摘要
目的:研究不同机型PET-CT中CT采集条件与受检者有效剂量的关系,为确定适合不同机型的临床最优化采集方案提供参考依据。方法:实验使用GE Discovery ST-16和Discovery Elite两种机型的PET-CT,CT部分所致剂量使用仿真人体模型(Model RS-550)实验获得。CT采集条件:(1)自动管电流30~250 mA,噪声指数(NI)值8~30,间隔2,其他采用中国医学科学院肿瘤医院临床实际采集条件,即管电压120 kV,螺距(Pitch):Discovery ST-16型为1.75,Discovery Elite型为0.984,转速:Discovery ST-16型为0.8 s,Discovery Elite型为0.5 s;(2)自动管电流低限均为30 mA,高限为210~350 mA,间隔为20 mA,NI值为14,其他临床实际采集条件同上;(3)Pitch:Discovery ST-16型分别为1.75、1.375和0.938,Discovery Elite分别为1.375和0.984,管电压120 kV,自动管电流为30~250 mA,NI值为14,转速:Discovery ST-16型为0.8 s,Discovery Elite型为0.5 s;(4)两机型转速均分别为0.5 s、0.8 s和1.0 s,管电压120kV,自动管电流为30~250 mA,NI值14,Pitch:Discovery ST-16型为1.75,Discovery Elite型为0.984。模拟临床PET-CT分段扫描方式使用上述条件分别对仿真人体模型RS-550进行扫描,记录各种条件下剂量长度乘积(DLP),并计算有效剂量(ED_(CT))。结果:①对固定的自动管电流、Pitch及转速,两机型CT部分所致有效剂量随NI值增加而降低,且Discovery ST-16型降低幅度大于Discovery Elite型;②对固定的NI值、Pitch及转速,两机型的ED_(CT)随自动管电流的增加线性增加,Discovery ST-16型增加幅度大于Discovery Elite型;③对固定的自动管电流、NI值及转速,ED_(CT)随Pitch的增加而降低;④对固定的管电流、NI值及Pitch,有效剂量随转速的增加而增加;⑤不同扫描条件下,两机型总有效剂量在4.93~24.00 mSv范围内;⑥在临床扫描条件下,Discovery Elite型受检者ED_(CT)均低于Discovery ST-16型。结论:不同型号的PETCT,在临床使用中多采用不同CT扫描条件,而扫描所致辐射剂量也因此有较�
Objective:To study on the relationship between collecting conditions of CT and effective dose for subject indifferent models of PET-CT in order to provide a reference for the determination of the optimal collecting scheme that could suitdifferent models of PET-CT.Methods:Two models of PET-CT which included GE Discovery ST-16PET-CT and GE DiscoveryElite were adopted as experiment equipment,and the agent dosage of CT part obtained from simulation experiment ofanthropomorphic phantom(Model RS-550).Collecting conditions of CT included:(1)auto-tube current was30-250mA,noiseindex(NI)was8-30,the interval was2,and the other conditions used actually clinical collecting conditions:tube voltage was120kV,and pitches respectively were1.75for ST-16and0.984for Elite,and rotation speeds respectively were0.8s for ST-16and0.5s for Elite.(2)both of low limits of auto tube current of the two models of PET-CT were30mA,and range of high limit wasfrom210to350mA,and the interval was20mA,and NI was14,and the other conditions were the same with above those in(1).(3)Pitch:ST-16respectively chose1.75,1.375and0.938,and Elite respectively chose1.375and0.984,and tube voltage was120kV,and auto tube current was30-250mA,and NI was14,and rotation speed of ST-16and Elite were respectively were0.8sand0.5s.(4)rotation speed of two models of PET-CT respectively chose0.5s,0.8s and1.0s,and tube voltage chose120kV,andauto tube current chose30-250mA,and NI was14,and pitches of ST-16and Elite respectively were1.75and0.984.The aboveconditions were respectively was applied to scan anthropomorphic phantom(Model RS-550)through simulated step-scanmethod of clinical PET-CT,and then the dose-length product(DLP)under different conditions were recorded and the effectivedose(EDCT)was calculated.Result:1)When the automatic tube current,Pitch and rotation speed were unchanged,the effectivedoses caused by CT part of the both of two models of PET-CTs were decreased with the increasing of NI,and the decreasingamplitude of ST-16was larger than that of Elite.2)When the NI,
作者
吴一田
耿建华
杜召猛
毕高畅
齐雍鹤
张朝坤
郑容
吴宁
WU Yi-tian;GENG Jian-hua;DU Zhao-meng(Department of PET-CT Center and Nuclear Medicine, National Cancer Center/Cancer Hospital,Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021,China)
出处
《中国医学装备》
2017年第10期13-18,共6页
China Medical Equipment
基金
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"
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"
关键词
正电子发射断层扫描
体层摄影术
自动管电流
有效剂量
CT
Positron emission tomography
Body section radiography
Automatic tube current
Effective dose
CT
