Ultrasound of the salivary glands in Sjögren's syndrome: a narrative review of its diagnostic and prognostic utility and clinical role.

Sjögren's Disease (SjD) is a systemic autoimmune disease whose classification criteria include a minor salivary gland biopsy (MSGB), an invasive procedure. Salivary gland ultrasound (SGUS) has emerged as a non-invasive, accessible and reliable tool for the evaluation of SjD. This narrative review analyses the evolution of SGUS, from the first scoring systems to the current consensus of the OMERACT group, which has enabled standardisation of the evaluation. The evidence on the diagnostic accuracy of SGUS, its correlation with MSGB and autoantibodies, and its ability to predict patient classification according to the 2016 ACR/EULAR criteria are analysed. In selected patients, SGUS may reduce the need for minor salivary gland biopsy, particularly in those positive for anti-Ro/SSA antibodies. In addition, it explores its potential role in prognostic stratification, lymphoma prediction, and treatment response monitoring, proposing an algorithm for its integration into daily clinical practice.