Figure 4. CT images obtained from multiplanar reformatting of a volume of interest containing a 9-mm polyp (arrow). A-C, Transverse, coronal, and sagittal sections, respectively, of a volume of interest extracted from an isotropic volume set. D-F, Transverse, coronal, and sagittal sections, respectively, of the segmented colon obtained in the same volume of interest as in A-C. Voxels that have shape index values corresponding to the cap, saddle or ridge, and rut or cup shapes are green, pink, and brown, respectively. As expected, a substantial portion of the polyp is green, whereas folds and colonic walls are pink and brown, respectively.