Because the MRI machine uses a strong magnetic field, which will move objects made with iron or steel, let your doctor know if you have: After the scan, you’ll likely be told to drink lots of fluids to help your kidneys remove the medium from your body. You may be asked to wait for a short time in the radiology department to ensure that you feel well after the exam. If you were given a contrast medium, your doctor, a nurse or the CT technologist performing the scan may give you special instructions. After the exam, you can return to your normal routine. If you receive the contrast medium through an enema - to help highlight your lower gastrointestinal region - you may feel a sense of fullness or cramping. If your exam involves the use of an intravenous contrast medium, you may feel a brief sensation of heat or experience a metallic taste in your mouth. During a CT scan of the head, the table may be fitted with a special cradle that holds your head still. Straps and pillows may help you stay in position. You may lie on your back, side or stomach, depending on the area to be scanned. Diabetes, asthma, heart disease, kidney problems or certain thyroid conditions may increase your risk of a reaction to contrast media.ĭuring the CT scan, you lie on a narrow table that slides through the opening of the gantry. If you have had a prior reaction to contrast media or have asthma or allergies, there’s an increased risk of a reaction to the contrast medium. Be sure to let your doctor know if you have kidney problems since contrast material that’s injected into a vein is removed from your body by your kidneys and could potentially cause further damage to your kidneys. If you’ve had a reaction to a contrast medium in the past, and you need a diagnostic test that may require a contrast medium again, talk to your doctor. If you experience hives, itchiness or swelling in your throat during or after your CT exam, immediately tell your technologist or doctor. In rare instances, an allergic reaction can be serious and potentially life-threatening - including swelling in your throat or other areas of your body.
For people with asthma who become allergic to the contrast medium, the reaction can be an asthma attack.
Most reactions are mild and result in hives or itchiness. Although rare, the contrast medium Involved in a CT scan poses a slight risk of an allergic reaction. It depends on which part of your body is being scanned.