Sonoelastography of salivary glands for diagnosis and clinical evaluation in primary Sjögren's syndrome.

OBJECTIVES: To explore the performance of sonoelastography (SE) in diagnosis and clinical evaluation of primary Sjögren's syndrome (pSS). METHODS: SE examination of major salivary glands was conducted for 79 pSS patients, 39 disease controls and 15 healthy subjects. Elastographic images were determined with a qualitative 4-point scoring method. Receiver operating characteristic (ROC) curve was employed to evaluate the performance of the elasticity scoring method and the best cut-off value was determined. The associations between elasticity scores and disease characteristics were analysed to evaluate the clinical value of SE for pSS. RESULTS: Elasticity scores of parotid and submandibular glands in pSS group were significantly higher than those in the non-pSS group (p<0.001). The sum of the scores of all four glands provided the largest AUC-ROC (0.916, 95% CI 0.87-0.962), compared with that of bilateral parotid glands (0.857, 95% CI 0.794-0.919) and that of bilateral submandibular glands (0.783, 95% CI 0.704-0.863). The optimal cut-off value was 9 for combined evaluation of all four glands (81% sensitivity and 87% specificity, respectively). The elasticity scores of parotid glands in patients with disease duration >10 years experienced significant difference as compared to patients with disease duration ≤5 years and 5-10 years respectively (p=0.007, 0.009, respectively), whereas it presented no variations between the disease duration ≤5 years and 5-10 years (p=0.952). CONCLUSIONS: Sonoelastography, performed simultaneously with ultrasonography, is an additional tool for the assessment of the salivary glands in patients with pSS. The elasticity is closely associated with disease duration.