ABSTRACT
During the past few decades, the use of cross-sectional imaging modalities for the noninvasive evaluation of lower gastrointestinal tract has signicantly increased due to improvements in diagnostic technique and the dissemination of computed tomography (CT) and magnetic resonance (MR) scanners. CT is still the modality of choice for the assessment of acute colonic inammation, for the evaluation of metastatic disease from colorectal malignancy, and for colorectal cancer screening; in each case, CT colonography (CTC) provides an excellent evaluation of the inner colonic surface. Because of superior acquisition speed, increased spatial resolution, and superior image quality robustness, multislice CT
appears to be more suitable for colorectal cancer screening than MR. However, MR colonography (MRC) can be a good alternative to noninvasive investigation of the colon, especially in young patients, because of the absence of ionizing radiation.
