MRI sialographyIf the infection of a salivary gland does not prompt the patient to see a doctor, the patient or the dentist may notice a solid mass in the base of the mouth. It is essential that this is examined by an expert, as it could also be a tumour. The doctor will arrange for an ultrasound investigation (sonography) to be carried out to make an initial diagnosis. A sialogram can be carried out to show the system of ducts or a stone. For this, a contrast agent is injected into the excretory duct. This spreads out in the ductal system and then shows up on the x-ray image. This makes it easier to asses changes to the calibre or obstacles, whether the problem is a stone or stenosis of the duct. If there is also suspicion of a chronic disease of the salivary glands, further examination methods such as an MRI scan can be used for accurate diagnosis.

These methods, however, can only detect stones with a diameter of more than 2mm. The endoscopic inspection of the ductal system, on the other hand, shows even very small stones, and they can be clearly differentiated from strictures and small polyps.