Since the introduction of Computed Tomographic Colonography (CTC), research has mainly focused on visualization and navigation techniques. Recently, efforts have shifted towards computer aided detection (CAD) of polyps. We propose a new approach to CAD in CT images that attempts to model the way a radiologist recognizes a polyp using optical flow fields (OFF). Features extracted from OFFs are used by a linear classifier for polyp detection. An initial validation of our technique resulted in an average of 75% specificity at 100% sensitivity in a 10-fold cross validation study on a set of 220 polyp-like structures, 20 of which were true polyps.