TotalSegmentator V2 sub-task (v2.5.0-weights, Apache-2.0). 4 fg classes:
lung_airways, lung_airways_wall, lung_arteries
(intra-pulmonary PA tree), lung_veins (intra-pulmonary PV tree).
Fills the gap left by the main total model, which labels only
the pulmonary trunk + 4 hilum vein stumps and treats lung-internal vessels
as parenchyma. Patch [96,160,160] @ [1.0, 0.703, 0.703] mm, cubic B-spline
resample, NibabelIOWithReorient → SAR, CTNormalization (mean=-302.1,
std=412.8). PlainConvUNet 6-stage with anisotropic last stride [1,2,2].
Trainer nnUNetTrainerSkeletonRecall (training-time loss only — inference
forward path identical to vanilla PlainConvUNet).