Salivary gland ultrasonography: a highly specific tool for the early diagnosis of primary Sjögren’s syndrome
The main SGUS feature distinguishing Primary Sjogren Syndrome from other causes of dry mouth is the homogeneity on grey scale ultrasound: the more hypoechoic areas and linear hyperechoic lesions, the more likely it's PSS. Its specificity is superior to the Schirmer's test. In fact, the sensitivity, specificity, and the positive & negative predictive values approximate that of the invasive Minor Salivary Gland Biopsy. As such, it may be a viable substitute to the latter in a future revision of the recently published ACR-EULAR Sjogren classification criteria.