Hi all, I have a DICOM file of the whole human heart and chest. I need to: 1- extract part of the geometry, say the aortic root, from the whole geometry; 2- convert it to an STL format file. Anyone can please suggest (free) software (Windows and Mac) for the foregoing purposes? I am searching the internet I could find a variety of them though I am willing to hear your generous suggestions as well. Thank you!