Advances in imaging of obstructed salivary glands can improve diagnostic outcomes

Obstruction of the major salivary glands is a relatively common condition defined as the blockage of the salivary outflow in the glandular ductal system. It can however mimic more aggressive pathology.

The most common cause of salivary obstruction is sialolithiasis, followed by ductal strictures. Salivary obstruction is clinically characterized by a food-related painful swelling of the affected gland, known as 'mealtime syndrome'.

When obstruction is clinically suspected, the role of imaging consists of confirming the obstruction, identifying its cause, evaluating the position and extent of the obstruction and evaluating for associated complications. However, if imaging shows up signs of a tumour or other pathology which can mimic an obstructed gland clinically instead, the radiologist can alert the clinician accordingly to change the course and plan of treatment. Several imaging techniques are available for investigating the obstructed salivary glands.

This review looks at the causes of obstruction and the use, diagnostic performance and practicality of the various imaging modalities. Importantly, an imaging approach algorithm for the evaluation of the obstructed salivary gland is also proposed.