Just how well are your salivary glands working? A salivary scan can tell you. This noninvasive nuclear medicine test looks at the parotid and submandibular glands—found below the ears, on the sides of the neck—using a gamma scintillation camera and radioactive tracer called technetium 99.
Based on the tracer’s uptake and secretion, a doctor can determine if dry mouth (xerostomia) is caused by a growth in the salivary gland, Sjögren’s syndrome or a blocked salivary duct. A salivary scan can also be used to detect if salivary gland swelling is due to inflammation, infection (abscess) or obstruction from a pocket of fluid (cyst). In cases involving a growth in the parotid gland, the test differentiates between a benign Warthin’s tumor and a cancerous one.
But how does a salivary gland scan work? A small amount of tracer is first injected in one of the veins on your arm. The camera then scans for radiation from the tracer as it flows through your blood and into the salivary gland. And every few minutes, it takes pictures showing how much of the tracer accumulates in the glands.
About 45 minutes later, you may be given a lemon drop (or anything that’s just as sour) to stimulate the release of saliva. Additional images are captured, for comparison with the initial batch of pictures. The whole procedure lasts an hour or so.
A nuclear medicine specialist or radiologist examines the images, usually providing results within two days. On the whole, a salivary scan is generally painless and safe. It is, however, not recommended for women who are pregnant as the radiation might harm the fetus. Those who are breastfeeding may have to switch to formula for one or two days before resuming nursing.