Contrast Material for Computed Tomography Scan

Contrast Material

Contrast material (helps your body part show up better in the pictures)

If you need contrast material for your CT examination, it will be given to you by mouth (oral contrast) or through your vein (intravenously (IV)). You should inform your caregiver of any medications you are taking, and if you have any allergies, especially to contrast materials. If you have a history of contrast reaction, your ordering physician is responsible for prescribing the premedication for you.

The American College of Radiology recommends the following premedication:

• Prednisone 50 mg taken by mouth 13 hours, 7 hours, and 1 hour prior to the examination. 
• Benadryl 50 mg taken by mouth 1 hour prior to the examination.

Oral (drinkable) contrast material or intravenous contrast material

You may need to drink a liquid that may be either water- or barium-based if you are having an abdominal or pelvic CT scan. Depending upon your type of examination, you may have to come early to the Department or imaging center in order for the oral contrast agent to pass from the stomach into the small intestine.

There are two different chemical compositions for oral contrast that we use in the Radiology Department at Stanford. These include thin solutions of barium and water-based contrast agents.

There will be specific instructions related to the ingestion of water-based contrast agents for these three separate examinations, so please read the instructions carefully and be sure to come to the Department with sufficient time to drink the contrast material required.

Intravenous (IV) contrast liquid

You may be given the contrast material in an intravenous (IV) tube that is put into your vein. When the contrast material is put into your vein, you may feel warm or flushed. You may have a metal or salty taste in your mouth or you may feel sick to your stomach. Tell your caregiver if you feel like you are going to vomit (throw up). This only lasts 1 to 2 minutes. People who have had an allergic reaction to contrast material may be allergic to this contrast material. Caregivers will take special precautions for your safety if you have these allergies. Nursing mothers should wait for 24 hours after contrast material injection before resuming breastfeeding.

Diabetic Patients: If you are a diabetic patient taking any medication that contains Metformin (Glucophage, Glucovance, Metglip, Fortamet, Riomet, Avandamet) and are scheduled for an examination that requires IV contrast (CT, IVP, or arthrogram, DO NOT take your medication the day of the examination and for 48 hours after. You MUST follow up with your physician for a blood test and instructions on when to resume this medication.