How should I prepare?
You'll meet with your doctor to learn about the test and how to prepare. Here are some tips:
Tell your doctor about your allergies. Your doctor especially needs to know if you have asthma or are allergic to any foods or medications. If you've had a bad reaction to contrast in the past, you may need to take medication the day before the scan.
Tell your doctor all the medications you take, including herbs and over-the-counter drugs.
You may be prescribed medication to take a few days before your procedure.
If your CT scan will use contrast and you take metformin (Glucophage), you'll need to stop taking it the day of the procedure and wait to restart it until at least 2 days after. (You'll need blood tests before starting it again.) Monitor your blood glucose during this time, and call your doctor if it's higher than 300 mg/dL.
If directed, avoid food and drink before the test. If contrast will be used in your CT scan, do not eat or drink anything for 2 hours before the scan.
Wear comfortable clothes. If your clothes have metal in them, you'll need to put on a gown.
Tell your doctor and the CT technician if you are pregnant or you may be pregnant.