CT固定管电流模式下PET-CT受检者的有效剂量研究  

Study on the effective dose for patient receiving PET-CT under various fixed tube currents mode

作　　者：梁子威 耿建华 赵葵[1] 王奕斌 杜召猛 毕高畅 齐雍鹤 吴宁 郑容 LIANG Zi-wei;GENG Jian-hua;ZHAO Kui

机构地区：[1]浙江大学医学院附属第一医院PET,CT中心,浙江杭州310003 [2]国家癌症中心,中国医学科学院北京协和医学院肿瘤医院核医学科及PET,CT中心,北京100021

出　　处：《中国医学装备》2018年第4期10-13,1,共4页China Medical Equipment

基　　金：中国癌症基金会北京希望马拉松专项基金(LC2013A13和LC2016A02)“PET/CT的辐射剂量和图像质量的模型研究”和“PET/CT及SPECT;SPECT/CT受检者辐射剂量的研究”;国际科技合作项目(2009DFA32960)“PET/CT脑分子影像研究与应用平台及针灸中枢机理探索”

摘　　要：目的:研究正电子发射断层扫描-CT(PET-CT)在固定管电流模式下受检者的有效剂量,为确定最佳临床扫描方案提供参考依据。方法:采用Discovery Elite型PET-CT,CT扫描的有效剂量采用Model RS-550型仿真人体模替代受检者试验获得。CT采集条件为管电压120 k V,固定管电流范围在30~250 m A,20 m A为间隔,螺距为0.984和1.375,转速为0.5 s/转和0.8 s/转。模拟临床PET-CT的分段扫描方式对仿真人体模型进行全身扫描,记录各种扫描条件下的剂量长度乘积(DLP),计算有效剂量(EDCT)。结果:固定管电流模式下CT部分有效剂量,范围为1.05~18.99 m Sv,并且随管电流及转速(s/转)的增加线性增加,随螺距的增加线性降低。结论:对确定的受检者,固定管电流模式下,不同的采集条件,CT部分有效剂量差异较大。Discovery Elite型有效剂量低于Discovery ST-16型。因此可根据不同的临床需求,在保证图像质量的前提下,对不同机型,灵活选择不同的CT扫描条件,可有效降低受检者的有效剂量。Objective:To research the effective dose for patient receiving PET-CT under fixed tube currents mode so as to provide reference bases for determining optimum clinical scan scheme.Methods:The PET-CT of Discovery Elite was adopted as experiment equipment,and the effective dose of CT scan was obtained from simulated experiment for simulation phantom(Model RS-550).Collected conditions of CT included that the current range of fixed tube was 30-250 mA with an interval of 20 mA,and tube voltage was 120 kV,and screw pitches were 0.984 and 1.375,and the rotate speeds were 0.5 s/R and 0.8s/R.The segmented scan mode that simulated clinical PET-CT was implemented for whole body of phantom.Besides,the dose-length products(DLP)under various scan conditions were recorded,and the effective dose was further calculated.Results:The range of effective dose caused by CT under fixed tube current mode was between 1.05 and 18.99 mSv.And with increasing of current and rotate speed,the effective dose increasing linearly,while with increasing of screw pitches,it decreasing linearly.Conclusion:For a certain patient,there is a noteworthy phenomenon is the difference of effective dose among various collecting conditions was larger under fixed tube current scan mode,and the effective dose of Discovery Elite is lower than that of Discovery ST-16.Therefore,according to different clinical requirement,flexible choosing different CT scan condition that aimed at different machine type can effectively reduce effective dose for patient under the precondition of ensuring image quality

关 键 词：正电子发射断层扫描-CT 固定管电流 受检者 有效剂量 

分 类 号：R814.2[医药卫生—影像医学与核医学]