The display of three-dimensional anatomy with stereolithographic models

Stereolithography, a new technique of prototype fabrication developed for the aerospace industry, offers a unique way to display patient anatomy. Like current computer aided design (CAD) systems, it uses digital image data from computed tomography (CT) and magnetic resonance (MR) to produce a physical model. Unlike conventional CAD it does not require a cutting tool and, therefore, CAD toolpath limitations do not exist. The stereolithography apparatus uses an ultraviolet laser to selectively polymerize and solidify a polymeric liquid plastic solution under computer control. The device was used to produce a model of cranial bony anatomy from CT image data, providing full internal detail in the constructed model, including encased sinuses, foramen, and potentially complete internal anatomy within a closed skull. The advantages and disadvantages of this technology are reviewed with an emphasis on future development.