-1441.
[23]Cordeiro MA, Miller JM, Schmidt A, et al. Non-invasive half millimeter 32 detector row computed tomography angiography amlurately excludes significant stenoses in patients with advanced coronary artery disease and high calcium scores [J]. Heart,2006,92:589-597.
[24]Ehara M, Surmely JF, Kawai M, et al. Diagnostic accuracy of 64-slice computed tomography for detecting angiographically significant coronary artery stenosis in an unselected consecutive patient population:comparison with conventional invasive angiography [J]. Circ J,2006,70:564-571.
[25]杨珉.心脏CT[J].放射学实践,2007,22(5)：437-439.
[26]Kalra M, Maher M, Toth T, et al. Strategies for CT radiation dose optimization [J]. Radiology,2004,230(3):619-628.
[27]Willis C, Slovis T. The ALARA concept in pediatric CR and DR:dose reduction in pediatric radiographic exams-a white paper [J].2005,184:373-374.
[28]余小锷,冯小刚.CT设备剂量的测量与分析[J].中华放射医学与防护杂志,2002,22(4)：286-288.
[29]Christof B, Anja R. Quantitative parameters to compare image quality of non-invasive coronary angiography with 16-slice,64-slice and dual-source computed tomography [J]. Eur Soc Radiol,2009,19:584-589.
[30]刘涛,胡克.双源CT的辐射剂量研究[J].技术·新知,2009,3：157-158.
[31]Shinichiro M, Kanae N, et al. Effective doses in subjects undergoing computed tomography cardiac imaging with the 256-multislice CT scanner [J]. Radiology,2008,65(3):442-448.
[32]Dianna M, Charles S. Low-Dose Coronary Artery Computed Tomography Angiogram of an Infant with Tetralogy of Fallot Using a 256-Slice Multidetector Computed Tomography Scanner[J]. EBSCO,2009,6(30):1037-1043.
[33]International Commission on Radiological Protection.1990 recomm-endations of the International Commission on Radiological Protection. Oxford: Pergamon Press. ICRP Publication 60, Ann ICRP 21,1991.
[34]International Commission on Radiological Protection.2007 reco-mmendations of the International Commission on Radiological Protection. New York:Elsevier; ICRP Publication 103, Ann ICRP 37,2007.
[35]陈大伟,刘春生.减小乳腺检查中吸收剂量的实验研究[J].中华放射医与防护杂志,2002,22(6)445-446.
[36]杨珂,柳怡,李福生,等.CT剂量研究进展[J].中国辐射卫生,2006,15(3)：374-376.
[37]Brisse HJ, Robilliard M. Assessment of organ absorbed doses and estimation of effective doses from pediatric anthropomorphic phantom meas-urements for multi-detector row CT with and without automatic exposure control [J]. Health Physics,2009,97(4):303-314.
[38]李福生,宁尚义.头、全身CT检察中甲状腺、性腺辐射剂量与防护[J].中国辐射卫生,2009,1(18)：121-122.
[39]Dauer LT, Casciotta KA, Erdi YE, et al. Radiation dose reduction at a price the effectiveness of male gonadal shield during helical CT scans [J]. BMC Med Imaging,2007,5(7):1186-1193.
[40]傅强,卢涛,张琳.头部CT扫描时防护围脖对减少甲状腺辐射剂量的评估[J].中国辐射卫生,2008,7(1)：13-14.
[41]McLaughlin DJ, Mooney RB. Dose reduction to radiosensitive tissues in CT. Docommercially available shields meet the users'needs [J]? Clin Radiol, 2004,59(5):446-450.
[42]Hopper KD, Neuman JD, King SH, Kunselman AR. Radioprotection to the eye during CT scanning [J]. AJNR Am J Neuroradiol,2001,22(6): 1194-1198.
[43]Heaney DE, Norvill CA. A comparison of reduction in CT dose through the use of gantry angulations or bismuth shields [J]. Australas Phys Eng Sci Med,2006,29(2):172-178.
[44]Shortt CP, Malone L. Radiation protection to the eye and thyroid during diagnostic cerebral angiography:A phantom study [J]. Med Imaging Radiat Oncol,2008,52:365-369.
