基于蒙特卡罗数学模型评价不同螺距冠状动脉CCTA受检者辐射剂量的特点与验证

辐射防护 ›› 2017, Vol. 37 ›› Issue (2): 131-137.

基于蒙特卡罗数学模型评价不同螺距冠状动脉CCTA受检者辐射剂量的特点与验证

刘潇, 曾勇明, 郁仁强, 王杰, 孙静坤

重庆医科大学附属第一医院放射科,重庆 400016

收稿日期:2016-04-12 出版日期:2017-03-20 发布日期:2021-11-11
通讯作者: 曾勇明。E-mail:zeng-ym@vip.sina.com
作者简介:刘潇(1981—),男,2005年毕业于重庆医科大学医学影像系,现为重庆医科大学影像医学与核医学专业在读硕士研究生。E-mail:lx5937661@qq.com
基金资助:
国家临床重点专科建设项目基金(国卫办[2013]544号);重庆市卫生局科研基金(10-2-055)。

Estimation and validation of radiation dose to patients subjected to high-pitch and standard-pitch CCTA using Monte Carlo software

Liu Xiao, Zeng Yongming, Yu Rengqiang, Wang Jie, Sun Jingkun

The Radiology Department, The First Affiliated Hospital of Chongqing Medical University,Chongqing 400016

Received:2016-04-12 Online:2017-03-20 Published:2021-11-11

摘要/Abstract

摘要： 收集61例采用双源CT Flash大螺距冠状动脉CCTA (Coronary Computed Tomography Angiography,CCTA)受检者资料,按WHO亚洲人体质量指数(BMI )标准将研究对象分为三组:正常组(12例)、超重组(41例)和肥胖组(8例),应用蒙特卡罗(Monte Carlo)数学模型软件计算三组受检者大螺距与常规螺距行CCTA的器官剂量,比较两种螺距CCTA时受检者的器官剂量分布特点及两种螺距CCTA的有效剂量变化幅度,并与大螺距模式下CT设备直接读取法所得有效剂量值进行比较。结果表明,用蒙特卡罗软件计算的双源CT大螺距CCTA受检者的器官剂量比常规螺距技术的剂量降低约70%,其中心脏、胸腺的器官剂量下降最为明显,降幅最大约80%;三组CCTA受检者大螺距较常规螺距的有效剂量(E)均降低明显(p<0.05),正常组使用大螺距技术后有效剂量E降幅最为明显;大螺距模式下数学模型软件模拟有效剂量E与CT设备所测有效剂量E间的偏差度小于50%。说明Monte Carlo数学模型软件可用于检查前预估或回顾性分析CCTA扫描时受检者的器官剂量与有效剂量的分布情况,并预判CCTA大螺距模式对受检者的胸部器官剂量和有效剂量,从而达到了降低辐射剂量的目的,尤其对BMI较小的受检者(如儿童)控制辐射风险更具意义。对开展低剂量CT技术具有一定实际意义。

关键词: 冠状动脉造影, 双源CT, 体层摄影术, 数学模型, 辐射剂量

Abstract: The distribution characteristics of radiation dose of Coronary Computed Tomography Angiography (CCTA) with high-pitch and standard-pitch is studied using Monte Carlo simulation. The data from 61 patients subjected to high-pitch CCTA using the dual source CT scanner were collected and divided into 3 groups according to the BMI classification for Asians recommended by WHO: normal group (12 cases), overweight group (41 cases) and obese group (8 cases). Organ dose and effective dose (E) of the three groups with high-pitch and standard-pitch CCTA were calculated using Monte Carlo software. In high-pitch mode, the effective dose values calculated by Monte Carlo software were compared with the direct data readings from the CT equipment. The results showed that the organ dose of high-pitch CCTA calculated by the Monte Carlo software was about 70% lower than that of standard-pitch CCTA on the dual source spiral CT. The most significant reductions in organ doses were found for heart and thymus, which have decreased by about 80%. For all the 3 groups, the effective doses of high-pitch CCTA were significantly lower than those of the standard-pitch CCTA (p<0.05), and the most obvious reduction in E was found in patients of the normal group subjected to the high-pitch CCTA. In high-pitch mode, deviation in E between the Monte Carlo simulation and the reading of the CT device was less than 50%. This suggested that, as a new clinical calculation method for radiation dose, Monte Carlo simulation can be used for prediction or retrospective analysis of the distribution of organ dose and E in CCTA. It is also indicated that the chest organ dose and effective dose can be significantly reduced with the high-pitch CCTA, and this will subsequently decrease the radiation risk, especially for the subjects of smaller BMI (such as children). This study has a potential for practical applications in development of low dose CT technology.

