1. A method for extracting a three-dimensional (3D) volume of interest from a three-dimensional (3D) image dataset, said method comprising: accessing a 3D image dataset that includes a plurality of image slices; enclosing a 3D volume of interest in the 3D image dataset using a 3D mesh, wherein the 3D mesh comprises a plurality of polygons; projecting the polygons onto two-dimensional (2D) planes; identifying, for each polygon, a set of 2D grid points that are bounded by the respective polygon; automatically extracting the 3D volume of interest based on the 3D mesh; and generating a 3D image of the extracted 3D volume of interest.