MRT Diagnostik bei Morbus Crohn

The role of magnetic resonance imaging in the diagnoses of crohns disease has recently expanded but it is still not routinely used. The purpose of this study is to determine the usefulness of MR enteroclysis in the diagnosis of crohns disease. Therefore we evaluated the sensitivity, specificity, positive and negative likelihood ratio to assess crohns disease inflammatory activity and typical complications. From July 2004 to January 2007 83 Patients with known or suspected chronic inflammatory bowl disease underwent an MR enteroclysis study. We compared the findings of these studies with findings of other explorations and information from patient records. According to our results MR enteroclysis is, with a sensitivity of 97%, a specificity of 87%, a positive likelihood ratio of 7,45 and a negative of 0,03 in patients with crohns disease, preeminently suitable for assessing crohns disease inflammatory activity. The lack of radiation exposure and the possibility to generate reproducible pictures and images of extraluminal inflammatory manifestations are advantages over conventional methods as CT, ultrasound and endoscopy. MR enteroklysis is less useful for detecting intestinal stenosis. In patients with crohns disease we found a sensitivity of 86%, a specificity of 77%, a positive likelihood ratio of 3,67 and a negative of 0,19. MR enteroclysis has difficulties especially in detecting low grade stenosis. This problem also appears in other imaging techniques and may be overcome by a better distention of the small bowel. For the detection of fistulas our MR protocol is not suitable because it did not include a MR imaging of the small pelvis, where most of the false negative results were found. Therefore we found a sensitivity of only 57%, a specificity of 95%, a positive likelihood ratio of 10,68 und a negative of 0,45. Good results for showing fistulas and their surrounding anatomic structures may be expected when MR enteroclysma is combined with MR imaging of the small pelvis. MR imaging is therefore able to show a holistic picture of localization and extend of crohns disease and it may be expected that it will become more accepted in clinical routine and may be appointed as a „ONE-STOP-SHOP-Technique“ in the diagnosis of crohns disease.