Background: The reproducibility of radiomics features extracted from CT and MRI examinations depends on several physiological and technical factors. The aim was to evaluate the impact of contrast agent timing on the stability of radiomics features using dynamic contrast-enhanced perfusion CT (dceCT) or MRI (dceMRI) in prostate and lung cancers. Methods: Radiomics features were extracted from dceCT or dceMRI images in patients with biopsy-proven peripheral prostate cancer (pzPC) or biopsy-proven non-small cell lung cancer (NSCLC), respectively. Features that showed significant differences between contrast phases were identified using linear mixed models. An L2-penalized logistic regression classifier was used to predict class labels for pzPC and unaffected prostate regions-of-interest (ROIs). Results: Nine pzPC and 28 NSCLC patients, who were imaged with dceCT and/or dceMRI, were included in this study. After normalizing for individual enhancement patterns by defining seven individual phases based on a reference vessel, 19, 467 and 128 out of 1204 CT features showed significant temporal dynamics in healthy prostate parenchyma, prostate tumors and lung tumors, respectively. CT radiomics-based classification accuracy of healthy and tumor ROIs was highly dependent on contrast agent phase. For dceMRI, 899 and 1027 out of 1118 features were significantly dependent on time after contrast agent injection for prostate and lung tumors. Conclusions: CT and MRI radiomics features in both prostate and lung tumors are significantly affected by interindividual differences in contrast agent dynamics.
背景：从CT和MRI检查中提取的影像组学特征的可重复性受多种生理和技术因素影响。本研究旨在评估动态对比增强灌注CT（dceCT）或MRI（dceMRI）中对比剂注射时机对前列腺癌和肺癌影像组学特征稳定性的影响。方法：分别从经活检证实的外周带前列腺癌（pzPC）患者和经活检证实的非小细胞肺癌（NSCLC）患者的dceCT或dceMRI图像中提取影像组学特征。通过线性混合模型识别不同对比剂时相间存在显著差异的特征，并采用L2惩罚逻辑回归分类器预测pzPC与未受累前列腺感兴趣区域（ROI）的类别标签。结果：本研究纳入9例pzPC患者和28例NSCLC患者，均接受dceCT和/或dceMRI检查。通过参考血管定义七个个体化时相对个体强化模式进行标准化后，在1204个CT特征中，分别有19个（健康前列腺实质）、467个（前列腺肿瘤）和128个（肺肿瘤）特征呈现显著的时间动态变化。基于CT影像组学的健康与肿瘤ROI分类准确度高度依赖对比剂时相。在dceMRI的1118个特征中，分别有899个（前列腺肿瘤）和1027个（肺肿瘤）特征与对比剂注射后时间显著相关。结论：前列腺癌和肺癌的CT与MRI影像组学特征均显著受对比剂动力学个体间差异的影响。
Contrast Agent Dynamics Determine Radiomics Profiles in Oncologic Imaging
肿瘤(癌症)患者之家