[45]Frush DP, Soden B, Frush KS, et al. Improved pediatric multidetector body CT using a size-based color-coded format. Am J Roentgenol,2002,178: 721-726.
[46]SioviS TL. CT and computed Radiography:the p ictures are great; but Is the radiation dose greater than required [J]? Am J Roentgenol,2002, 179:39-41.
[47]National Council on Radiation Protection and Measurements. Ionizing radiation exposure of the population of the United States. Bethesda, MD: National Council on Radiation Protection and Measurements,1987. Report No. 93. NCRP Report No.93.
[48]Dinkel HP, Sonnenschein M, Hoppe H, et al. Low-dose multislice CT of the thorax in follow-up of malignant lymphoma and extrapulmonary primary tumors [J]. Enr Radiol,2003,13(6):1241-1249.
[49]LudlowJB, Davies-Ludlow LE, Brooks SL, et al. Dosimetry of 3 CBCT deviees for oral and maxillofacial radiology:CB Mereuray, NewTom 3G and i-CAT [J]. Dentomaxillofacil Radlol,2006,35:219-226.
[50]方冬.ImPlagraphy牙颌面锥形束CT与多层螺旋CT的图像质量及辐射剂量对比研究[J].中华老年口腔医学杂志,2008,6(4)：226-229.
[51]李桂萍,王胜林,王爱辉,等.CT和钼靶诊断乳腺疾病价值的对照分析[J].实用放射学杂志,2004,20(6)540-543.
[52]杜永,沈天真,陈可敏.乳腺癌的影像学检测[J].国外医学·临床放射学分册,1994,17(3)：130-131.
[53]刘明娟,黄兆民,郭燕,等.螺旋CT在乳腺疾病的应用[J].中国医学影像技术,2001,17(8)：746-748.
[54]李桂萍,王胜林,王爱辉,等.CT和钼靶诊断乳腺疾病价值的对照分析[J].实用放射学杂志,2004,20(6)：540-543.
[55]李桂萍,王胜林,李汉茹,等.乳腺良恶性病变CT表现[J].实用放射学杂志,2003,19(10)：875-878.
[56]Izzo L, Stasolla A, Basso L, et al, Characterization of tumoral lesions of the breast:p reliminary experience with multislice sp iral CT [J]. Exp Clin Cancer Res,2005,24(2):209-215.
[57]Rampersaud YR, Foley KT, Shen AC. Radiation exposure to the spine surgeon during fluoroscopically assisted pedicle screw insertion [J]. Spine, 2000,25(20):2637-2645.
[58]Synowitz M. Kiwit J. Surgeon's radiation exposure during percutaneous vertebroplasty [J]. J Neurosurg Spine,2006,4(2):106-109.
[59]van Walsum T, van de Kraats EB, Voormolen MH, et al. Navigation with three dimensional rotational radiographic data for transpedicular percutaneous needle introduction:feasibility and comparison with fluoroscopic guidance [J]. J Vasc Interv Radiol,2006,17(9):1511-1518.
[60]Ricci WM, Russell TA, Kahler DM, et al. A comparison of optical and electromagnetic computer assisted navigation systems for fluoroscopic targeting [J]. J Orthop Trauma,2008,22(3):190-194.
[61]Gardner MJ, Citak M, Kendoff D, et al. Decreased navigated drilling time using an external guide stabilising device [J]. Injury,2007,38(7):755-758.
[62]Parkin DM, Bray F, Ferlay J, et al. Global cancer estatisties [J]. CA Caneer J Clin,2005,55(2):74-108.
[63]Sutton CD, White SA, Marshall LJ, et al. Endoscopic assisted intrathoraeie oesophagogastro-stomy without thoraeotomy for tumours the lower oesophagusa and cardia [J]. Eur J Surg Oncol,2002,28(l):46-48.
[64]Ellis FH, Watkins Jr, KrasnaMJ, et al. Staging of eareinoma of the esophagus and cardia:a comparison of differentst aginge riteria [J]. J Surgoneol, 1993,52(6):231-235.
[65]Hunold P, Vogt FM, Schmemmnd A, et all. Radiation exposure during cardiac CT:effective doses at multi2detector row CT and electronbeam CT [J]. Radiology,2003,226(1):145-152.
[66]郝涛,罗宏.CT探测器的技术特点和发展趋势[J].中国医疗设备,2008,1(23)：55-57.
