辐射剂量对第二代双层探测器光谱CT碘定量和单能量图像CT值准确性的影响  

Effects of different radiation doses on the accuracy of quantitative iodine concentration and CT value of virtual monochromatic image in second-generation dual-layer detector spectral CT

作　　者：吴巧玲 田均平[1] 张大明[1] 金征宇[1] 陆晓梅 于胜会 王沄[1] WU Qiaoling;TIAN Junping;ZHANG Daming;JIN Zhengyu;LU Xiaomei;YU Shenghui;WANG Yun(Department of Radiology,Peking Union Medical College Hospital,CAMS&PUMC,Beijing 100730;Department of Clinical Science,Philips Health Science and Technology Limited Company,Beijing 100600,China)

机构地区：[1]中国医学科学院北京协和医学院北京协和医院放射科,北京100730 [2]飞利浦健康科技有限公司临床科研部,北京100600

出　　处：《基础医学与临床》2023年第12期1866-1870,共5页Basic and Clinical Medicine

摘　　要：目的用多能谱CT碘定量体模,探讨不同辐射剂量对第二代双层探测器光谱CT碘定量和单能量图像CT值准确性的影响。方法用第二代双层探测器光谱CT扫描腹部碘体模,模型包含3种不同浓度的碘棒,分别为4、8和12 g/L。扫描参数分别设置为100、120和140 kVp 3组管电压,每组管电压下分别扫描6个辐射剂量序列:5、10、15、20、25和30 mGy。测量所有碘棒的碘浓度值及在单能级50、70和100 keV下的CT值,计算不同辐射剂量下碘浓度的绝对误差值和CT值的绝对误差值。用SPSS 22.0软件单因素方差分析分别比较不同辐射剂量下碘浓度和CT值绝对误差的差异,用LSD法做组间两两比较。结果100 keV能级下10~30 mGy辐射剂量扫描4 g/L碘棒CT值测量绝对误差显著高于12和8 g/L(P<0.05),其余不同浓度碘棒在不同辐射剂量下碘浓度测量绝对误差均无差异。结论第二代双层探测器光谱CT在辐射剂量大于5 mGy的条件下对碘定量及CT值准确性的测量稳定性均较高。Objective To investigate the effect of different radiation doses on the accuracy of iodine quantification and CT value of virtual monochromatic image with a muti-spectral CT iodine phantom using second-generation dual-layer detector spectral CT(DLCT).Methods The second-generation DLCT scan abdominal phantom was used,which consisted of six different concentrations of iodine rods at 4,8 and 12 g/L.The scan parameters were set at 100,120 and 140 kVp tube voltages,and six radiation exposure sequences were scanned at each tube voltage:5,10,15,20,25 and 30 mGy.Measure the iodine concentration value and the CT value at the single level of 50,70 and 100 keV,and calculate the absolute error value of iodine concentration and CT value under different radiation exposure.SPSS 22.0 software single factor analysis of variance was used to compare the difference between the iodine concentration and the absolute error of CT value under different Radiation exposure,and LSD method was used to compare the two groups.Results The absolute error of CT value of 4 g/L iodine rod with 10~30 mGy scanning at 100 keV energy level was significantly higher than that of 12 g/L and 8 g/L(P<0.05),and the absolute error of iodine concentration measurement of other iodine rods with different concentrations at different Radiation exposure had no statistical difference.Conclusions The second-generation double-layer detector spectral CT has high measurement stability for iodine concentration quantification and CT value accuracy under conditions of radiation dose greater than 5 mGy.

关 键 词：光谱CT 碘定量 辐射剂量 

分 类 号：R814.42[医药卫生—影像医学与核医学]