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

Objective. To explore the performance of sonoelastography (SE) in diagnosis and clinical evaluation of primary Sjogren'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 cutoff 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). Conclusion. 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.