[67]聂聪.多层CT探测器的发展[J].中国医学装备,2008,5(7)：68-71.
[68]De Jaeger K, Seppenwoolde Y, Boersma LJ. Pulmonary function: Following high-dose radiotherapy of non-small-cell lung cancer [J]. Int J Radiat Oncol Biol phys,2003,55(5):1331-1340.
[69]Gopal R, Tueker SL, Komaki R. The relationship between local dose and loss of function for irradiated lung [J]. Int J Radiat Oncol Biol Phys,2003, 56(1):106-113.
[70]Robnett TJ, Maehtay M, EVines E. Factors predicting severe Radiation pneumonitis in patient receviving definitive chemoradiation for Lung cancer [J]. Int J Radiat Oncol Biol phys,2000,48(1):89-94.
[71]Monson JM, Stark P, Reilly JJ. Clinical radiation pneumonitis and Radiographic changes after thoracic radiation therapy for lung carcinoma [J]. Caneer,1998,82(5):842-850.
[72]Pandharipande PV, Krinsky GA, Rusinek H, et al. Perfusion imaging of the liver:current challenges and future goals [J]. Radiology,2005,3 (234):661-673.
[73]Schindera ST, Nelson RC, Mukundan S Jr, et al. Hypervascular liver tumors:low tube voltage, high tube current multi-etector row CT for enhanced detection enhanced detection-hantom study [J]. Radiology,2007,246(1): 125-132.
[74]彭永伦,郭洪涛,张莹,等.CT扫描条件对CT值和辐射剂量指数的影响[J].中国计量,2007,5(1)：62-63.
[75]Nakayama Y, Awai K, Funama Y, et al. Abdominal CT with low tube voltage:preliminary observations about radiation dose contrast enhancement image quality and noise [J]. Radiology,2005,237(3):945-951.
[76]李松年.现代全身CT诊断学(下卷)[M].北京：中国医药科技出版社,2001：979-980.
[77]Kazerooni EA, Quint LE, Francis IR. Doudenal neoplasms predictive value CT determining malignance on tumor resectability [J]. AJR,1992, 15(2):303-309.
[78]李果珍.临床CT诊断学[M].北京：中国科技出版社,1994.
[79]Cho JS, Kim CM. Preoprative assessment of gastric carcinoma:value of two phase dynamic CT with mechanical IV injection of contrast material [J]. AJR,1994,163(1):69-75.
[80]Diederich S, Wormanns D, Semik M, et al. Screening for lung cancer with low dose spiral CT:prevalence in 817 a sympotomatic smokers [J]. Radiology,2002,222:773-781.
[81]Karabulut N, Toru M, Gelebek V, et al. Comparison of low dose and standard dose helical CT in the evaluation of pulmonary nodules [J]. Eur Radiol,2002,12:2764-2769.
[82]Pastorino U, Bellomi M, Landoni C, et al. Early lung cancer detection with s-piral CT and positronemission tomography in heavy smokers:2 years results [J]. Lancet,2003,362:593-597.
[83]聂永康,蔡祖龙,赵绍宏.低剂量螺旋CT筛选检查早期肺癌的初步研究[J].中华放射学杂志,2002,36：230-234.
[84]Parker SL, Tong T, Bolden S, et al. Cancer statistics 1996 [J]. CA Cancer J Clin,1996,46(1):5-27.
[85]Fletcher JG, Johnson CD, Welch TJ, et al. Optimization of CT colonography technique:prospective trial in 180 patients [J]. Radiology,2000, 216(3):704-711.
[86]Hara AK, Johnson CD, MacCarty RL, et al. CT colonography: single-versus multi-detector row imaging [J]. Radiology,2001,219(2):461-465.
[87]Macari M, Bini EJ, Xue X, et al. Colorectal neoplasms:prospective comparison of thin-section low-dose multi-detector row CT colonography and conventional colonoscopyfor detection [J]. Radiology,2002,224(1):383-392.
[88]Cohnen M, Vogt C, Aurich V, et al. Multi-slice CT-colonography in low-dose technique:preliminary results [J]. RoFo:Fortschritte auf dem Gebiete der Rontgenstrahlen und der Nuklearmedizin,2002,174(7):835-838.
