this is a short answer to a question with a long answe.
1. this topic is discussed in the vodcasts so tke a listen
2. radiologists were trained ina axial CTs and most workstations are designed for a 2D read
3. 3D is critical for staging and surgical planning
4. 3D is critical in apps like virtual colonoscopy , cardiac CT and Ct angiography
5. access to 3D has been limited but is increasing
6. poor payments limits growyh