Computed Tomography (CT) Scan: About This Test

What is it?

A computed tomography (CT) scan uses X-rays to make detailed pictures of parts of your body and the structures inside your body. During the test, you will lie on a table that is attached to the CT scanner. The CT scanner is a large doughnut-shaped machine.

Why is this test done?

Doctors use CT scans to study areas of the body, such as the brain, chest, belly, spine, bones, or joints. CT scans are also used to assist with or check on the success of a procedure or surgery.

How do you prepare for the test?

In general, there's nothing you have to do before this test, unless your doctor tells you to.

Tell your doctor if you get nervous in tight spaces. You may get a medicine to help you relax. If you think you'll get this medicine, be sure you have someone to take you home.

How is the test done?

Before the test

• You may have to take off jewelry.
• You will take off all or most of your clothes and change into a gown. If you do leave some clothes on, make sure you take everything out of your pockets.
• You may have contrast material (dye) put into your arm through a tube called an I.V.

During the test

• You will lie on a table that is attached to the CT scanner.
• The table slides into the round opening of the scanner. The table will move during the scan. The scanner moves within the doughnut-shaped casing around your body.
• You will be asked to hold still during the scan. You may be asked to hold your breath for short periods.
• You may be alone in the scanning room. But a technologist will watch you through a window and talk with you during the test.

How does the test feel?

The test will not cause pain, but some people feel nervous inside the CT scanner.

If a medicine to help you relax (sedative) or dye is used, you may feel a quick sting or pinch when the I.V. is started. The dye may make you feel warm and flushed and give you a metallic taste in your mouth. Some people feel sick to their stomach or get a headache. Tell the technologist or your doctor how you are feeling.

How long does the test take?

The test will take about 30 to 60 minutes. Most of this time is spent getting ready for the scan. The actual test takes a few minutes.

What happens after the test?

• You will probably be able to go home right away.
• You can go back to your usual activities right away.
• If dye was used, drink plenty of fluids for 24 hours after the test, unless your doctor tells you not to.