1. A method for computer-assisted stenting, including stent planning, comprising the steps of: acquiring image data from an internal region of a subject comprising a lumen afflicted with a lesion and reconstructing an at least 3D image of said region from said image data, said 3D image containing and representing characteristics of said lesion; conducting a stenosis analysis of said lesion characteristics using said 3D image with at least a portion of said stenosis analysis being automatically electronically conducted by computerized analysis of said lesion characteristics, to obtain a stenosis analysis result; based on said stenosis analysis result, selecting an actual stent to treat said lesion; in a computer, generating a virtual simulated stent corresponding to said actual stent; electronically overlaying said virtual stent on said 3D image and, in a computer, automatically electronically determining a best position of said virtual stent, relative to said lesion, for effectively treating said lesion as well as automatically electronically determining an angulation of a C-arm of an imaging system that will be used during a stenting procedure to implant said actual stent; and conducting said stenting procedure to implant said actual stent, including generating a real time 2D image of said internal region using said imaging system with said C-arm thereof at said angulation, and including said virtual stent at said best position in said real time 2D image, and manually guiding said actual stent in said stenting procedure using said real time 2D image to bring said actual stent to an actual position in said internal region coinciding with said best position.