Key words: Coronary Computed Tomography Angiography (CCTA), dual source computed tomography, computed tomography, mathematical model, radiation dose

中图分类号:

TL72

刘潇, 曾勇明, 郁仁强, 王杰, 孙静坤. 基于蒙特卡罗数学模型评价不同螺距冠状动脉CCTA受检者辐射剂量的特点与验证[J]. 辐射防护, 2017, 37(2): 131-137.

Liu Xiao, Zeng Yongming, Yu Rengqiang, Wang Jie, Sun Jingkun. Estimation and validation of radiation dose to patients subjected to high-pitch and standard-pitch CCTA using Monte Carlo software[J]. RADIATION PROTECTION, 2017, 37(2): 131-137.

参考文献

[1] Tatsugami F,Husmann I,Herzog BA,et al.Evaluation of a body mass index-adapted protocol for low-dose 64-MDCT coronary angiography with prospective ECG triggering[J].AJR,2009,192(3):635-638.
[2] Slovis TI.CT and computed radiography:the pictures are great,but is the radiation dose greater than required?[J].AJR,2002,179(1):39-41.
[3] Rogers IF.Dose reduction in CT:how low can we go?[J].AJR,2002,179(2):299.
[4] Hara AK, Paden RG, Silva AC, et al.Iterative reconstruction technique for reducing body radiation dose at CT: Feasibility study[J]. Am J Roentgenol, 2009,193(3):764-771.
[5] Moscariello A, Takx RA, Schoepf UJ, et al.Coronary CT angiography: image quality, diagnostic accuracy, and potential for radiation dose reduction using a novel iterative image reconstruction technique-comparison with traditional filtered back projection[J]. Eur Radiol, 2011, 21(10):2 130-2 138.
[6] 刘彬,白玫,费晓璐,等. SR250软件在估算CT检查中患者器官剂量和有效剂量的应用[J]. 中国医疗设备,2008,23(6):14-16.
[7] Saltybaeva N, Jafari ME, Hupfer M, et al. Estimates of effective dose for CT scans of the lower extremities[J]. Radiology, 2014, 273(1):153-159.
[8] Romero Corral A,Somers VK,Sierra-Johnson J,et al.Accuracy of body mass index to diagnose obesity in the adult general population[J].Int J Obes (1.ond),2008,32(6):959-966.
[9] 陆再英,钟南山.内科学[M].北京:人民卫生出版社,2008:807-809.
[10] May MS, Deak P, Kuettner A, et al. Radiation dose considerations by intra-individual Monte Carlo simulations in dual source spiral coronary computed tomography angiography with electrocardiogram-triggeredtube current modulation and adaptive pitch[J]. Eur Radiol, 2012, 22(3):569-578.
[11] Oda S,Utsunomiya D, Funama Y, et al. A low tube voltage technique reduces the radiation dose at retrospective ECG-gated cardiac computed tomography for anatomical and functional analyses[J]. Acad Radiol, 2011, 18(10):991-999.
[12] Museyko O, Heinemann A, Krause M, et al. A low-radiation exposure protocol for 3D QCT of the spine[J]. Osteoporos Int, 2014, 25(3):983-992.
[13] 马大庆.进一步发挥64层CT的临床应用价值[J].中华放射学杂志,2009,43(12):1 237-1 238.
[14] Earls JP,Berman EL,Urban B, 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.
[15] 彭盛坤,曾勇明,郁仁强,等. 新双源CT 冠状动脉CTA 扫描参数与重建算法图像质量的体模研究[J]. 中国医学影像技术, 2013, 29(4): 56-60.
[16] 刘潇,曾勇明. 辐射剂量数学模型在医学影像学的应用及研究进展[J]. 重庆医学, 2013, 24(14):1 650-1 652.
[17] 潘羽唏,邱睿,郑钧正,等. 利用蒙特卡罗建模及估算儿童X-CT检查受照剂量[J]. 辐射防护,2016,36(3):129-134
[18] Donald L,Miller MD,Stephen Baiter,et al.Quality improvement guidelines for recording patient radiation dose in the medical record[J].Vasc Interv Radiol, 2004, 15(3):423-429.
[19] 刘潇,曾勇明,彭盛坤,等.冠状动脉CT血管造影辐射剂量蒙特卡罗软件模拟计算及仿真体模验证[J]. 中华放射医学与防护杂志,2014,34(2):78-81.
[20] Renker M, Ramachandra A, Schoepf UJ, et al. Iterative image reconstruction techniques: applications for cardiac CT[J]. JCCT, 2011, 16(5):225-230.
[21] Tatsugami F, Kanamoto T, Nakai G, et al. Reduction of the total injection volume of contrast masterial with a short injection duration in 64-detector row CT coronary angiography[J]. Br J Radiology, 2009, 65(13):475-478.
[22] Miller JM, Dewey M, Vavere AL, et al. Coronary CT angiography using 64 detector rows: methods and design of the multi-center trial CORE-64[J]. Eur Radiology, 2009, 19(4):816-828.