To assess the diagnostic value of salivary gland ultrasonography (SGUS) for primary SS (pSS) and to compare the usefulness of two existing SGUS scoring systems.
Ultrasonography examination of major salivary glands was conducted for 105 pSS patients and 41 disease control subjects without SS and 16 healthy control subjects. The imaging features were graded using two different scoring systems (0-16 and 0-48, respectively) obtained from the grades of bilateral parotid and submandibular glands. Receiver operating characteristic curves were used to describe and compare the diagnostic accuracy of the two ultrasonography echostructure scoring systems for pSS. The agreement of diagnosis for pSS between the two scoring systems was determined by κ-statistics.
SGUS scores for the pSS group were significantly higher than those for the non-pSS group (P < 0.001). The best score cut-off was 7 in the 0-16 system (80% sensitivity and 93% specificity, respectively), and it was 15 in the 0-48 system (88.6% sensitivity and 84.2% specificity, respectively). Compared with the 0-16 system, combined evaluation of all four glands when using the 0-48 system improved the diagnostic accuracy. Association analysis of both scoring systems showed a positive correlation of SGUS scores with RF and γ-globulin% (P < 0.05, overall).
SGUS is a feasible method for pSS diagnosis with higher sensitivity using the 0-48 system and better specificity using the 0-16 system. SGUS scores are related to RF and γ-globulin%.