I have tried with 3D slicer, Simvascular softwares but failed to get a solid geomtery model..Rather I achieved a Meshed surface with number of small parts. How can I create a solid geometry model which can be saved in STEP/STP format?
You can try by converting dicom to stl files initially in 3D slicer, and then stl to step/stp file using Solidworks or CAD Exchanger. I hope this is what you need.