摘要目的:探讨CT重建算法、辐射剂量和对比剂3种参数对纯磨玻璃密度肺结节影像组学特征稳定性的影响。方法:前瞻性选取2018年于中国医学科学院肿瘤医院就诊的35例肺结节患者(50枚纯磨玻璃密度肺结节)，对同一患者肺结节的原始图像重建后共获得6种不同参数的序列，使用ITK－SNAP软件分别对不同序列的纯磨玻璃密度肺结节进行分割，将所有扫描数据通过美国GE公司的A.K.软件进行肺结节影像组学特征提取，通过组内相关系数选取复测信度好的影像组学特征，使用R语言统计学软件对特征参数进行分析，将不同序列的所有特征值配对比较，分别统计改变采集和重建参数导致变化的影像组学特征的数量，比较不同采集和重建参数对纯磨玻璃密度肺结节影像组学特征稳定性的影响。采用配对样本 t检验或Wilcoxon检验比较不同序列特征值分布的差异，采用 χ2检验比较改变不同参数后发生变化的影像组学特征数量的差异。 结果:50枚纯磨玻璃密度肺结节共提取391个影像组学特征，组内相关系数>0.75的特征为320个。同时改变CT重建算法、辐射剂量和对比剂3种参数时，发生变化的纯磨玻璃密度肺结节影像组学特征达到60.9%(195/320)，其中包括6.7%(1/15)的形态学特征、100.0%(40/40)的直方图特征和58.1%(154/265)的纹理特征。仅改变1种参数(保持其他2种参数不变)的情况下，分别改变CT重建算法、辐射剂量和对比剂，发生变化的纯磨玻璃密度肺结节影像组学特征分别为10.6%(34/320)、30.9%(99/320)和50.6%(162/320)，差异有统计学意义(均 P<0.05)。当辐射剂量和对比剂改变时，与50%自适应迭代重建技术(ASiR－V)比较，滤波反投影(FBP)重建算法获得的影像组学特征发生变化更小( P＝0.001)。 结论:CT重建算法、辐射剂量和对比剂会影响纯磨玻璃密度肺结节的影像组学特征，其中对比剂对纯磨玻璃密度肺结节影像组学特征的影响最大，辐射剂量次之，CT重建算法最小；与形态学特征比较，直方图特征和纹理特征容易受到CT重建算法、辐射剂量和对比剂的影响；与50% ASiR－V比较，FBP重建算法获得的影像组学特征受辐射剂量与对比剂的影响更小，在影像组学分析中应充分考虑到这些参数的影响。

abstractsObjective:To investigate the influence of CT reconstruction algorithm, radiation dose, and contrast agent on the stability of radiomic features of pure ground-glass density pulmonary nodules.Methods:A total of 50 pure ground-glass density pulmonary nodules in 35 patients were prospectively selected from Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College in 2018. After reconstructing the original image of the same patient′s pulmonary nodules, six sequences of different parameters were obtained. ITK-SNAP software was used to segment different sequences of pure ground-glass density pulmonary nodules. All scanning data were extracted by A. K. software. The radiomic features with good retest reliability were selected by the intraclass correlation coefficient. The statistical software of R language was used to analyze the characteristic parameters. All the radiomic feature values of different sequences were paired and compared. The number of radiomic features changed by acquisition and reconstruction parameters was counted. The influence of different parameters on the reproducibility of pure ground-glass density pulmonary nodules was compared.Results:A total of 391 radiomic features were extracted from 50 cases of pure ground-glass density pulmonary nodules. 320 features with an intraclass correlation coefficient greater than 0.75 were selected for further analysis. By changing the three parameters of CT reconstruction algorithm, radiation dose, and contrast agent simultaneously, the changed radiomic features of the pure ground-glass density pulmonary nodules reach 60.9% (195/320), including 6.7% (1/15) morphological feature, 100.0% (40/40) histogram features, and 58.1% (154/265) texture features. When only one parameter was changed (keeping the other two parameters unchanged), changing the CT reconstruction algorithm, radiation dose, and contrast agent respectively, the changed radiomic features of pure ground-glass density pulmonary nodules were 10.6% (34/320), 30.9% (99/320) and 50.6% (162/320), the difference was statistically significant ( P<0.05). When the radiation dose and contrast agent were changed, the radiomic features obtained by the FBP reconstruction algorithm had smaller changes than the features obtained by the 50% ASiR-V algorithm ( P=0.001). Conclusions:CT reconstruction algorithm, radiation dose, and contrast agent will affect the radiomic features of pure ground-glass density pulmonary nodules. The contrast agent has the most significant influence on the radiomic features, followed by radiation dose and CT reconstruction algorithm minimum. Compared with morphological features, histogram features and texture features are more likely to be affected by CT reconstruction algorithms, radiation doses, and contrast agents. Compared with the 50% ASiR-V algorithm, the radiomic features obtained by the FBP reconstruction algorithm are less affected by the radiation dose and contrast agent. The influence of these parameters should be fully considered in the radiomic analysis.