Relationship of MR imaging of submandibular glands to hyposalivation in Sjögren's syndrome

Objective: We analysed the correlation between magnetic resonance images of the parotid and submandibular glands and the salivary flow rate in patients with Sjögren's syndrome. Methods: We retrospectively reviewed magnetic resonance images (heterogeneous signal-intensity distribution and gland volume on T1- and fat-suppressed T2-weighted images, and multiple high-signal-intensity spots on magnetic resonance sialograms in the parotid and submandibular glands) obtained from 66 patients who were diagnosed with Sjögren's syndrome. We evaluated the relationship between these imaging features and their salivary flow rates in stimulated and unstimulated conditions. Results: We found that as the disease progressed, both the heterogeneous signal-intensity distribution and the volumes of the parotid and the submandibular glands were significantly related to the stimulated and the unstimulated salivary flow rate. These imaging features were more highly correlated in assessments of the submandibular gland than in those of the parotid gland for both stimulated and unstimulated salivary flow rates. Conclusions: Magnetic resonance image features of heterogeneity and smaller volume in the submandibular gland are reliable for predicting hyposalivation related to the progression of Sjögren's syndrome.