Table 3.

Performance metrics for the CNN model versus skilled radiologists

Performance metric	Internal	External (based on ROI)	External (based on patients)	R1	R2
Accuracy, %	89.5	79.3	82.5	55.8	55.4
Sensitivity	0.88	0.83	0.75	0.71	0.73
Specificity	0.87	0.67	0.86	0.51	0.5
PPV*	0.71	0.55	0.69	0.29	0.29
NPVǂ	0.95	0.90	0.89	0.86	0.86
F1 score	0.77	0.63	0.72	0.41	0.42
Kappa	0.69	0.48	0.59	0.15	0.15
Youden index	0.75	0.50	0.61	0.22	0.23

*Positive predictive value; ^ǂNegative predictive value