A sinus x-ray is a picture of the air-filled cavities in the front of the skull.

X-rays are a form of electromagnetic radiation -- like light, but of higher energy. They can pass through the body to form an image on film. Structures that are dense (such as bone) look white, air looks black, and other structures are shades of gray.

A sinus x-ray is taken in a hospital radiology department or your health care provider's office. You will be asked to sit in a chair so that any fluids in the sinus may be easily seen on the pictures. The technician may place your head in different positions as the pictures are taken.

Tell your doctor if you are pregnant. Remove all jewelry.

Generally, there is little or no discomfort associated with x-rays.

This test is performed when symptoms of sinusitis or other sinus disorders are present.

The x-ray may detect tumors, obstructions, infections, and bleeding.

Additional conditions under which the test may be performed include:

• Acute sinusitis
• Chronic sinusitis
• Meningitis
• Orbital cellulitis

There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most experts feel that the risk of most x-rays is smaller than other risks we take every day. Pregnant women and children are more sensitive to the risks of x-rays.

A CT scan of the sinuses is often preferred over a sinus x-ray, because it shows more detail.