If intravenous contrast material is to be used in the exam, the CT staff will need to know whether your child has had a reaction to contrast material in the past; is allergic to iodine or seafood; or has kidney disease. The purpose of asking about allergies is to avoid a possibly serious allergic reaction.
Your child may eat and drink as usual and take needed medication as long as no contrast is to be given and no sedative (calming medication) or anesthesia is planned. If either of these situations applies, you may be advised about dietary restrictions or receive other instructions. With sedation or anesthesia your child probably will not be allowed to eat for three to six hours, depending on age, before scanning. In general, sedation is not needed for children while undergoing a CT.
For a head or neck scan you will have to remove your child's glasses, any removable dental braces or dentures, and any jewelry. For a scan of any other part of the body, all metal objects should be removed from the area being examined.
Modern CT imaging avoids the start and stop noises made by the earlier scanners. With modern imaging there are only slight buzzing, clicking or whirring sounds. Your child will need to lie quietly on his or her back. Foam cushions and Velcro straps are placed on the forehead and arms to prevent movement.
A CT scan may take as little as two seconds or as long as several minutes, depending on the information needed. However, preparing for the study will take longer. Some imaging facilities permit parents or other adults to stay in the room when the scan is performed. In this case, you must wear a lead-lined garment to avoid exposure to radiation. St. Mary's uses the lowest possible diagnostic radiation doses possible; however, if you suspect you may be pregnant it would be better for someone else to be with your child. Many children are put off or even frightened by large machines and the general atmosphere of a medical facility; the presence of a parent, close relative, or friend can be very reassuring.
If contrast material is injected into a vein, your child will feel warm all over, but only for a brief time. If your child has to have any contrast administered please ask the technician about LMX cream. The LMX cream is a topical numbing cream that is placed on the skin 20-30 minutes prior to the scan to eliminate any associated pain. When the exam is completed and your child-if sedated-is fully awake, you will be free to return home.