Figure 5.

Examples of the convolutional neural network (CNN) codes and the corresponding absolute difference from a pair of lesion‐present/absent images, at the 26th convolutional layer of ResNet‐50. The inset computed tomography (CT) images (70 × 70 pixels) illustrate a pair of lesion‐present/absent examples from condition #1, and the arrow indicates the lesion location. These CNN codes corresponded to six randomly selected feature channels at the corresponding network layer. The images at each column correspond to the same convolutional filter channel. The display window of the difference images was narrowed down ([0, 0.4]) for the convenience of illustration.