Correlation between salivary gland ultrasonography and scintigraphy in primary Sjögren's syndrome

Abstract

Objective: To compare findings on salivary gland ultrasonography (SGUS) and salivary gland scintigraphy (SGS) in patients with primary SS (pSS).

Methods: The study cohort included patients newly diagnosed with pSS who underwent SGUS and SGS at the same time at our tertiary care hospital. Baseline demographics, laboratory data, clinical data and SGUS and SGS findings were collected. An SGUS cut-off score ≥14 defined positive SGUS findings and was used to classify patients in SGUS+ and SGUS- groups. SGS findings were quantified by the parotid:submandibular uptake ratio (PU:SU) and percentage parotid/submandibular excretion (%PE/%SE). The correlation between SGUS and SGS findings was evaluated.

Results: For analysis, 18 patients with SGUS+ findings and 18 with SGUS- findings were recruited, for a total study cohort of 36 patients. There were no between-group differences in baseline demographics and clinical and laboratory data. The PU, %PE, SU and %SE were significantly lower in the SGUS+vs SGUS- group. The SGUS score for the parotid gland was negatively correlated to the PU (r = -0.36, P = 0.03) and %PE (r = -0.35, P = 0.04). The SGUS score of the submandibular gland was negatively correlated to the SU (r = -0.42, P = 0.01) and %SE (r = -0.39, P = 0.02).

Conclusions: Patients with a higher SGUS score had lower salivary gland function. The SGUS score showed a significant correlation with PU, %PE, SU and %SE. These findings are indicative of a possible predictive role of SGUS to diagnose salivary gland dysfunction.

Keywords: primary Sjögren’s syndrome; salivary gland scintigraphy; salivary gland ultrasonography.