What is an ultrafast/electron beam CT scan?
A newer technology called ultrafast CT (also known as electron-beam tomography, or EBT) is now used, in some cases, to diagnose heart disease. Ultrafast CT can take multiple images of the heart within the time of a single heart beat thus providing more detail about the heart’s function and structures, and also greatly decreasing the amount of time required for a study.
- A three-dimensional (3-D) version of ultrafast CT may be used to assess the pulmonary arteries and veins in the lungs.
- Ultrafast CT scan may also be used to evaluate selected heart defects after birth.
What is the preparation for an ultrafast CT scan?
An ultrafast CT scan can be performed with or without contrast dye. If the child’s doctor schedules an ultrafast 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 several 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 the 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.
How is the ultrafast CT scan performed?
The ultrafast 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 will have an intravenous (I.V.) line if contrast medication is being used. The contrast medication may be injected prior to the procedure 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 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 still at all times so movement will not 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 may be given medicine to help them relax or sleep during the ultrafast CT scan.
If the ultrafast CT scan is being done with and without contrast, the child will receive contrast medicine through an I.V. about halfway through the procedure. He may feel a warm or flushed sensation just after the dye goes into the vein—this is normal and the sensation will go away shortly.
Once the procedure is finished, the table will slide out of the scanner. If the child received medication for relaxation or sleep, he will be monitored until the medication wears 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.
What happens after the procedure?
Without sedation, the child should be able to resume normal activities immediately, unless the ’’doctor instructs 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.
Depending on the results of the ultrafast CT scan, additional tests or procedures may be scheduled to gather further diagnostic information.