Computed Tomography Health Article

Precautions

CT scans expose the child to radiation, and overuse of CT scanning has received attention from organizations that regulate medical radiation exposure. Although no side effects have been linked to radiation exposure from CT imaging, the Food and Drug Administration has issued guidance to physicians regarding levels of radiation during pediatric CT examinations. New CT scanners have preset imaging features that allow scanning at the lowest radiation dose for the child's weight and age.

Oral contrast may be unpleasant tasting, although chocolate, vanilla, and fruit flavors may be available. Injected contrast can cause sensations of heat or cold through the body. Some children may have allergic reactions to the contrast material, although severe reactions are rare. Parents should inform CT staff if their child has ever had a reaction to any medication, contrast material, or anesthesia. Because contrast material may contain iodine, sensitivity to contrast material may occur if the child has other allergies to iodine or seafood, and CT staff should be informed if the child has such allergies. Also, because CT contrast material can affect kidney function, parents should notify CT staff if their child has kidney disease.

Preparation

Abdominal CT examinations usually require fasting for at least 12 hours before the scan. If the intestines will also be imaged, a laxative before the scan is required. Parents should alert CT staff if children are diabetic and taking insulin, since hypoglycemia can occur with missed meals.

Before the CT scan, the patient has to change into a hospital gown. When oral contrast is necessary, patients need to arrive at least one hour before the scan to drink the contrast solution. During the scan, the child is asked to lie on the CT table. Positioning devices, such as head cradles or knee rests, may be used. For very young or very active children, foam or Velcro restraints may be used to minimize movement during imaging. Or sedation may be used if children cannot remain still. After positioning the child, the technologist inserts an intravenous catheter to inject contrast material.

CT scanners may frighten young children, so prior to the imaging examination, the basic procedure should be explained to help reduce fear. Some radiology departments offer special patient education booklets for children that help explain imaging procedures.

Aftercare

No special aftercare is required following CT scans, unless sedation or general anesthesia was used during the scan. In these cases, children are required to remain in a supervised recovery area for an hour or more following the procedure to be monitored for reactions to anesthesia. If injected contrast material is used, some minor first aid (small bandage, pain relief) for the injection site may be necessary.

Risks

Radiation exposure is a risk during CT examinations. However, the radiation from a CT scan is usually less than that from regular x rays, and the benefits of the examination far outweigh the minor radiation dose received during the scan.

Some children may have reactions to anesthesia or sedation, including headaches, shivering, or vomiting. Rarely, severe anaphylactic reactions can occur that require emergency treatment.

Parental concerns

Younger children may be frightened of the CT scanner, and a parent or other family member may be required to be present in the scanning room. To help alleviate fear, taking the child into the CT room to see the equipment prior to the procedure may be helpful. To reduce risk of radiation exposure, anyone remaining in the scanning room during x-ray delivery will have to wear a lead apron on shield.

BOOKS

Margolis, Simeon, et al. The Johns Hopkins Consumer Guide to Medical Tests: What You Can Expect, How You Should Prepare, What Your Results Mean. New York: Rebus Inc., 2002.

Medical Tests: A Practical Guide to Common Tests. Boston, MA: Harvard Health Publications, 2004.

Segen, J. C., et al. The Patient's Guide to Medical Tests: Everything You Need to Know about the Tests Your Doctor Prescribes. New York: Facts on File, 2002.

Shannon, Joyce Brennfleck. Medical Tests Sourcebook: Basic Consumer Health Information about Medical Tests. Detroit, MI: Omnigraphics, 2004.

PERIODICALS

Harvey, D. "Evaluating Pediatric Trauma: Imaging vs. Lab Tests." Radiology Today 5 (August 2, 2004): 14–16.

ORGANIZATIONS

American College of Emergency Physicians. 2121 K St., NW, Suite 325, Washington, DC 20037. Web site: <www.acep.org>.

American College of Radiology. 1891 Preston White Dr., Reston, VA 20191. Web site: <www.acr.org>.

Radiological Society of North America. 820 Jorie Blvd., Oak Brook, IL 60523–2251. Web site: <www.rsna.org/>.