摘要
目的:探讨低剂量螺旋CT对肺部结节灶扫描的最佳条件及其应用价值,并评价低剂量与常规剂量螺旋CT扫描的X线放射剂量比。方法:对75例88个肺内结节分别用200mA、40mA、30mA、20mA和10mA进行螺旋CT扫描。测量结节的最大径、CT值、最大CT值,记录结节的各种内部征象、噪声和伪影及每次扫描的单次CT剂量加权指数(CTDIw)及mA。结果:5种不同管电流扫描图像所示肺内结节灶的检出率、最大径、CT值及结节的各种内部征象,各组间差异无统计学意义(P>0.05),噪声和伪影10mA组高于其它组(P<0.05),200mA常规剂量组与低剂量各组比较CTDIw值差异有显著性意义(P<0.05)。结论:20mA是肺部扫描的最佳剂量,具有辐射量小、敏感性强、性价比高的特点,值得推广应用。
Objective:The purpose of this study is to investigate scanning parameters of low dose spiral CT in evaluation of pulmonary nodules and to evaluate low dose helical CT in chest compared with conventional dose helical CT.Methods:Eighty-eight pulmonary nodules of seventy-five patients underwent spiral CT scan with 200mA,40mA,30mA,20mA and 10mA respectively.The diameter,CT value and the highest CT value were measured.The different signs of the nodules were analyzed.So did the excessive noise and artifact of images.The weighted CT dose index (CTDIw) and milliampere seconds (mAs) were recorded.Results:There was no significant difference between the five groups in detection,diameter,CT value and all the signs within the nodules (P>0.05).Noise and artifact of images in 10mAs group were higher than other groups (P<0.05).There was significant difference about the data of the CTDIw between the conventional helical CT group and the other groups (40mA,30mA,20mA,10mA)(P<0.05).Conclusion:20mA is the most appropriate milliampere for lung scanning.With the lower radiation and the higher sensitivity and the better price performance ratio,low-dose spiral CT is worthy to be used widely.
出处
《放射学实践》
2005年第7期604-608,共5页
Radiologic Practice
