超低剂量CT在婴儿胸部检查中的临床应用  

The clinical application of ultra-low dose CT in infants chest examination

作　　者：张静[1,2] 闫锐 郭银霞 杜永浩[1] 牛刚[1] ZHANG Jing;YAN Rui;GUO Yinxia;DU Yonghao;NIU Gang(Department of Radiology,the First Affiliated Hospital of Xi’an Jiaotong University,Xi’an 710061,China;Medical Imaging Center,Northwest Women’s and Children’s Hospital,Xi’an 710061,China)

机构地区：[1]西安交通大学第一附属医院医学影像科,陕西西安710061 [2]西北妇女儿童医院医学影像中心,陕西西安710061

出　　处：《实用放射学杂志》2020年第6期969-972,共4页Journal of Practical Radiology

摘　　要：目的探讨超低剂量CT在婴儿胸部检查中的临床应用。方法前瞻性连续选取0~12个月临床拟诊支气管炎或支气管肺炎行胸部CT平扫检查婴儿90例,随机分为3组,每组各30例。A组:常规电压固定管电流(100 kV,75 mA);B组:常规电压自动管电流(100 kV,40~100 mA);C组:低电压自动管电流(80 kV,40~100 mA),其余扫描参数均相同。所有图像采用5分制评分进行主观图像质量评价;然后基于python,导入主动脉弓、隆突和下肺静脉相应层面的轴位图像进行客观图像质量评价,包括图像像素平均值,灰度标准差,平均梯度,熵。最后记录各组的CT剂量指数(CTDIvol)、剂量长度乘积(DLP),并估算有效剂量(ED)(ED=DLP×k)。采用单因素方差分析评价各组间图像质量及辐射剂量。结果3组婴儿主观图像质量评价统计均无显著性差异;各组客观图像质量评价组间的熵统计有显著性差异(P=0.046),其余客观指标图像像素平均值,灰度标准差及平均梯度各组间均无显著性差异;ED:A组[(2.65±0.30)mSV]>B组[(1.67±0.21)mSV]>C组[(0.90±0.24)mSV],各组间统计学有显著性差异。结论婴儿胸部超低剂量CT检查,应用80 kV低电压联合自动管电流调节(ATCM)技术,在保证图像质量的情况下可显著降低辐射剂量。Objective To investigate the clinical application of ultra-low dose CT in infants chest examination.Methods 90 infants aged 0 to 12 months were underwent chest CT scan for suspected bronchitis or bronchopneumonia,they were randomly divided into three groups with 30 infants in each group respectively.Group A were performed with conventional kVp and constant mA(100 kV,75 mA),group B with conventional kVp and automatic tube current modulation(100 kV,40-100 mA)and group C with lower kVp and automatic tube current modulation(80 kV,40-100 mA),and the remaining parameters were the same.Subj ective image quality was evaluated by 5-point scoring system for all images.Moreover,based on python algorithm,axial images of aortic arch,protuberance and inferior pulmonary vein level were imported for obj ective quality evaluation,including image pixel mean,gray-scale standard deviation,average gradient and entropy.Finally,the CT dose index volume(CTDIvol),dose length product(DLP)of each group were recorded and the effective dose(ED)(ED=DLP×k)was estimated.Single factor analysis of variance was used to evaluate the image quality and radiation dose between each group.Results There was no significant difference in subj ective image quality evaluation statistics among the three groups.The entropy statistics of obj ective image quality evaluation groups showed significant differences(P=0.046),while the pixel mean,gray-csale standard deviation and average gradient showed no significant differences among the groups.ED:group A[(2.65±0.30)mSV]>group B[(1.67±0.21)mSV]>group C[(0.90±0.24)mSV],there were statistically significant differences between groups.Conclusion 80 kV low-kilovoltage combined with automatic tube current modulation(ATCM)technique for ultra-low dose CT scanning of infant chest can significantly reduce the radiation dose under the condition of ensuring image quality.

关 键 词：低电压 自动管电流调节 婴儿胸部 超低剂量 计算机体层成像 

分 类 号：R814.49[医药卫生—影像医学与核医学] R72[医药卫生—放射医学]