[89]Mollet NR, Cademartiri F, van Mieghem CA, et al. High-resolution spiral computed tomography coronary angiography in patients referred for diagnostic conventional coronary angiography [J]. Circulation,2005,112(15): 2318-2323.
[90]Leber AW, Becker A, Knez A, et al. Accuracy of 64-slice computed tomography to classify and quantify plaque volumes in the proximal coronary system:a comparative study using intravascular ultrasound [J]. J Am Coll Cardiol,2006,47(3):672-677.
[91]Shim SS, Kim Y, Lim SM. Improvement of image quality with beta-blocker premedication on ECG-gated 16-MDCT coronary angiography [J]. AJR Am J Roentgenol,2005,184(2):649-654.
[92]Jakobs TF, Becker CR, Ohnesorge B, et al. Multislice helical CT of the heart with retrospective ECG gating:reduction of radiation exposure by ECG-controlled tube current modulation [J]. Eur Radiol,2002,12(5): 1081-1086.
[93]Deetjen A, Mollmann S, Conradi G, et al. Use of automatic exposure control in multislice computed tomography of the coronaries:comparison of 16-slice and 64-slice scanner data with conventional coronary angiography [J]. Heart,2007,93(9):1040-1043.
[94]Morin RL, Gerber TC, McCollough CH. Radiation dose in computed tomography of the heart[J]. Circulation,2003,107(6):917-922.
[95]Hsieh J, Londt J, Vass M, et al. Step-and-shoot data acquisition and reconstruction for cardiac x-ray computed tomography [J]. Med Phys, 2006,33(11):4236-4248.
[96]Shuman WP, Branch KR, May JM, et al. Prospective versus retrospective ECG gating for 64-detector CT of the coronary arteries: comparison of image quality and patient radiation dose[J]. Radiology,2008, 248(2):431-437.
[97]Earls JP, Berman EL, Urban BA, et al. Prospectively gated transverse coronary CT angiography versus retrospectively gated helical technique: improved image quality and reduced radiation dose[J]. Radiology,2008,246(3): 742-753.
[98]Chao SP, Law WY, Kuo CJ, et al. The diagnostic accuracy of 256-row computed tomographic angiography compared with invasive coronary angiography in patients with suspected coronary artery disease[J]. Eur Heart J, 2010,31(3):1916-1923.
[99]Abada HT, Larchez C, Daoud B, et al. MDCT of the coronary arteries: feasibility of low-dose CT with ECG-pulsed tube current modulation to reduce radiation dose[J]. AJR Am J Roentgenol 2006; 186(6s):S387-S390.
[2]Scanff P, Donadieu J, Pirard P, Aubert B. Population exposure to ionizing radiation from medical examinations in France [J]. Br J Radiol,2008, 81:204-213.
[3]Wiest PW, Locken JA, Heintz PH, Mettler FA Jr. CT scanning:a major source of radiation exposure [J]. Semin Ultrasound CT MR,2002,23:402-410.
[4]裴海琴.医用X-CT机发展与技术应用[J].大众标准化,2003,12：35-36.
[5]Phantoms for performance evaluation and quality assure of CT scanners [R]. AAPM. REPORT No.1.1977.
[6]Specification and Acceptance testing of Computed Tomography Scanners [R]. AAPM. REPORT No.39.1993.
[7]林意群,冯晓刚,洪德明,等.用Catphan体模进行CT机的QA检测方法研究[J].中国医学物理杂志,1999,16(3)：161-164.
[8]GB17589-1998.X射线计算机断层摄影装置影像质量保证检测规范[S].
[9]周诚,沈云.多层螺旋CT的图像重组原理和技术进展[J].中华放射学杂志,2006,40：(9)991-993.
[10]McCollough CH. Automatic exposure control in CT:are we done yet? Radiology,2005,237(3):755-756.
[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,2008,2(17)：93-136.
[12]Francis R, Verdun D,Lepori PM, et al. Management of patient dose and image noise in routine pediatric CT abdominal examination [J]. Eur Radiol, 2004,14:835-841.
[13]李婧,张莹.多层螺旋CT低剂量与图像质量相关性的研究[J].医疗装备,2009,22(5)：11-14.
[14]Report EUR 16262. European Guidelines on Quality Criteria for Computed Tomography.2000.
