What is salivary gland scintigraphy used for, and how is it performed?
A salivary gland study is used to evaluate patients with suspected abnormalities in salivary gland function (e.g., with Sjögren’s disease) or with salivary gland tumors. The scan does not require a specific patient preparation. Typically, 5 to 10 mCi of 99m Tc pertechnetate is injected intravenously while obtaining scans for approximately 25 to 30 minutes (usually in 5-minute increments). This allows for maximum radiotracer uptake by the salivary glands. There is often some spontaneous salivary discharge, but the second part of the study (the washout phase) usually involves giving the patient a lemon drop to induce salivary flow while images continue to be obtained for another 15 to 20 minutes. Lateral projections of the salivary glands are also obtained immediately prior to the washout phase. This methodology allows for an evaluation of overall radiotracer uptake (i.e., normal or reduced), presence of any focal defects (e.g., due to a tumor), and of radiotracer washout (i.e., normal versus obstructed).
Here is the list some causes of bilaterally decreased salivary gland radiotracer uptake.
Some Causes of Bilaterally Decreased Radiotracer Uptake on Salivary Gland Scintigraphy
- • Sjögren’s syndrome
- • Sialoadenitis following radiation therapy
- • Acute suppurative parotitis
- • Obstructive sialolithiasis
- • Sialoadenitis