What are Contrast Agents?
Contrast agents are used to image tissues and structures that are not normally seen, or not seen very well. Intravenous contrast agents are used to enhance organs and visualize blood vessels. Oral contrast agents are used to visualize the digestive tract.
How do CT scans differ from MRI scans?
CT and MRI images sometimes look very similar, but the equipment used to perform the scans is different. CT uses ionizing radiation just as with a routine X-ray, while MRI uses a magnetic field. Depending on the clinical indications, one may be preferred over the other, or both may be desirable. CT scanners are faster and as a result, claustrophobia and movement are not as problematic as with the MRI scanner.
Who performs the CT scan?
Medical radiation technologists specially trained in the operation of CT scanners perform the procedure. The technologist also administers oral and intravenous contrast.
What will I feel during the scan?
CT scanning causes no pain, just as a routine X-ray is painless. If intravenous contrast is used, you may feel warm and flush and get a metallic taste in your mouth. These sensations normally disappear after a few minutes.
How long will the scan take?
The time required will depend upon the type of scan. If oral contrast is required, about 45 to 60 minutes is needed for the contrast to move through your digestive tract. Actual scan times vary from a few seconds to several minutes. If no oral contrast is required, the examination will take about 15 to 30 minutes, including the time for intravenous preparation and interview. In some cases additional scanning is required as scans are tailored to suit individual diagnostic needs.
Will I need to drink anything?
Most abdominal scans require the patient to drink a barium sulfate oral contrast mixture. This mixture is flavored and not at all unpleasant. Oral contrast highlights the stomach and upper intestine providing the radiologist with a detailed image for review. If you are scheduled for a CT scan requiring oral contrast, you will be asked to arrive one hour before the scan time.
Can my spouse/friend stay in the room with me?
No. CT scanners use ionizing radiation and only the patient requiring the scan is permitted in the room.