[15]IAEA, ILO, WHO, et al. Internation basic Standard of radiation Protection and safety of radiation source [P]. IAEA Safety Serious No.115. Vienna.1996.
[16]蒋瑾.冠状动脉CT成像应用现状与影响成像的技术条件[J].医学进展,2009,3：96-98.
[17]Klass O, Jeltsch M, Feuerlein S, et al. Prospectively gated axial CT coronary angiography:preliminary experiences with a novel low-dose technique [J]. Eur Radiol,2008,19(4):829-836.
[18]Husmann L, Valenta I, Gaemperli O, et al. Feasibility of low-dose coronary CT angiography:first experience with prospective ECG-gating [J]. Eur Heart J,2008,29:191-197.
[19]李伯扬,马宁耶.双源CT (dual-source computed tomography)在心脏成像和冠脉造影的应用与发展[J].医疗装备,2007,20(8)：21-22.
[20]Oliver K, Matthew W, et al. Prospectively gated axial CT coronary angiography:comparison of image quality and effective radiation dose between 64-and 256-slice CT [J]. Eur Soc Radiol,2010,20:1124-1131.
[21]Lucia JM., Joost JH. Jacob G, et al. Scan time and patient dose for thoracic imaging in neonates and small children using axial volumetric 320-detector row CT compared to helical 64-,32-, and 16-detector row CT acquisitions [J]. Pediatr Radiol,2010,40:294-300.
[22]Brodoefel H, Reimann A, Heuschmid M, et al. Non-invasive coronary angiography with 16-slice spiral computed tomography:image quality in patients with high heart rates [J]. Eur Radiol,2006,16:1434-1441.
[23]Cordeiro MA, Miller JM, Schmidt A, et al. Non-invasive half millimeter 32 detector row computed tomography angiography amlurately excludes significant stenoses in patients with advanced coronary artery disease and high calcium scores [J]. Heart,2006,92:589-597.
[24]Ehara M, Surmely JF, Kawai M, et al. Diagnostic accuracy of 64-slice computed tomography for detecting angiographically significant coronary artery stenosis in an unselected consecutive patient population:comparison with conventional invasive angiography [J]. Circ J,2006,70:564-571.
[25]杨珉.心脏CT[J].放射学实践,2007,22(5)：437-439.
[26]Kalra M, Maher M, Toth T, et al. Strategies for CT radiation dose optimization [J]. Radiology,2004,230(3):619-628.
[27]Willis C, Slovis T. The ALARA concept in pediatric CR and DR:dose reduction in pediatric radiographic exams-a white paper [J].2005,184:373-374.
[28]余小锷,冯小刚.CT设备剂量的测量与分析[J].中华放射医学与防护杂志,2002,22(4)：286-288.
[29]Christof B, Anja R. Quantitative parameters to compare image quality of non-invasive coronary angiography with 16-slice,64-slice and dual-source computed tomography [J]. Eur Soc Radiol,2009,19:584-589.
[30]刘涛,胡克.双源CT的辐射剂量研究[J].技术·新知,2009,3：157-158.
[31]Shinichiro M, Kanae N, et al. Effective doses in subjects undergoing computed tomography cardiac imaging with the 256-multislice CT scanner [J]. Radiology,2008,65(3):442-448.
[32]Dianna M, Charles S. Low-Dose Coronary Artery Computed Tomography Angiogram of an Infant with Tetralogy of Fallot Using a 256-Slice Multidetector Computed Tomography Scanner[J]. EBSCO,2009,6(30):1037-1043.
[33]International Commission on Radiological Protection.1990 recomm-endations of the International Commission on Radiological Protection. Oxford: Pergamon Press. ICRP Publication 60, Ann ICRP 21,1991.
[34]International Commission on Radiological Protection.2007 reco-mmendations of the International Commission on Radiological Protection. New York:Elsevier; ICRP Publication 103, Ann ICRP 37,2007.
[35]陈大伟,刘春生.减小乳腺检查中吸收剂量的实验研究[J].中华放射医与防护杂志,2002,22(6)445-446.
[36]杨珂,柳怡,李福生,等.CT剂量研究进展[J].中国辐射卫生,2006,15(3)：374-376.
