Performance of salivary glands ultrasonography, shear wave elastography and their combined use for the diagnosis of primary and secondary Sjögren's syndrome.

Abstract

Sjögren's syndrome (SS) is a common rheumatic disease for which finding the right imaging tool remains a challenge. This study aimed to evaluate the performance of salivary gland ultrasonography (SGUS), shear wave elastography (SWE) and their combined use for the diagnosis of primary and secondary SS (pSS and sSS). This retrospective study included patients with dry symptoms who underwent routine examinations between May 2019 and December 2023. Patients were categorized into the pSS (n=41), sSS (n=26), and control (n=27) groups based on the American College of Rheumatology/European League Against Rheumatism classification criteria (2016). A comparison of SGUS and shear wave velocity (SWV) results was conducted among the three groups. The diagnostic capabilities of different ultrasound methods for SS were evaluated using receiver operating characteristic (ROC) curves and the area under the curve (AUC) for specificity. Compared to the control group, both the pSS (1.80±1.03vs. 0.67±0.48, p<0.001) and the sSS (1.85±0.88vs. 0.67±0.48, p<0.001) groups exhibited significantly elevated SGUS scores. However, there was no statistically significant difference between the pSS and sSS groups (p=0.849). The SWV values in both the pSS and sSS groups were significantly higher than those in the control group (all p<0.001). The AUC for diagnosing SS using only SGUS scores was 0.823 (95% confidence interval [CI]: 0.731-0.894). Combining SGUS scores and SWV values resulted in improved diagnostic accuracy (AUC: 0.883, 95% CI: 0.801-0.940). SGUS and SWE are pivotal in the diagnosis of Sjögren's syndrome, with their synergistic application poised to bolster diagnostic precision. This combined approach also furnishes substantial backing for the clinical assessment and management of Sjögren's syndrome.