1. A method of processing computed tomography (CT) data for an object in a region comprising: identifying a plurality of volume elements associated with the region, each volume element being associated with a density value; for each volume element of interest, (i) identifying a plurality of neighboring volume elements of the region, (ii) comparing the density value associated with each of the neighboring volume elements with a predetermined object density range, (iii) classifying neighboring volume elements whose density values are within the predetermined object density range as object volume elements, (iv) counting a number of object volume elements in the neighboring volume elements, (v) comparing the number of object volume elements with a predetermined threshold, (vi) if the number of object volume elements does not exceed the predetermined threshold, classifying the volume element of interest as an exterior surface volume element to distinguish the volume element of interest from interior surface volume elements, and (vii) defining an object as including a subset of the volume elements associated with the region, said subset of volume elements including interior surface volume elements and excluding exterior surface volume elements.