Fig. 1

Representative examples of magnetic resonance (MR) lesions: a Wall thickness > 3 mm: coronal T2-weighted images with fat saturation of the descending colon (a) and terminal ileum (b); coronal T2-weighted images of the descending colon (c) and terminal ileum (d) (arrow in image). b Mural edema (high signal intensity on T2 sequences with fat saturation compared with normal appearing loops): coronal T2-weighted images with fat saturation (a) and without (b) of the terminal ileum from the same patient show high signal intensity. Coronal (c) and axial (d) T2-weighted images with fat saturation of the descending colon from the same patient (arrow in image). c Fat stranding (loss of the normal sharp interface between the intestinal wall and mesentery, with edema/fluid in the perienteric fat): coronal T2-weighted images with fat saturation of the descending colon (a), and ascending colon (b, c) (arrow in image). d Mucosal ulceration: coronal T2-weighted images with fat saturation of the ascending colon (a, c) and descending colon (b) (arrow in image)