A computed tomography (CT scan) is a test in which x-rays are taken to study all parts of the body, such as the chest, belly, pelvis or an arm or leg. It can take pictures of body organs, such as the liver, pancreas, intestines, kidney, and heart. It can also study blood vessels, bones, and the spinal cord.
An iodine dye (contrast material) is often used to make it easier to see the CT pictures. The dye can be put in a vein (IV) in the arm, or placed in other areas, such as the rectum or joint. For some CT scans the dye has to be swallowed by mouth.
To get ready for a CT scan you may be asked to:
- Take off clothes and wear a gown.
- Remove any metal objects, such as a belt or jewelry.
- Not eat a few hours before time for the scan.
The contrast material may be used in several ways:
- Oral – swallow a liquid for stomach or esophagus scan.
- Injection – IV in the arm to see gallbladder, urinary tract, liver or blood vessels.
- Rectal – placed thru the rectum to see intestines.
If a child is having a CT scan, the doctor may want to give something to help calm and still them. Too much movement blurs the images and may not show accurate results.
Let your doctor know if you have ever had an allergic reaction to any medication, shellfish, or iodine before you have a CT scan.
A numbing cream (EMLA), before getting an IV, can be applied about one hour before the scan.
Most scans take around 5-20 minutes. CT scans of the brain takes 5-10 minutes. During the test you will lie down on a moving table and placed into the scanner. The scanner will move around you and take x-rays. The person doing the scan (technologist) may ask you to hold your breath at certain points to avoid blurring the images.
After the CT Scan
After the scan you can return home to your normal activities. In some cases, you may be asked to stay for a short time to make sure you are feeling well after the exam. You will be told to drink lots of fluids to help your kidneys remove the contrast material from your body.