[37]Brisse HJ, Robilliard M. Assessment of organ absorbed doses and estimation of effective doses from pediatric anthropomorphic phantom meas-urements for multi-detector row CT with and without automatic exposure control [J]. Health Physics,2009,97(4):303-314.
[38]李福生,宁尚义.头、全身CT检察中甲状腺、性腺辐射剂量与防护[J].中国辐射卫生,2009,1(18)：121-122.
[39]Dauer LT, Casciotta KA, Erdi YE, et al. Radiation dose reduction at a price the effectiveness of male gonadal shield during helical CT scans [J]. BMC Med Imaging,2007,5(7):1186-1193.
[40]傅强,卢涛,张琳.头部CT扫描时防护围脖对减少甲状腺辐射剂量的评估[J].中国辐射卫生,2008,7(1)：13-14.
[41]McLaughlin DJ, Mooney RB. Dose reduction to radiosensitive tissues in CT. Docommercially available shields meet the users'needs [J]? Clin Radiol, 2004,59(5):446-450.
[42]Hopper KD, Neuman JD, King SH, Kunselman AR. Radioprotection to the eye during CT scanning [J]. AJNR Am J Neuroradiol,2001,22(6): 1194-1198.
[43]Heaney DE, Norvill CA. A comparison of reduction in CT dose through the use of gantry angulations or bismuth shields [J]. Australas Phys Eng Sci Med,2006,29(2):172-178.
[44]Shortt CP, Malone L. Radiation protection to the eye and thyroid during diagnostic cerebral angiography:A phantom study [J]. Med Imaging Radiat Oncol,2008,52:365-369.
[45]Frush DP, Soden B, Frush KS, et al. Improved pediatric multidetector body CT using a size-based color-coded format. Am J Roentgenol,2002,178: 721-726.
[46]SioviS TL. CT and computed Radiography:the p ictures are great; but Is the radiation dose greater than required [J]? Am J Roentgenol,2002, 179:39-41.
[47]National Council on Radiation Protection and Measurements. Ionizing radiation exposure of the population of the United States. Bethesda, MD: National Council on Radiation Protection and Measurements,1987. Report No. 93. NCRP Report No.93.
[48]Dinkel HP, Sonnenschein M, Hoppe H, et al. Low-dose multislice CT of the thorax in follow-up of malignant lymphoma and extrapulmonary primary tumors [J]. Enr Radiol,2003,13(6):1241-1249.
[49]LudlowJB, Davies-Ludlow LE, Brooks SL, et al. Dosimetry of 3 CBCT deviees for oral and maxillofacial radiology:CB Mereuray, NewTom 3G and i-CAT [J]. Dentomaxillofacil Radlol,2006,35:219-226.
[50]方冬.ImPlagraphy牙颌面锥形束CT与多层螺旋CT的图像质量及辐射剂量对比研究[J].中华老年口腔医学杂志,2008,6(4)：226-229.
[51]李桂萍,王胜林,王爱辉,等.CT和钼靶诊断乳腺疾病价值的对照分析[J].实用放射学杂志,2004,20(6)540-543.
[52]杜永,沈天真,陈可敏.乳腺癌的影像学检测[J].国外医学·临床放射学分册,1994,17(3)：130-131.
[53]刘明娟,黄兆民,郭燕,等.螺旋CT在乳腺疾病的应用[J].中国医学影像技术,2001,17(8)：746-748.
[54]李桂萍,王胜林,王爱辉,等.CT和钼靶诊断乳腺疾病价值的对照分析[J].实用放射学杂志,2004,20(6)：540-543.
[55]李桂萍,王胜林,李汉茹,等.乳腺良恶性病变CT表现[J].实用放射学杂志,2003,19(10)：875-878.
[56]Izzo L, Stasolla A, Basso L, et al, Characterization of tumoral lesions of the breast:p reliminary experience with multislice sp iral CT [J]. Exp Clin Cancer Res,2005,24(2):209-215.
[57]Rampersaud YR, Foley KT, Shen AC. Radiation exposure to the spine surgeon during fluoroscopically assisted pedicle screw insertion [J]. Spine, 2000,25(20):2637-2645.
[58]Synowitz M. Kiwit J. Surgeon's radiation exposure during percutaneous vertebroplasty [J]. J Neurosurg Spine,2006,4(2):106-109.
