目的 探讨低X线剂量及低碘含量 对比剂及迭代重建技术CT扫描应用于早 期肺癌检出的可行性。方法 选取2014年 1月至2016年12月行胸部CT平扫及增强扫 描96例早期肺癌患者。所有患者采用完 全随机分组法平均分为常规剂量组(常规 辐射剂量+造影剂用量1.5ml/Kg)和双低 剂量组(低辐射剂量+造影剂用量1.0ml/ Kg)，造影剂浓度为270mg/100ml。比较 不同组别之间的诊断率、CT值、信噪比 (SNR)、对比噪声比(CNR)、图像噪声标 准差(SD值)、评分值，以及造影剂量、 剂量容积CT剂量指数、剂量长度乘积、 有效剂量。结果 两实验组的诊断率、CT 值、信噪比(SNR)、对比噪声比(CNR)、 图像噪声标准差(SD值)、评分值之间无 统计学差异(P>0.05)，造影剂量、有 效剂量之间有统计学差异(t=13.451、 P><0.05;t=32.248、P<0.05)。结论 双低 剂量CT扫描及迭代重建技术能够得到满意 的早期肺癌扫描图像，对于早期肺癌的筛 查有很大的临床意义。

Objective To discusses the feasibility of CT scanning of low-x and low iodine content in early lung cancer. Methods Collected January 2014 to December 2016, the chest CT scan was performed and 96 patients were screened for lung cancer. Grouping all of the patients using completely randomly divided into routine dose group (regular doses of radiation and dosage of contrast agent 1.5 ml/Kg) and double low dose group (low doses of radiation and dosage of contrast agent 1.0 ml/Kg), contrast medium concentration of 270mg/100 ml. Comparison between different groups of diagnosis, CT value, signalto-noise ratio (SNR), contrast to noise ratio (CNR), image noise standard deviation (SD), score values, as well as imaging dose and dose volume CT dose index, the length of the product, effective dose. Results Two experimental diagnosis, CT value, signal-to-noise ratio (SNR), contrast to noise ratio (CNR), image noise standard deviation (SD), score values between no statistical difference (P>0.05), angiography was statistically difference between dose and effective dose (t=13.451, P><0.05, t=0.05, P<0.05). Conclusion Double low-dose CT scans and iterative reconstruction techniques were able to obtain satisfactory early lung cancer scans, which had significant clinical implications for early lung cancer screening.