CT扫描中非标准定位像对图像质量和辐射剂量影响的模体研究  

Phantom Study on the Impact of Non-Standard Localizer Radiograph on Image Quality and Radiation Dose in CT Scanning

作　　者：卞红丽 胡梅[1] 孙小磊[2] 陈骥梁 张久楼 徐露露[1] BIAN Hongli;HU Mei;SUN Xiaolei;CHEN Jiliang;ZHANG Jiulou;XU Lulu(Department of Radiology,The First Affiliated Hospital with Nanjing Medical University,Nanjing Jiangsu 210029,China;Department of Clinical Engineering,The First Affiliated Hospital with Nanjing Medical University,Nanjing Jiangsu 210029,China;Siemens Healthineers Digital Technology(Shanghai)Co.,Ltd.,Shanghai 200000,China)

机构地区：[1]南京医科大学第一附属医院放射科,江苏南京210029 [2]南京医科大学第一附属医院临床工程处,江苏南京210029 [3]西门子数字医疗科技(上海)有限公司,上海200000

出　　处：《中国医疗设备》2024年第8期20-24,共5页China Medical Devices

基　　金：国家自然科学基金(62101278)。

摘　　要：目的通过模体实验探讨非标准定位像对螺旋CT扫描图像质量和辐射剂量的影响。方法利用包含模体的标准定位像扫描模体并获得基线组图像,利用包含模体、注射器的非标准定位像扫描模体并获得非基线组图像。比较2组图像的质量参数:噪声、CT值线性(3种材料:特氟隆,聚乙烯,空气)、密度分辨率和空间分辨率;比较2组扫描协议中的剂量相关参数:有效毫安秒(Effective Milliampere Seconds,eff.mAs)、CT容积剂量指数(CT Dose Index Volume,CTDIvol)。结果噪声方面,基线组显示低于非基线组(P<0.05);CT值线性方面,基线组较非基线组更接近标准CT值(P<0.05);密度分辨率方面,基线组可识别的最小孔阵直径显著小于非基线组(P<0.05);2组空间分辨率比较差异无统计学意义(P>0.05);eff.mAs和CTDIvol在2组扫描协议的比较中,非基线组均高于基线组(P值均<0.05)。结论螺旋CT扫描中标准定位像的使用可以较低辐射剂量来满足图像质量要求;非标准定位像的使用既提高了辐射剂量,也损害了图像质量。Objective To investigate the impact of non-standard localizer radiographs on the image quality and radiation dose of spiral CT scans through phantom experiments.Methods A standard localizer radiograph including the phantom was utilized for scanning the phantom and obtaining baseline group images,followed by a non-standard localizer radiograph containing the phantom and syringe to scan the phantom for non-baseline group images.The quality parameters of the two groups of images were compared including noise,linear CT value(3 materials:Teflon,LDPE,Air),density resolution and spatial resolution.Additionally,dose-related parameters between the two scanning protocols including effective milliampere seconds(eff.mAs)and CT dose index volume(CTDIvol)were compared.Results The comparison of noise in baseline group was lower than that in non-baseline group(P<0.05).Regarding CT value linearity,the baseline group showed a closer alignment to the standard CT value than the non-baseline group(P<0.05).In terms of density resolution,the baseline group significantly outperformed the non-baseline group in identifying the smallest diameter of the hole array(P<0.05).The difference was not statistically significant in spatial resolution between the two image groups(P>0.05).In the comparison of scanning protocols between the two groups,the eff.mAs and CTDIvol were higher in the non-baseline group than in the baseline group(all P<0.05).Conclusion Using standard localizer radiographs in spiral CT scans can achieve image quality requirements with lower radiation doses.The use of non-standard positioning images not only increases the radiation dose,but also damages the image quality.

关 键 词：螺旋CT扫描 模体成像 图像质量 辐射剂量 

分 类 号：R197.39[医药卫生—卫生事业管理] R816[医药卫生—公共卫生与预防医学]