Figure 3: 29-year-old woman with CD. (a) Axial T2-weighted FS image demonstrating thickened wall of a long small bowel segment. (b), (c) There is increased enhancement and restricted diffusion of the involved small bowel mucosa seen on axial contrast enhanced T1-weighted and DWI images, respectively. (d) Axial PET attenuation correction image demonstrating FDG uptake along the involved small bowel segments. (e) Axial fused T2-weighted FS PET/MR image demonstrating FDG uptake correlating with thickened small bowel wall. (f) Coronal PET attenuation correction image showing increased FDG uptake in the terminal ileum (arrow) and several small bowel segments. Colonoscopy revealed terminal ileitis that was further confirmed by histology. However, colonoscopy did not reflect the true extent of disease as seen on 18F-FDG PET/MR.