To create a 'complete' mental image of the patients structures, the radiologist has to take all available slices into account. 3D Medical visualization can help to overcome this problem by providing the user with a 3D representation of the patients anatomy reconstructed from the set of image slices. Two examples for the application of medical visualization are discussed in the following sections. Virtual Endoscopy Virtual endoscopy is an application which deals with the exploration of hollow organs and anatomical cavities using volume data. Using a real endoscope is always painful or at least inconvenient for the patient.
Virtual endoscopy is used as a non-invasive diagnostic technique.
It may also be applied in surgical planning, training and exploration of structures not reachable with a real endoscope. The common approach for the visualization of a virtual endoscopy is surface rendering, yielding images close to a real endoscopy. If external structures are of interest, volume rendering techniques have to be used. These methods do not display the exact shape of the inner lumen very well. For certain applications, eg operation planning of a transbronchial biopsy, both, the shape of the inner lumen as well as outer structures like blood vessels and the tumor have to be delineated.