螺旋CT低剂量胸部扫描技术在儿童气管病变中的应用

Clinical study on the influence of helical CT at low-dose chest scaning in airway post processing images of children

目的评价螺旋CT低剂量胸部扫描技术在儿童气管病变的应用价值。方法150例疑有气管病变的儿童,用3组不同的管电流(40、80、180mA)行螺旋CT胸部扫描。记录单次加权CT剂量指数(weighted CTdose index,CTDIw)、扫描长度,计算出平均剂量长度乘积(dose-length produce,DLP)。由专家对不同扫描参数的气管后处理所显示的病变与支气管镜检结果进行比较,按Ⅰ、Ⅱ和Ⅲ级图像等级评判图像质量,并进行统计学处理。结果40、80mA的CTDIw及DLP与180mA的比值分别为20·5%、41·0%。各组可符合临床诊断要求的后处理图像差异无统计学意义。40和80mA扫描诊断的准确性分别为98·3%、100%。结论螺旋CT低剂量胸部扫描不影响小儿气管图像后处理效果,可清楚显示病变,适用于儿童气管疾病的检查。

Objective To evaluate the value of helical CT at low-dose chest seaning in post processing images of children airway. Methods CT chest scaning with three different tube current of 180 mA, 80 mA and 40 mA was accomplished to 150 children suspected airway lesions. Weighted CT dose index （CTDIw）each time and scanning length were recorded during scanning and then average of dose length product（DLP） was calculated. Comparison between lesions displayed by airway post processing and the results of fiberoptic bronchoscopy was completed at different scanning parameters of three groups by experts, and the quality of each image was judged according to Ⅰ , Ⅱ and Ⅲ image level and then statistical analysis was performed. Results The CTDIw with tube current of 40 mA and 80 mA equaled to 20.5% and 41% of that with 180 mA. There wasn＇t statistically significance between post processing images meeting clinic diagnostic requirements with 40 mA, 80 mA and 180 mA. The displaying accuracy of airway lesions by post processing images with tube current of 40 mA and 80 mA was 98.3% and 100%, respectively. Conclusion Helical CT low-dose chest scaning, which has no effect on the post processing images of children airway and may display the lesions clearly, is applicable to children＇s airway diseases.