Assessment of lacrimal gland involvement in primary Sjögren's syndrome using gray-scale ultrasonography and shear wave elastography.

OBJECTIVES: The aim of this study was to assess lacrimal gland involvement in primary Sjögren's syndrome (pSS) using lacrimal gland gray-scale ultrasound (LGUS) and two-dimensional shear wave elastography (2D-SWE).

METHODS: Eighty-five pSS patients with a mean age of 51.16 ± 10.61 years and 84 sex- and age-matched healthy subjects with a mean age of 50.94 ± 11.05 years were included in the study. Lacrimal gland parenchymal findings and 2D-SWE values were compared between the two groups and the correlations of LGUS parameters with clinical findings, dry eye tests, and minor salivary gland biopsy (MSGB) were further investigated.

RESULTS: LGUS parenchymal grade was 0 in 14 (16.5%), 1 in 45 (52.9%), 2 in 23 (27.1%), and 3 in 3 patients (3.5%) in the pSS group, while in the control group, parenchymal grades were 0 (57.1%) and 1 (42.9%). The mean 2D-SWE value of pSS patients was significantly higher than the control group (p < 0.05) and increased parallel with lacrimal parenchymal grade. The elasticity modulus had a high diagnostic performance in detecting lacrimal gland involvement in pSS patients (AUC 0.901, sensitivity 70.6%, specificity 97.6%), while the diagnostic performance of LGUS was much lower (AUC 0.769, sensitivity 83.5%, specificity 57.1%). LGUS and 2D-SWE values were found to be correlated with dry eye tests and MSGB results (p < 0.05).

CONCLUSIONS: LGUS and 2D-SWE are both useful for assessing the lacrimal gland involvement in pSS patients; however, 2D-SWE has a better diagnostic performance than LGUS and found to be correlated with dry eye tests.

CLINICAL RELEVANCE STATEMENT: Lacrimal gland US and two-dimensional shear wave elastography (2D-SWE) are imaging modalities that can be used to demonstrate parenchymal involvement of the lacrimal gland in primary Sjögren's syndrome (pSS).

KEY POINTS: • Gray-scale US and two-dimensional shear wave elastography (2D-SWE) have been widely used in the recent decade to assess gland involvement in patients with primary Sjögren's syndrome (pSS). • The elasticity modulus had a high diagnostic performance in detecting lacrimal gland involvement in primary Sjögren's syndrome (pSS) patients. • Lacrimal gland US and two-dimensional shear wave elastography (2D-SWE) are both useful for assessing the lacrimal gland in primary Sjögren's syndrome (pSS) patients; however, two-dimensional shear wave elastography (2D-SWE) has a better diagnostic performance than lacrimal gland ultrasound (LGUS).