Radiation is everywhere: Why PET/CT examination is safer than you think
When people hear that they will be given radioactive drug before a PET/CT imaging, it is perfectly normal for them to feel nervous. Radiation has an alarming reputation and for understandable historical reasons. But the reality of radiation involved in a PET/CT imaging test is very different from what most people imagine. In fact, you're probably exposed to more radiation on a long-haul flight than you realize.
Radiation is a natural part of life
Radiation is not something that only exists in laboratories or medical facilities. They are everywhere and constantly around us. This is called background radiation and comes from:
•Soil and buildings: Naturally occurring radioactive elements such as radon gas, uranium, and thorium are present in the soil, rocks, and materials used to build our homes.
•Food and water: Small amounts of natural radioactive elements are present in many foods, including bananas, Brazil nuts, and some mineral waters.
•The sun and space: Cosmic radiation is constantly reaching us from space. The Earth's atmosphere provides some protection, but the higher you climb, the more you are exposed.
•Our bodies: We all contain naturally occurring radioactive elements, including carbon-14 and potassium-40 that emit tiny amounts of radiation from our own bodies.
The average person in Europe receives about 2-3 millisieverts (mSv) of radiation per year from natural background sources alone. Cyprus, located at a Mediterranean elevation and built on granite-containing geology, has its own natural background level in this range.
What about flights?
At a cruising altitude of about 35,000 feet, the atmosphere is thinner, which means less protection from cosmic radiation. A transatlantic flight from Larnaca to New York exposes a passenger to radiation of approximately 0.05–0.1 mSv. A frequent passenger or pilot accumulates much more radiation over the course of their career. This is not considered dangerous, it is just a fact of modern travel, accepted and regulated by aviation authorities.
How does a PET/CT imaging test compare?
A typical PET/CT imaging of the whole body at Positron Diagnostics includes two radiation components:
•The 18F-FDG radiotracer injection: The radioactive ingredient has a half-life of just 110 minutes which means it loses half of its radioactivity every 110 minutes and is essentially removed from the body within a few hours.
•The CT: A low-dose CT scan is performed alongside the PET to provide an anatomical reference.
The combined effective radiation dose from a standard PET/CT examination is about 7-10 mSv, equivalent to about 2-3 years of physical background radiation, or about the same as living in a higher altitude city for a few years.
To put it simply: the radiation dose from a PET/CT exam is the same order of magnitude as what you would naturally accumulate in two to three years just living on Earth.
How Positron Diagnostics keeps your dose as low as possible
At Positron Diagnostics, we follow the principle of ALARA (As Low As Reasonably Achievable). This means:
•Each imaging test is tailored to the patient's weight and clinical query, which means we never use a one-size-fits-all dose.
•The Discovery IQ Gen 2 PET/CT scanner uses advanced detector technology that produces excellent image quality at lower radiation doses than older systems.
•Our forensic physicists regularly review dosage protocols to ensure they meet the latest international guidelines.
•We recommend PET/CT examination only when the clinical benefit clearly outweighs any risk.
Radiation is not something to be feared, but it is something to understand. Medical imaging using radiation has saved millions of lives by enabling the accurate diagnosis of cancer, heart disease, brain disease, and infections. The doses involved are small, carefully controlled and overshadowed by the benefit of the information they provide.
If you have any questions or concerns about radiation before your PET/CT examination, our team is always happy to talk to you.
Contact Phone: +357 22 053 555
Address: 215 Spyrou Kyprianou Avenue, 2047 Strovolos, Nicosia