The diagnostic value of shear-wave elastography in the salivary glands of patients with primary Sjögren syndrome.

Abstract

We aimed to quantify the extent of salivary gland fibrosis using shear-wave elastography (SWE) to assess its diagnostic value for primary Sjögren syndrome (pSS). A total of 58 pSS patients and 44 controls underwent SWE ultrasound evaluation of the parotid and submandibular glands. We measured the degree of salivary gland fibrosis in all participants and investigated the diagnostic accuracy of SWE for pSS and its relationship to disease progression. The diagnostic sensitivity, specificity, and accuracy of pSS were highest when the critical Young's modulus values of the parotid and submandibular glands were 18.4 and 15.9 kPa, respectively, effectively improving the diagnostic value of pSS. The area under the SWE curve of the submandibular gland was higher than that of the parotid gland (z = 2.292, P = 0.02), suggesting that the submandibular gland was damaged earlier. The mean parotid gland thickness of pSS patients was thicker than in healthy controls (mean ± standard deviation 2.5 ± 0.3 vs 2.4 ± 0.2, P = 0.013]. SWE had a 70.3% sensitivity for diagnosing pSS patients with a disease duration of 5 years, but this did not differ significantly from pSS patients with a longer disease duration. SWE is a valid diagnostic method for pSS. The degree of salivary gland fibrosis related to secretory function and pathological progression, and quantitative measurements of tissue elasticity provide objective criteria for predicting damage in pSS.