Application of computed tomography-based radiomics in differential diagnosis of adenocarcinoma and squamous cell carcinoma at the esophagogastric junction

Table 2 Model optimism estimation by 1000-times bootstrap in the training group

Index	Model	Apparent AUC1	AUC Bootstrap-test2 (mean, 95%CI)	Optimism
1	2D-arterial model	0.808	0.770 (0.767-0.772)	0.050
2	2D-venous model	0.849	0.820 (0.817-0.822)	0.036
3	3D-arterial model	0.876	0.815 (0.812-0.880)	0.080
4	3D-venous model	0.877	0.833 (0.830-0.835)	0.056

¹The area under the curve of predictive model developed in the whole training dataset.

²The averaged model performance in the “out-of-bag” test set after 1000-times bootstrap. AUC: Area under the curve.