How 3D printing is revolutionizing medicine: The use of 3-D printing at many medical centers is still in its infancy, but the technology is already revolutionizing medicine. For example, physicians have used 3-D printing to:Plan liver resection. More than 20 liver models to date have been at built to improve surgical planning and training. Models are made from a flexible resin with internal lumen geometry generated from a reconstructed CT scan.