Perspective volume rendering of CT and MR images: Applications for endoscopic imaging

PURPOSE: To use perspective volume rendering (PVR) of computed tomographic (CT) and magnetic resonance (MR) imaging data sets to simulate endoscopic views of human organ systems. MATERIALS AND METHODS: Perspective views of helical CT and MR images were reconstructed from the data, and tissues were classified by assigning color and opacity based on their CT attenuation or MR signal intensity. 'Flight paths' were constructed through anatomic regions by defining key views along a spline path. Twelve movies of the thoracic aorta (n = 3), tracheobronchial tree (n = 4), colon (n = 3), paranasal sinuses (n = 1), and shoulder joint (n = 1) were generated to display images along the flight path. All abnormal results were confirmed at surgery. RESULTS: PVR fly-through enabled evaluation of the full range of tissue densities, signal intensities, and their three-dimensional spatial relationships. CONCLUSION: PVR is a novel way to present volumetric data and may enable noninvasive diagnostic endoscopy and provide an alternate method to analyze volumetric imaging data for primary diagnosis.