What It Is
An abdominal CAT scan is a painless test that uses a specialized X-ray machine to take pictures of a patient's organs, blood vessels, and lymph nodes.
The doughnut-shaped machine circles the body, taking pictures to provide cross-sections of internal organs from various angles. These pictures are sent to a computer that records the images. It can also put them together to form a three-dimensional (3-D) image. A technician does the CAT scan (also called a CT scan or a computed axial tomography scan).
Why It's Done
An abdominal CAT scan can detect signs of inflammation, infection, injury or disease of the liver, spleen, kidneys, bladder, stomach, bowels, pancreas, and adrenal glands. It is also used to look at blood vessels and lymph nodes in the abdomen. A doctor may order a CAT scan to find the cause of abdominal pain, diagnose an illness, or evaluate the effects of an injury.
Your child may be asked to remove all clothing and accessories and change into a hospital gown because buttons, zippers, clasps, or jewelry might interfere with the image.
Your child may have to avoid eating and drinking anything for a few hours before the scan to make sure that the stomach is empty. Fasting is required if your child will be sedated or needs to receive a contrast solution, which highlights certain parts of the body so doctors can see more detail in specific areas of the CAT scan.
If you suspect that your daughter is pregnant, it's important to tell the technician or doctor because there's a small chance that the radiation from the CAT scan may harm the developing baby. But if the CAT scan is necessary, precautions can be taken to protect the baby.
Procedure times vary, from several minutes to 45 minutes. The time depends on the age of the child, whether contrast solution is given, and whether sedation is needed. The actual exposure time to radiation is much less.
Your child will enter a special room and lie down on a narrow table. An abdominal CAT scan is performed with your child lying on his or her back, side, or stomach.
If contrast solution is required, it may be given through an IV that will be placed in your child's hand or arm in the radiology area. Placing the IV will feel like a quick pinprick, but the solution is painless as it goes into the vein. Otherwise, your child may be given a special fluid to drink before the procedure. Some kids don't like the taste, but it can be flavored to make it more appealing.
The technician will position your child, then step behind a wall or into an adjoining room to operate the machine, viewing your child through a window. The technician will speak to your child through an intercom. You'll be able to stay in the CAT scan room until the test begins, then you'll join the technician in the outer room or you might be asked to sit in a waiting room. If you stay with the technician, you'll be asked to wear a lead apron to protect certain parts of your body.
Sedation may be required if your child can't lie still for the scan, which is common among infants and young kids. Sedation medicines are given through an IV line and help to keep a child comfortable during the CAT scan.
When the procedure begins, the table moves through the hole in the center of the CAT machine. Older kids will be asked to hold their breath and stay still for a few seconds at a time to prevent the images from being blurred.
What to Expect
Your child won't feel anything as the CAT scan is taken, but may hear whirring and buzzing sounds as the machine works. The room may feel cool due to air conditioning used to maintain the equipment. Some kids may feel uncomfortable lying still for extended periods.
After the scan is complete, your child will be asked to wait a few minutes so the technician can review the quality of the images. If they're blurred, parts of the CAT scan may need to be redone. If your child required sedation, it will take a little while for the medicine to wear off.
Getting the Results
The CAT scan images will be looked at by a radiologist (a doctor who is specially trained in reading and interpreting X-ray images). The radiologist will send a report to your child's doctor, who will discuss the results with you and explain what they mean.
Results are usually ready in 1-2 days. If the CAT scan was done on an emergency basis, the results can be made available quickly. In most cases, results can't be given directly to the patient or family at the time of the test.
In general, CAT scans are very safe although more radiation is required than in a regular X-ray. Any exposure to radiation poses some risk to the body, but the amount used in an individual CAT scan procedure isn't considered dangerous. It's important to know that radiologists use the minimum amount of radiation required to get the best results.
If your daughter is pregnant, there's a risk of harm to the developing baby, so precautions must be taken.
Contrast solutions are generally safe, with a very low incidence of allergic reactions. They may contain iodine, which might cause problems for kids with an iodine or shellfish allergy, and some other illnesses. Talk with the doctor if you have any concerns about a possible allergy.
Helping Your Child
You can help your child prepare for a CAT scan by explaining the test in simple terms before the procedure. You can describe the room and the equipment that will be used, and reassure your child that you'll be close by. For older kids, be sure to explain the importance of keeping still so the scan can be completed quickly and parts of it don't have to be repeated.
If You Have Questions
If you have questions about why the abdominal CAT scan is needed, speak with the doctor. You can also talk to the CAT scan technician before the procedure.
Reviewed by: Kate M. Cronan, MD
Date reviewed: September 2008