What is a CT scan?
In conventional X-rays, a beam of energy is aimed at the body part being studied. A plate behind the body part captures the variations of the energy beam after it passes through skin, bone, muscle and other tissue. While much information can be obtained from a regular X-ray, specific detail about internal organs and other structures is not available.
What is an ultrafast/electron beam CT scan?
With CT scans, the X-ray beam moves in a circle around the body. This allows for many different views of the same organ or structure, and provides much greater detail. The X-ray information is sent to a computer which interprets the X-ray data and displays it in two-dimensional (2-D) form on a monitor.
CT scans may be done with or without contrast. Contrast is a substance taken by mouth or injected into an intravenous (I.V.) line that causes the particular organ or tissue being studied to be seen more clearly.
What is the preparation for a CT scan?
If the child’ s doctor schedules a CT scan of the heart or chest and decides to use contrast dye, the child may need to be NPO (fasting, nothing by mouth) for four hours prior to the procedure. Parents will receive instructions about this from the child’ ‘ s doctor or another healthcare professional.
Parents will need to let the child’ ‘ s doctor know if their child has ever had a reaction to any contrast dye, or if he is allergic to iodine or seafood. If a teenage daughter is pregnant or could be pregnant, parents should notify the doctor prior to the procedure.
Children may receive a mild sedative before the procedure to make them feel more comfortable, and to help them to remain still and quiet during the procedure, which may last 30 to 60 minutes.
Parents may be able to stay with their child in the CT scan room until he becomes sleepy, but are usually asked to wait in another area during the procedure to avoid exposure to unnecessary radiation.
How is the CT scan performed?
The CT scanner is located in a large room. The child will lie on a narrow table that slides into the hollow tube-shaped scanner.
The child may have an intravenous (I.V.) line for contrast medication. The contrast medication may be injected prior to or during the procedure.
The CT doctor and staff will be in an adjacent room where the equipment controls are located. However, they will be able to see the child through a large window and will be monitoring him constantly during the procedure. If the child is not sedated, he will be given a call bell device to let the staff know if he needs anything during the procedure. Speakers are located inside the scanner so that the child can hear instructions from the CT staff and they can hear the child respond.
Once the procedure begins, the child will need to remain very still at all times so movement will not adversely affect the quality of the images. At intervals, he will be instructed to hold his breath, if possible, for a few seconds. He will then be told when to breathe. The child should not have to hold his breath for longer than a few seconds, so this should not be uncomfortable. Young children who cannot hold still for the procedure will be given medication to help them relax or sleep during the CT scan.
If the CT scan is being done with and without contrast, the child will receive contrast medication through an I.V. about halfway through the procedure. He may feel warm or flushed just after the dye goes into the vein—this is a normal feeling and it will go away shortly.
Once the procedure is finished, the table will slide out of the scanner. If your child received medication for relaxation or sleep, he will be monitored until the medicinewears off and he is awake again. If an I.V. was inserted, it will be taken out after the procedure is done and the child is awake.
Parents may be asked to wait for a short time while the radiologist reviews the scans to make sure they are clear and complete. If the scans are not sufficient to obtain adequate information, additional scanning may be done.
The test normally takes approximately 30 to 60 minutes.
What happens after the procedure?
Without sedation, the child should be able to resume normal activities immediately, unless the child’ ‘ s doctor instructs you otherwise.
With sedation, the child may feel groggy, tired or sleepy for a period of several hours after the procedure. However, the sedation effects should disappear within a day or so.
Depending on the results of the CT scan, additional tests or procedures may be scheduled, to gather further diagnostic information.