Using Optical Flow Fields for Polyp Detection in Virtual Colonoscopy

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.