How to get spatial coordinate information of an anatomical structure?

[yiyang]

Hello,

I am using a script to place electric dipoles within specific structures in an anatomical model, such as the gastrointestinal (GI) tract (including the stomach, small intestine, etc.). The question is, how can I get the coordinates of the space occupied by the model of the GI tract, or in other words, how can I verify that the electric dipoles I place are inside the tissue of the GI tract? Thanks for your help!