Diagnostic value of major salivary gland ultrasonography in primary Sjögren's syndrome: The role of grey-scale and colour/ power Doppler sonography

Primary Sjögren's syndrome (pSS) is an autoimmune connective tissue disease characterized primarily by chronic inflammatory involvement of the exocrine glands, particularly the salivary glands. The use of ultrasound in the study of salivary glands (SGUS) has expanded considerably in recent years. The ultrasound can document structural alterations that can be visualized as hyperechogenic and hypoechogenic areas, or as areas with non-homogeneous echogenicity. To date, several systems of SGUS scoring systems of abnormalities during pSS are available. From the studies published in recent decades, it has been possible to document the high sensitivity and specificity of the pathological findings that can be documented by SGUS. SGUS can also provide added value in identifying patients at risk for developing disease complications such as lymphoma. The Doppler technique can also supply information about glandular tissue vascularization, which is very useful for diagnostic and differential purposes. In this review we will present the state of the art of SGUS, with a prevailing focus on diagnostic use and possible future developments.