Hello, I’m trying to expand isotropically a ROI using grow/shrink. The problem is my voxel size is anisotropic [0.9,0.9,2.5] and I want to do a 2 mm expansion which is not possible using slicer segment editor (as shown in the image) . Also I want understand how this growing of ROIs work in 3D Slicer
You can decrease the spacing of the segmentation if your current spacing is comparable or larger than the desired margin. Setting a 0.9mm isotropic spacing could make sense (that would allow exactly 1.8mm expansion), but if you want exact 2.0mm growth then you have to resample to something like 1.0mm or 0.5mm.