During a CT scan you will receive an IV, an intravenous line put through a vein in your arm. A technologist will inject a colorless solution called iodinated contrast through the IV that will make your organs easier to see on the scan. (If you have kidney disease or are allergic to iodinated contrast, your doctor can perform the CT without it.) You will lie on a table and move through a donut-shaped machine that takes pictures of your body from different angles.

The test does not hurt, but some people feel uncomfortable lying still on the table. You may feel flushed for a few seconds when you receive the contrast. The length of the exam depends on the parts of your body being scanned, but most exams take less than 10 minutes.