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

发布时间：2018-05-02 02:16

本文选题：冠状动脉造影 + 双源CT　；参考：《辐射防护》2017年02期

【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(p0.05),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。
[Abstract]:The data of 61 cases of CCTA(Coronary Computed Tomography AngiographyContra (CCTA) with double source CT Flash large pitch coronary artery were collected. According to WHO Asian body mass index (BMI) standard, the subjects were divided into three groups: normal group (n = 12), hyperrecombination group (n = 41) and obese group (n = 8). Monte Carlo Monte Carlo (Monte Carlo Monte Carlo) model software was used to calculate the large pitch and conventional snail in three groups. The organ dose of CCTA, The organ dose distribution characteristics of the two pitch CCTA patients and the effective dose range of the two pitch CCTA were compared and compared with the effective dose values obtained by the direct reading method of CT equipment in the large pitch mode. The results showed that the organ dose of dual-source CT large pitch CCTA patients calculated by Monte Carlo software was about 70 times lower than that of conventional spiral pitch technique, in which the organ dose of heart and thymus was the most obvious. The large pitch (E) of the three groups of CCTA patients was significantly lower than that of the conventional pitch (P 0.05), and the decrease of the effective dose E was the most obvious after the use of the large pitch technique in the normal group. The deviation between effective dose E and effective dose E measured by CT equipment is less than 50 in large pitch mode. The results showed that Monte Carlo mathematical model software could be used to predict or retrospectively analyze the distribution of organ dose and effective dose during CCTA scanning, and to predict the dose and effective dose of chest organ by CCTA large pitch mode. Therefore, the aim of reducing radiation dose is achieved, especially for the lower BMI subjects (such as children) to control the radiation risk. It has certain practical significance for developing low dose CT technique.
【作者单位】：重庆医科大学附属第一医院放射科;
【基金】：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)
【分类号】：R816.2

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