2 Summary Rese rch 8 And the Average Surface Distance (ASD) defined as: ( , ̂ ) = 1 2 ( 1 ∑min ( ( , ̂ )) + 1 ̂ ∑min ( ( ̂ , )) ̂ ) For experiment 1, part A of the figure below shows that results of the first block of iW-Net (in red) become more similar to the inter-observer agreement (in yellow) when there is an increase of nodule radius, and both follow the same trend in the Average IoU, underlining a general difficulty in segmentation of the smaller nodules. Experiment 2 manages to improve the baseline segmentation on 78% of the cases and the respective Average absolute IoU increases of 0.08 ± 0.10. The improvement is evident in the remaining graphs where we can see the average IoU (graph B) and ASD (graph D) per nodule texture in the three cases: segmentations from 1 st block of iW-Net (red), corrected segmentations from total iW-Net (green) and inter-observer agreement (yellow). Again, we can see that all types of segmentations are worse with sub-solid and non-solid nodules, as expected, and the difference between methods is higher for non-solid cases. Finally, part C shows the Average absolute IoU improvement between the initial and the corrected segmentation using iW-Net per nodule radius. This demonstrates that this method mostly advances the quality of segmentation when the nodules lie in the range between 1-4mm.