Imaging of Sjögren Syndrome and Immunoglobulin G4-Related Disease of the Salivary Glands.

The salivary glands are commonly affected in systemic autoimmune disease and diseases of unknown pathogenesis. Sjögren syndrome (SjS) can be affected by other systemic diseases. Immunoglobulin G4-related disease (IgG4-RD) commonly affects salivary glands. Imaging findings are usually nonspecific; however, radiologists should be familiar with the manifestations to avoid diagnostic delay. Findings of early-stage SjS are difficult to identify on routine computed tomography or MR imaging. Chronic SjS can be diagnosed from MR imaging and sialographic findings. Multiglandular and localized involvement of IgG4-RD is difficult to differentiate from malignant lymphoma for multiglandular disease and salivary gland carcinoma for localized disease.