The value of magnetic resonance enterography in diagnostic difficulties associated with Crohn's disease.

PURPOSE: The diagnosis of Crohn's disease (CD), one of the inflammatory bowel diseases (IBD), along with ulcerative colitis (UC), is often challenging due to the limitations of small intestine visualisation. Magnetic resonance enterography (MRE) enables imaging of intraluminal and extraintestinal complications without ionizing radiation. The objective of this study is to select CD-related MRE features and determine the feasibility of this technique to indicate a group of patients that should be subjected to more invasive diagnostic procedures. MATERIAL AND METHODS: A total of 131 patients (mean age 25) underwent MRE, 60 of whom had been previously diagnosed with CD and 17 with UC. Additionally, 26 patients with suspected IBD and 28 with other or unknown pathologies were included in the study. Radiological reports of MRE examinations, effectuated using a 1.5-T field strength, were retrospectively analysed regarding radiological features of IBD, such as the following: bowel wall thickening, enhancement, comb sign, stricture, enlarged mesenteric nodes, inflammatory infiltration, and abnormal diffusion restriction in diffusion-weighted imaging. The statistical model was based on machine learning of the Kohonen map, together with univariate and multivariate analysis. RESULTS: The selected neuron (Neuron 3) incorporated 23 cases of CD, 9 of suspected IBD, 2 patients with UC, and 4 with other pathologies. The statistical analysis identified bowel wall thickening, intestinal stricture, and lymphadenopathy as the 3 MRE findings most associated with Neuron 3 (AUC = 0.919, p = 0.031). CONCLUSIONS: Bowel wall thickening, stricture, and enlarged mesenteric lymph nodes in MRE are independent predictive factors for CD diagnosis; thus, patients presenting these features should undergo further examinations. MRE constitutes a powerful imaging modality in cases of suspected IBD.

Up-to-date overview of imaging techniques in the diagnosis and management of inflammatory bowel diseases.

Radiological examination occupies a significant role, complementary to endoscopic studies, in the diagnostic process of inflammatory bowel disease (IBD). Both ulcerative colitis and Crohn's disease, due to multiple remissions and relapses, require repetitive examinations to evaluate the disease extent, severity, and response to pharmacological treatment. Whereas the use of barium contrast studies is progressively reduced, plain radiography confirms its utility as a first-line imaging tool for acute abdomen. Computed tomography remains an easily accessible and effective method to demonstrate disease activity and extraintestinal manifestations. However, the related radiation exposure reduces its applicability to urgent situations. Ultrasound and magnetic resonance, with the great advantage of avoiding ionising radiation, are highly recommended to present the complications of IBD. Use of oral and intravenous contrast in computed tomography enterography and magnetic resonance enterography demonstrates IBD involvement in the small intestine wall, which is difficult to assess in other radiological and endoscopic examinations.