The CT image is processed by the 3D FCN using a tiling strategy (sliding-window) (Çiçek et al., 2016) as illustrated in Fig. 5. For greater speed, we use non-overlapping tiles in the first stage and investigate the use of non-overlapping and overlapping tiles in the second. When usingoverlapping tiles (with a 4× higher sampling rate of each voxel x), the resulting probabilities for the overlapping voxels are averaged: