1. A method for virtual endoscopy in a lumen, comprising: acquiring from a patient an imaging dataset including a lesion external to a lumen wall; generating multiplanar reformations (MPRs) from said dataset; drawing planar contours around said lesions in said MPRs; deriving a three-dimensional (3-D) volume of said lesion from said contours; determining distances from a reference point to the start and end of said lesion; determining the distance from said reference point to a virtual endoscope in said lumen; obtaining data on maximum bend characteristics for a said endoscope in a lumen of a given diameter; deriving projection criteria, based on said 3-D volume, the lumen diameter, and said maximum bend characteristics; projecting an endoluminal image of said lesion based on said projection criteria, said endoluminal image indicating an optimal biopsy insertion point; and deriving corrected values for the foregoing distances allowing for said maximum bend characteristics.