Fig. 4From: A cycle generative adversarial network for improving the quality of four-dimensional cone-beam computed tomography imagesa 4D-MSCT, b 4D-CBCT, and c synthetic 4D-CBCT (sCT) images of the same patients in the corresponding axial, coronal, and sagittal directions. All images are shown with the same window width and levels. d Two-dimensional histograms of the axial direction in each image. The height of each histogram represents the count for the CT numberBack to article page