1. A method for detecting anomalous pulmonary nodules, the method comprising: obtaining a two-dimensional (2D) feature model of a pulmonary nodule; segmenting the pulmonary nodule by performing vector quantification to expand the 2D feature model to a three-dimensional (3D) model; and displaying, on a display, image information representing whether the pulmonary nodule is benign, based upon the 3D model expanded from the 2D feature model.