Ultrasonography of salivary glands -- a highly specific imaging procedure for diagnosis of Sjögren's syndrome.

OBJECTIVE

To verify ultrasonographic criteria for examination of the major salivary glands in diagnosis of primary and secondary Sjögren's syndrome (SS).

METHODS

Three hundred sixteen consecutive patients with rheumatic diseases were selected according to the European Consensus Study Group diagnostic criteria for SS. Fifty-seven had primary SS, 33 had secondary SS, 78 had Sicca symptoms, and 148 patients served as asymptomatic controls. This cohort was analyzed for size and parenchymal echogenicity of the major salivary glands by ultrasonography.

RESULTS

Evident parenchymal inhomogenicity in 2 or more major salivary glands was detected by ultrasonography in patients with primary and secondary SS with a sensitivity of 63.1% and 63.6%, respectively. The specificity of this imaging approach in our cohort was 98.7%. The volume of submandibular glands was reduced in patients with primary and secondary SS by about 30% compared to patients with sicca symptoms and asymptomatic controls. In receiver-operating characteristic (ROC) curve analysis, the detection of reduced volumes of both submandibular glands in patients with primary and secondary SS had a specificity of 93% and a sensitivity of 48% at the cutoff point of 3.0 ml. Of note, the volume of the parotid glands did not differ between the groups of patients. In patients with primary SS, parenchymal inhomogenicity of the salivary glands was strongly associated with positivity for anti-Ro and/or anti-La antibodies.

CONCLUSION

Ultrasonographic detection of parenchymal inhomogenicity of the major salivary glands and observation of reduced volume of the submandibular glands resulted in high specificities for diagnosis of primary and secondary SS. The data indicate that ultrasonography of major salivary glands is a noninvasive imaging procedure with high diagnostic value for the diagnosis of primary and secondary SS.