Abstract: A method of formatting data for identifying colon polyps in a Computed Tomography Colonography (CTC) dataset comprising the steps of: extracting colon surface data, from the CTC dataset, within a sub-volume centered on a candidate polyp (CP) seed point; identifying individual sets of points corresponding to the CP's body and CP's base within the sub-volume; selecting the points corresponding to the body; re-formatting the candidate polyp by projecting the selected points corresponding to the body on to a tangent plane; and generating a series of cutting planes based on the reformatted candidate polyp.

Abstract: A method of processing a 3-dimensional Computed Tomography Colonography data set to remove tagged material is disclosed. The method involves the preliminary processing step of classifying voxels in the data set as corresponding to air, tagged material or colon tissue. Methods of overcoming erroneous classification of Partial Volume air/tagged material interface voxels are disclosed. The present invention also provides for methods of circumventing problems resulting from removal of tagged material from a CTC data set, which can result in the erosion of soft-tissue structures partially covered by tagged colonic fluid.

Abstract: A method of formatting data for detecting flat polyps in a Computed Tomography Colonography, CTC, dataset comprising the steps of: extracting colon surface data, from the CTC dataset, within a sub-volume centred on a candidate polyp seed point; identifying individual sets of points corresponding to the candidate polyp's body and the candidate polyp's base within that sub-volume; projecting the set of points corresponding to the candidate polyp's body on to a tangent plane via a normal vector, wherein the normal vector is calculated from the best fitting plane to the set of points corresponding to the candidate polyp's base; isolating a new seed point for the candidate polyp from the projected data; locating the nearest surface point to the new seed in the extracted dataset above, and region-growing the surface ab initio from this point; identifying individual sets of points corresponding to the candidate polyp's body and the candidate polyp's base in the region-grown surface, and determining the normal vector