@Juicy @manjula thanks for the great suggestions. It is awesome to see that you’ve learnt so much about Slicer and now helping others, too! Well done.
I particularly like recommendatiom of “Grow from seeds” here, as it effectively learns the intensity range dynamically instead of trying to apply some predefined textbook values (which do not work very well, especially for soft tissues).
Pre-creating segments with fixed intensity ranges can be useful, too, at least to have a general idea about how well the different tissue types are separable with simple global thresholding.