Quick answer: The full-body scanners used at U.S. airport security today are millimeter wave scanners, which use low-energy radio waves, not X-rays, so they give no ionizing radiation. The older X-ray «backscatter» body scanners were removed from U.S. airports in 2013, and even those gave a tiny dose. In fact, the flight itself exposes you to far more radiation than any security check, because of cosmic rays at high altitude. A single chest X-ray is roughly equal to a few coast-to-coast flights.
The machines at airport security
| Machine | What it uses | Ionizing radiation to you? |
|---|---|---|
| Full-body scanner (millimeter wave, «AIT») | Low-energy radio waves | No |
| Walk-through metal detector | Weak magnetic field | No |
| Hand-held metal wand | Weak magnetic field | No |
| Bag X-ray machine | X-rays, inside a shielded cabinet | No, unless you climb inside (don’t) |
| Backscatter X-ray body scanner | Very low-dose X-rays | Removed from U.S. airports in 2013 |
Radiation compared
These are approximate effective doses. A microsievert (µSv) is one-thousandth of a millisievert (mSv).
| Exposure | Approximate dose |
|---|---|
| Millimeter wave airport scanner | 0 (non-ionizing) |
| Old backscatter X-ray scanner (per scan) | About 0.05–0.1 µSv |
| One hour of flying at cruising altitude | About 3–6 µSv |
| Coast-to-coast U.S. flight | About 35 µSv (0.035 mSv) |
| Dental X-ray | About 5 µSv |
| Chest X-ray | About 100 µSv (0.1 mSv) |
| Natural background radiation, one day | About 8 µSv |
| CT chest | About 6,100 µSv (6.1 mSv) |
In other words, even the old backscatter scanners gave roughly the same dose as a minute or two of flying. A chest X-ray is about the same as three coast-to-coast flights, and a chest CT is about the same as 175.
Are airport body scanners safe?
Yes. Millimeter wave scanners use radio waves with far less energy than X-rays, and the power is very low. They don’t damage DNA. Health and radiation safety agencies have concluded they’re safe for everyone, including pregnant women and children.
If you’d rather not go through a body scanner, you can usually ask for a pat-down instead.
Pregnancy
- Body scanners and metal detectors: No ionizing radiation; considered safe at any stage of pregnancy.
- The flight: Cosmic radiation from occasional flights is very small. Frequent flyers and crew who are pregnant may want to talk to their doctor about total flight hours.
- Medical X-rays and CT: Different from airport security; see our guide to CT scans during pregnancy.
Pacemakers, insulin pumps and other devices
- Pacemakers and ICDs: Tell the TSA officer and show your device card. Walking through a metal detector or body scanner is generally considered safe; a hand-held wand shouldn’t be held over the device for long. Follow your device maker’s advice.
- Insulin pumps and glucose sensors: Some manufacturers advise against sending pumps or sensors through body scanners or bag X-ray machines. Check your device’s instructions; you can ask for a pat-down and a hand inspection of the device.
- Joint replacements and metal implants: They may set off metal detectors. Tell the officer; a body scanner or pat-down can resolve it.
Had a nuclear medicine test? You might set off radiation alarms
This is the one situation where radiation really matters at the airport, and it’s about you, not the scanner.
After a nuclear medicine scan, PET scan or radioactive iodine treatment, your body gives off a small amount of radiation for a while. Sensitive radiation detectors used at some airports, border crossings and public venues can pick it up, even when the amount is safe for the people around you.
Typical time you might trigger detectors (varies by dose and detector):
| Procedure | Possible detection |
|---|---|
| PET/CT (F-18 FDG) | About 1 day |
| Bone scan, heart scan and most other Tc-99m scans | About 2–3 days |
| Thallium heart scan | Up to about a month |
| Radioactive iodine (I-131) for thyroid | Up to about 3 months |
| Lutetium-177 treatments | Several weeks or more |
What to do:
- Ask the nuclear medicine department for a letter or wallet card with the test, date, radioactive substance and a contact number.
- Carry it when you travel, especially across borders.
- If an alarm goes off, stay calm, show the letter and follow instructions. Officers deal with this regularly.
From the scanner room
[TU EXPERIENCIA: qué tiempo de precaución de viaje indicas en tu servicio tras Tc-99m, F-18, I-131 o Lu-177; si entregas carta o tarjeta; alguna anécdota (sin datos personales) de un paciente que activó un detector.]
FAQ
Do airport body scanners use X-rays?
Not in the U.S. today. TSA body scanners use millimeter waves, a type of low-energy radio wave. The X-ray backscatter scanners were removed in 2013.
Is an airport scanner more radiation than a medical X-ray?
No. Today’s scanners give no ionizing radiation. A chest X-ray gives about 0.1 mSv, roughly the same as three coast-to-coast flights.
Are airport scanners safe during pregnancy?
Yes. They don’t use ionizing radiation. You can also ask for a pat-down if you prefer.
Does the bag X-ray machine expose me to radiation?
No. The X-rays stay inside a shielded cabinet. Don’t put your hands or body inside.
Can I fly after a PET scan?
Yes. There are no flight restrictions, but you might set off radiation detectors for about a day. Carry the letter or card your imaging center gives you.
This article is for general information only and is not medical advice. Follow your doctor’s and device manufacturer’s instructions, and check TSA guidance before you travel.
Sources
- TSA. Advanced Imaging Technology; Passengers with disabilities and medical conditions.
- FDA. Products for Security Screening of People.
- ARPANSA. Airport body scanner safety (2025).
- RSNA. Statement on TSA scanners.
- Health Physics Society. What radiation doses do people receive from flying commercially?
- RadiologyInfo.org (ACR/RSNA). Radiation Dose in X-Ray and CT Exams.
- SNMMI. Travel tips for nuclear medicine patients.