[59]van Walsum T, van de Kraats EB, Voormolen MH, et al. Navigation with three dimensional rotational radiographic data for transpedicular percutaneous needle introduction:feasibility and comparison with fluoroscopic guidance [J]. J Vasc Interv Radiol,2006,17(9):1511-1518.
[60]Ricci WM, Russell TA, Kahler DM, et al. A comparison of optical and electromagnetic computer assisted navigation systems for fluoroscopic targeting [J]. J Orthop Trauma,2008,22(3):190-194.
[61]Gardner MJ, Citak M, Kendoff D, et al. Decreased navigated drilling time using an external guide stabilising device [J]. Injury,2007,38(7):755-758.
[62]Parkin DM, Bray F, Ferlay J, et al. Global cancer estatisties [J]. CA Caneer J Clin,2005,55(2):74-108.
[63]Sutton CD, White SA, Marshall LJ, et al. Endoscopic assisted intrathoraeie oesophagogastro-stomy without thoraeotomy for tumours the lower oesophagusa and cardia [J]. Eur J Surg Oncol,2002,28(l):46-48.
[64]Ellis FH, Watkins Jr, KrasnaMJ, et al. Staging of eareinoma of the esophagus and cardia:a comparison of differentst aginge riteria [J]. J Surgoneol, 1993,52(6):231-235.
[65]Hunold P, Vogt FM, Schmemmnd A, et all. Radiation exposure during cardiac CT:effective doses at multi2detector row CT and electronbeam CT [J]. Radiology,2003,226(1):145-152.
[66]郝涛,罗宏.CT探测器的技术特点和发展趋势[J].中国医疗设备,2008,1(23)：55-57.
[67]聂聪.多层CT探测器的发展[J].中国医学装备,2008,5(7)：68-71.
[68]De Jaeger K, Seppenwoolde Y, Boersma LJ. Pulmonary function: Following high-dose radiotherapy of non-small-cell lung cancer [J]. Int J Radiat Oncol Biol phys,2003,55(5):1331-1340.
[69]Gopal R, Tueker SL, Komaki R. The relationship between local dose and loss of function for irradiated lung [J]. Int J Radiat Oncol Biol Phys,2003, 56(1):106-113.
[70]Robnett TJ, Maehtay M, EVines E. Factors predicting severe Radiation pneumonitis in patient receviving definitive chemoradiation for Lung cancer [J]. Int J Radiat Oncol Biol phys,2000,48(1):89-94.
[71]Monson JM, Stark P, Reilly JJ. Clinical radiation pneumonitis and Radiographic changes after thoracic radiation therapy for lung carcinoma [J]. Caneer,1998,82(5):842-850.
[72]Pandharipande PV, Krinsky GA, Rusinek H, et al. Perfusion imaging of the liver:current challenges and future goals [J]. Radiology,2005,3 (234):661-673.
[73]Schindera ST, Nelson RC, Mukundan S Jr, et al. Hypervascular liver tumors:low tube voltage, high tube current multi-etector row CT for enhanced detection enhanced detection-hantom study [J]. Radiology,2007,246(1): 125-132.
[74]彭永伦,郭洪涛,张莹,等.CT扫描条件对CT值和辐射剂量指数的影响[J].中国计量,2007,5(1)：62-63.
[75]Nakayama Y, Awai K, Funama Y, et al. Abdominal CT with low tube voltage:preliminary observations about radiation dose contrast enhancement image quality and noise [J]. Radiology,2005,237(3):945-951.
[76]李松年.现代全身CT诊断学(下卷)[M].北京：中国医药科技出版社,2001：979-980.
[77]Kazerooni EA, Quint LE, Francis IR. Doudenal neoplasms predictive value CT determining malignance on tumor resectability [J]. AJR,1992, 15(2):303-309.
[78]李果珍.临床CT诊断学[M].北京：中国科技出版社,1994.
[79]Cho JS, Kim CM. Preoprative assessment of gastric carcinoma:value of two phase dynamic CT with mechanical IV injection of contrast material [J]. AJR,1994,163(1):69-75.
[80]Diederich S, Wormanns D, Semik M, et al. Screening for lung cancer with low dose spiral CT:prevalence in 817 a sympotomatic smokers [J]. Radiology,2002,222:773-781.
