The introduction of spiral (helical) computed tomography (CT) has revolutionized the way established body CT examination are performed and has created new examinations as CT angiography. The production of overlapping images from single short X-ray exposure, the minimization of motion artefact and the suppression of respiratory misregistration have all improved performance of routine CT examinations. These same technical advantages have also led to the development of new applications. With advanced 3-D postprocessing applications, simulated endoscopy is made possible permitting the radiologist the view anatomy from within any lumen or anatomic space within the body.