Clinical Utility of Diffusion-weighted Whole-body Magnetic Resonance Imaging with Background Body Signal Suppression for Assessing and Monitoring IgG4-related Disease.

A 77-year-old man with symptoms of chest pain was diagnosed with immunoglobulin G4 (IgG4)-related disease. Fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) revealed an intense uptake in the submandibular gland, lymph nodes and abdominal aortic wall. Diffusion-weighted imaging with background body signal suppression (DWIBS) revealed signal enhancements at the same location as those of the FDG-PET/CT findings. The DWIBS signal intensity decreased after steroid treatment, so we decreased the steroid dosage. Relapse did not occur. DWIBS makes it possible to adjust the medicine dosage while confirming the therapeutic effects and will likely be a useful method for monitoring IgG4-related disease.