[81]Karabulut N, Toru M, Gelebek V, et al. Comparison of low dose and standard dose helical CT in the evaluation of pulmonary nodules [J]. Eur Radiol,2002,12:2764-2769.
[82]Pastorino U, Bellomi M, Landoni C, et al. Early lung cancer detection with s-piral CT and positronemission tomography in heavy smokers:2 years results [J]. Lancet,2003,362:593-597.
[83]聂永康,蔡祖龙,赵绍宏.低剂量螺旋CT筛选检查早期肺癌的初步研究[J].中华放射学杂志,2002,36：230-234.
[84]Parker SL, Tong T, Bolden S, et al. Cancer statistics 1996 [J]. CA Cancer J Clin,1996,46(1):5-27.
[85]Fletcher JG, Johnson CD, Welch TJ, et al. Optimization of CT colonography technique:prospective trial in 180 patients [J]. Radiology,2000, 216(3):704-711.
[86]Hara AK, Johnson CD, MacCarty RL, et al. CT colonography: single-versus multi-detector row imaging [J]. Radiology,2001,219(2):461-465.
[87]Macari M, Bini EJ, Xue X, et al. Colorectal neoplasms:prospective comparison of thin-section low-dose multi-detector row CT colonography and conventional colonoscopyfor detection [J]. Radiology,2002,224(1):383-392.
[88]Cohnen M, Vogt C, Aurich V, et al. Multi-slice CT-colonography in low-dose technique:preliminary results [J]. RoFo:Fortschritte auf dem Gebiete der Rontgenstrahlen und der Nuklearmedizin,2002,174(7):835-838.
[89]Mollet NR, Cademartiri F, van Mieghem CA, et al. High-resolution spiral computed tomography coronary angiography in patients referred for diagnostic conventional coronary angiography [J]. Circulation,2005,112(15): 2318-2323.
[90]Leber AW, Becker A, Knez A, et al. Accuracy of 64-slice computed tomography to classify and quantify plaque volumes in the proximal coronary system:a comparative study using intravascular ultrasound [J]. J Am Coll Cardiol,2006,47(3):672-677.
[91]Shim SS, Kim Y, Lim SM. Improvement of image quality with beta-blocker premedication on ECG-gated 16-MDCT coronary angiography [J]. AJR Am J Roentgenol,2005,184(2):649-654.
[92]Jakobs TF, Becker CR, Ohnesorge B, et al. Multislice helical CT of the heart with retrospective ECG gating:reduction of radiation exposure by ECG-controlled tube current modulation [J]. Eur Radiol,2002,12(5): 1081-1086.
[93]Deetjen A, Mollmann S, Conradi G, et al. Use of automatic exposure control in multislice computed tomography of the coronaries:comparison of 16-slice and 64-slice scanner data with conventional coronary angiography [J]. Heart,2007,93(9):1040-1043.
[94]Morin RL, Gerber TC, McCollough CH. Radiation dose in computed tomography of the heart[J]. Circulation,2003,107(6):917-922.
[95]Hsieh J, Londt J, Vass M, et al. Step-and-shoot data acquisition and reconstruction for cardiac x-ray computed tomography [J]. Med Phys, 2006,33(11):4236-4248.
[96]Shuman WP, Branch KR, May JM, et al. Prospective versus retrospective ECG gating for 64-detector CT of the coronary arteries: comparison of image quality and patient radiation dose[J]. Radiology,2008, 248(2):431-437.
[97]Earls JP, Berman EL, Urban BA, et al. Prospectively gated transverse coronary CT angiography versus retrospectively gated helical technique: improved image quality and reduced radiation dose[J]. Radiology,2008,246(3): 742-753.
[98]Chao SP, Law WY, Kuo CJ, et al. The diagnostic accuracy of 256-row computed tomographic angiography compared with invasive coronary angiography in patients with suspected coronary artery disease[J]. Eur Heart J, 2010,31(3):1916-1923.
[99]Abada HT, Larchez C, Daoud B, et al. MDCT of the coronary arteries: feasibility of low-dose CT with ECG-pulsed tube current modulation to reduce radiation dose[J]. AJR Am J Roentgenol 2006; 186(6s):S387-S390.