Overview
A CT scan is a medical imaging test that combines multiple X-ray images with computer processing to create detailed pictures of organs, bones, blood vessels, and soft tissues. It is used in many parts of the body, including the head, chest, abdomen, pelvis, and spine. CT can help healthcare professionals look for the cause of symptoms, guide procedures, or monitor a known condition.
Who Is Affected
People of all ages may need a CT scan, including children and older adults, but the reason for testing varies. It is commonly used after injuries, for sudden severe symptoms, and when other tests do not show enough detail. Children and pregnant people may need extra discussion about benefits and risks because radiation exposure is an important consideration.
Prevention
A CT scan itself is not usually something to prevent, but unnecessary imaging can often be avoided by sharing a full medical history and previous test results with the healthcare team. Let the team know if you are pregnant or may be pregnant, have kidney problems, have had a reaction to contrast dye, or have diabetes or thyroid disease. Bringing earlier scans can sometimes reduce repeat testing.
Diagnosis and Tests
Before the scan, you may be asked not to eat for a few hours if contrast is being used. During the test, you lie on a table that moves through a ring-shaped scanner while images are taken; it is important to stay still. Contrast may be swallowed, injected, or given another way depending on the body part being studied. A radiologist reviews the images and sends a report to the healthcare professional who ordered the test.
Living With It
Most people can return to normal activities soon after a CT scan, especially if no sedation was used. If contrast dye was used, you may be told to drink fluids unless a healthcare professional has given different instructions. Keep a record of major imaging tests, especially if you have long-term health conditions and need repeated scans.
When to Seek Medical Care
Contact a healthcare professional if you have questions about why a CT scan was ordered, how to prepare, or what the results mean. Seek medical advice promptly if you develop a rash, swelling, breathing difficulty, severe vomiting, or feel unwell after receiving contrast dye. Also ask for guidance if you have kidney disease, are on dialysis, or are pregnant and a CT scan has been recommended.
When It May Be an Emergency
A CT scan is often used in emergencies such as major injury, stroke symptoms, severe headache, chest pain, or sudden trouble breathing. In these situations, the urgency of finding the cause may outweigh concerns about radiation. Emergency symptoms should be assessed right away rather than delayed because of fear about the test.
Questions to Ask a Healthcare Professional
You may want to ask: Why do I need this CT scan, and what part of the body is being checked? Will contrast dye be used, and are there risks for me? Are there other imaging options, such as ultrasound or MRI, and when will I get the results?