CT (Computed Tomography)

What is a CT scan?

A CT scan (sometimes called a "CAT scan") combines X-rays and a powerful computer to create detailed cross-sectional pictures of the inside of your body. Modern scanners are open and quick — capturing dozens of images in just a few seconds — and produce clear views of bones, organs, blood vessels, and soft tissue.

What it's used for

• Trauma and emergency evaluation
• Chest, abdominal, or pelvic pain
• Cancer detection, staging, and follow-up
• Surgical planning
• Heart and blood vessel imaging (CT angiography)
• Kidney stones, gallstones, and infections
• Lung nodule screening and follow-up

How to prepare

For most CT scans, no special preparation is needed. If your exam uses IV contrast (a special dye that highlights blood vessels and organs), you may be asked not to eat for 4 hours beforehand.

• Wear loose, comfortable clothing without metal (zippers, snaps, underwire)
• Tell us if you have kidney problems, allergies, or might be pregnant
• If you take metformin for diabetes, ask whether to pause it before contrast
• Bring a list of your current medications

What to expect during your exam

You'll lie on a padded table that slides through a large ring-shaped scanner. The scanner is open at both ends — not a tunnel — and most patients find it comfortable. You'll need to hold still for a few seconds at a time, and sometimes hold your breath briefly.

Most scans take 5 to 20 minutes. The exam itself is painless. If contrast is given through an IV, you may feel a brief warm or flushed sensation throughout your body — this is normal and goes away in a minute or two. The technologist watches and talks with you the whole time.

Is it safe?

CT uses ionizing radiation, but doses are kept as low as possible while still giving your doctor the information needed to care for you. We tailor each scan to your size and the medical question being asked.

If you're pregnant or might be, please tell us — we'll discuss alternatives or use protocols that minimize exposure to your baby. Reactions to IV contrast are uncommon, and we screen carefully for risks beforehand.

After your exam

You can return to your normal day right away. If you received contrast, drink extra water to help your body clear it. Your radiologist will interpret the images and send a report to your ordering physician — usually the same day.