Sialography

Sialography or radiosialography is the radiographic examination of the salivary glands. It usually involves the injection of a small amount of contrast medium into the salivary ducts of a single gland, followed by routine X-ray projections.

Indications

Since the advent of contrast CT, sialography and ultrasonography are rarely indicated in the investigation of the patient who has parotid disease. Sialography is helpful in suspected cases of ductal stricture, calculi or sialectasia.

Procedure

The test is performed in a hospital radiology department or in the health care provider's office by an X-ray technician. You may be given a sedative before the procedure.

You will be asked to lie on your back on the X-ray table. An X-ray is taken before the contrast material is injected to ensure that no stones are present to stop the contrast material from entering the ducts. A catheter (a small flexible tube) will be inserted through your mouth and into the duct of the salivary gland. A contrast medium in then injected into the duct so that the duct will show up on the X-ray. X-rays will be taken from a number of positions.

You may be given lemon juice by mouth to help stimulate the production of saliva. Pictures are repeated to examine the drainage of the saliva into the mouth.

Interpretation

The salivary gland striated ductal epithelium can extract Tc99m (pertechnetate) from the capillary network of the salivary glands. The presence of a hot mass is usually indicative of Warthin's tumour or oncocytoma. However, hot masses may occasionally be malignant and therefore radiosialography is unreliable and is not recommended.