Usefulness of MR imaging of the parotid glands in patients with secondary Sjögren's syndrome associated with rheumatoid arthritis

Abstract

Objective. To assess the correlation between MR imaging (MRI) of parotid glands with X-ray sialography, histopathology of the labial salivary glands, and salivary secretion, in patients with secondary Sjögren's syndrome (SS) associated with rheumatoid arthritis (RA).

Methods. Non-contrast MRI of the parotid glands was performed in 13 secondary SS patients associated with RA who satisfied the revised Japanese diagnostic criteria for SS (1999), and the ACR/EULAR classification criteria for RA (2010). The MRI findings were classified according to the degree of high-intensity signal on T1-weighted images (T1WI) and short inversion time inversion recovery (STIR) images into five grades (0–4), using the modified Nagasaki University grading method. The results of MRI grading were compared with the Rubin and Holt staging of X-ray sialography (0–4), the Greenspan grading of labial salivary gland histopathology (0–4), and salivary secretion by the gum test (ml/10 min).

Results. All 13 patients were females, with a mean age of 50.2 ± 11.3 years. According to the MRI grading, 3 patients were Grade 1, 5 were Grade 2, 5 were Grade 3, and none was Grade 0 or Grade 4. The mean stage by X-ray sialography was 1.7 ± 1.0, the mean grade by histopathology was 2.4 ± 1.2, and the mean volume of salivary secretion was 9.7 ± 3.9 ml. The MRI grading correlated significantly with the Rubin and Holt staging and Greenspan grading (P < 0.01 each, Spearman's rank correlation), and significantly and inversely with the results of the gum test (P < 0.05).

Conclusion. The results suggest that MRI of the parotid glands is a useful noninvasive tool for evaluating destruction and inflammation in the salivary glands.

Keywords:

• MR imaging
• Parotid glands
• Sjögren's syndrome
• Rheumatoid arthritis

Acknowledgments

We thank Dr. F. G. Issa for the critical reading of the manuscript. This work was supported in part by the Health and Labour Sciences Research Grants for research on intractable diseases from the Ministry of Health, Labour and Welfare of Japan, and Grants-in-Aid for Scientific Research (Grant-in-Aid for Young Scientists (B)) from the Ministry of Education, Culture, Sports, Science and Technology and Japan Society for the Promotion of Science.

Conflict of interest

None.