Some exams use a special dye, called contrast, that is put into your body before the test starts. Contrast helps certain areas show up better on the x-rays.
Contrast can be given in different ways:
- It may be given through a vein (IV) in your hand or forearm.
- It may be given as an injection into the space around the spinal cord.
If contrast is used, you may also be asked not to eat or drink anything for 4-6 hours before the test.
Let your doctor know if you have ever had a reaction to contrast. You may need to take medicines before the test to avoid this problem.
Before having the contrast, tell your health care provider if you take the diabetes medicine metformin (Glucophage). You may need to take extra steps before the test if you take this drug.
Too much weight can cause damage to the scanner's working parts. Find out if the CT machine has a weight limit if you weight more than 300 pounds.
You will wear a hospital gown during the study. You will need to take off all jewelry.