Fig. 4: The ROC curves of the DDCHD-DenseNet and confusion matrix for screening for duct-dependent CHDs in prospective datasets and two external datasets with three levels of sonographer performance (junior-most, junior, and senior) to compare.

In the confusion matrix, the horizontal coordinate is the predicted label, and the vertical coordinate is the true label. The distribution of predict scores related to the duct-dependent CHD determined by the Transfer Learning Group and the General Group in retrospective datasets.