Table 1. Parameters used in our experiments.

Modality	Parameters and values	Comments
MRI	d f = 64	Dimension of computed features for each sampled image patch
	Patch size: 16 × 20 × 20 Voxels	Patch size used for localization of VB centers at the coarse step
	Patch size: 8 × 40 × 40 Voxels	Patch size used for localization of VB centers at the fine-tuning step
CT	d f = 128	Dimension of computed features for each sampled image patch
	Patch size: 20 × 20 × 12 Voxels	Patch size used for localization of VB centers at the coarse step
	Patch size: 80 × 80 × 32 Voxels	Patch size used for localization of VB centers at the fine-tuning step
For both modalities	Patch size: 8 × 8 × 8 Voxels	Patch size used for VB segmentation
	N = 15000	Number of sampled training image patches for localization, at both coarse and fine-tuning steps
	N′ = 10000	Number of test image patches, both in coarse and fine-tuning steps
	M = 12000	Number of training image patches for segmentation
	W j = 1	See Eq (2)
	h = 1.5	See Eq (2)
	α = 0.4	See Eq (7)
	β = 0.6	See Eq (7)