Computed tomographic colonography (CTC) is a potential alternative to other full structural screening examinations used to detect colonic neoplasia. It refers to the acquisition and interpretation of the volumetric dataset of the colon using helical CT and is performed after air or carbon dioxide enema. Although initial results appear promising, patient preparation, CT acquisition parameters, and methods of data analysis continue to differ from institution to institution. For CTC to succeed as a costeffective alternative to screening colonoscopy and double-contrast barium enema, it will need to have a high accuracy for colonic lesions of significant size and a high degree of patient compliance at reasonable cost [1].