1. A method for generating an image, said method comprising: accessing data of a scan of an object; using at least one characteristic of the accessed data to delineate at least one item of interest in the data; and generating a 3D visualization image wherein transparency levels for at least some pixels not representing the item of interest are set according to a first set of rules, and transparency levels for at least some pixels representing an interior portion of the item of interest are set according to a second set of rules different than the first set of rules, and at least some pixels representative of a transition area are set according to a third set of rules different than the first and second sets of rules.