1. A method for reconstructing a three-dimensional image of a region of interest of an object disposed within an object region from cone beam projection data, the method comprising the steps of: a) acquiring the cone beam projection data, the cone beam projection data comprising a plurality of cone beam projection images; b) identifying a region of interest within each of two projection images; c) projecting each identified region of interest through at least a portion of the object region to identify a three-dimensional reconstruction region defined by a plurality of points; and d) reconstructing the image at each of the plurality of points to form the three-dimensional image of the region of interest.