Are CT Scans Safe?

This article explains CT scan safety, including radiation, contrast dye, and how we minimise risk.

CT safety at a glance

• CT uses X-rays, so it involves ionising radiation.
• Scans are performed only when medically justified.
• Dose is carefully controlled and kept as low as reasonably achievable.
• Most patients can resume normal activity immediately after the scan.

Radiation and risk

CT radiation can slightly increase lifetime cancer risk, but for an appropriate clinical question the diagnostic benefit outweighs this small risk. Your referrer and radiologist consider your symptoms, alternatives, and prior imaging before recommending CT.

When CT is recommended

• Urgent conditions where speed matters, such as trauma or suspected stroke.
• Problems best seen with CT, such as lungs, bowel, bones, and internal bleeding.
• Treatment planning and follow up when precise anatomical detail is needed.

Children and pregnancy

• Children: We adjust techniques for size and age and use CT only when it changes care. Ultrasound or MRI may be considered first.
• Pregnancy: Tell staff if you are or might be pregnant. We will discuss urgency, alternatives, and shielding or deferment where appropriate.

Contrast dye safety

Some CT scans use iodine-based contrast to highlight organs and vessels. Most people tolerate it well. A brief warm sensation or metallic taste can occur and passes quickly.

• Mild reactions can include nausea, itch, or hives.
• More significant reactions are uncommon. We are equipped to manage them.

Please tell us before your scan if you have

• Previous reaction to iodine contrast.
• Kidney disease or are on dialysis.
• Diabetes medicines containing metformin.
• Thyroid disease.
• Asthma or multiple severe allergies.
• Pregnancy or possible pregnancy.

How we minimise radiation

• We scan only the body area needed and avoid repeat phases unless essential.
• Automated exposure control tailors dose to your size.
• Low dose protocols and iterative reconstruction maintain image quality at lower dose.
• We check your prior imaging to avoid unnecessary duplication.

After your scan

• If you had contrast, drink water across the day.
• Minor bruising at the IV site can occur.
• Seek help if you develop worsening pain or swelling at the cannula site, hives, wheeze, or breathing difficulty.

FAQs

Is CT safe? CT is considered safe when medically justified and performed with dose optimisation.

Can I have CT while breastfeeding? Yes. If contrast is used, you can continue breastfeeding.

Will I feel anything? The scan is painless. Contrast may cause brief warmth or a metallic taste.

Are there alternatives? Depending on the question, ultrasound or MRI may be suitable. Your doctor and radiologist will advise.

Key point

For the right clinical question, CT provides fast, accurate answers with low, controlled risk. Talk to your doctor or our team if you have questions about safety in your situation.