Definition of Sinus CT scan:

A computed tomography (CT) scan of the sinus is an imaging test that uses x-rays to create detailed pictures of the air-filled spaces inside the face (sinuses).

How the test is performed:

You will be asked to lie on a narrow table that slides into the center of the CT scanner. You may lie on your back, or you may lie face-down with your chin raised.

Once you are inside the scanner, the machine's x-ray beam rotates around you. (Modern "spiral" scanners can perform the exam without stopping.)

A computer creates separate images of the body area, called slices. These images can be stored, viewed on a monitor, or printed on film. Three-dimensional models of the body area can be created by stacking the slices together.

You must be still during the exam, because movement causes blurred images. You may be told to hold your breath for short periods of time. Straps and pillows may be used to keep you still during the procedure.

The actual scan should take about 5 minutes. The entire process should take 15 minutes.

How to prepare for the test:

Certain exams require a special dye, called contrast, to be delivered into the body before the test starts. Contrast helps certain areas show up better on the x-rays.

• Contrast can be given through a vein (IV) in your hand or forearm. If contrast is used, you may also be asked not to eat or drink anything for 4-6 hours before the test.
• Let your doctor know if you have ever had a reaction to contrast. You may need to take medications before the test in order to safely receive this substance.
• Before receiving the contrast, tell your health care provider if you take the diabetes medication metformin (Glucophage) because you may need to take extra precautions.

If you weigh more than 300 pounds, find out if the CT machine has a weight limit. Too much weight can cause damage to the scanner's working parts.

You will be asked to remove jewelry and wear a hospital gown during the study.

How the test will feel:

Some people may have discomfort from lying on the hard table.

Contrast given through an IV may cause a slight burning sensation, a metallic taste in the mouth, and a warm flushing of the body. These sensations are normal and usually go away within a few seconds.

Why the test is performed:

CT rapidly creates detailed pictures of the sinuses. The test may diagnose or detect:

• Birth defects in the sinuses
• Infection in the bones of the sinuses (osteomyelitis)
• Injury to the face over the sinuses
• Masses and tumors, including cancer
• Nasal polyps
• The cause of repeated bloody noses (epistaxis)
• Sinus infection or sinusitis or a sinus infection

This results from this test may also help your health care provider plan for sinus surgery.