Reza Fazel: If the test is being done for a clear medical reason and the patient can expect any benefit from that based on getting a diagnosis or being treated, then that benefit will easily outweigh the small radiation risk.
Dr. Reza Fazel is a cardiologist at Emory University in Atlanta. He spoke with EarthSky about the millions of people each year who get medical imaging tests, such as CT scans. In a recent study, Fazel used claims data from an insurance company to get an estimate of how much radiation the average patient in the United States is exposed to from medical imaging.
Reza Fazel: The majority of people are getting pretty low doses from medical imaging comparable to what you get from natural background sources. But about 2% of the population got higher doses that were concerning. That may sound like a small proportion, but when it’s translated to the US general population, it’s about 4 million people getting these kinds of doses that are a bit more concerning.
That’s why, Fazel cautioned, imaging tests such as whole body CT scans for screening healthy people may not be worthwhile.
Reza Fazel: There’s absolutely no evidence that that leads to any health benefit and you’re getting significant doses of radiation from that test. So that would be a good example of the types of testing that we should avoid.
One clear medical reason for doing an imaging test, he said, is to diagnose and treat illness.
Reza Fazel: If someone has clear symptoms of chest pain that’s typical for blockage of the blood vessels that feed the heart in coronary heart disease, then doing the test will have a much more significant impact on their health and their quality of life and reducing their risk of death and morbidity as compared to the very small risk of developing cancer from these relatively low doses of radiation.
Fazel found that CT scans – used to do cross-sectional imaging of the body – and nuclear medicine scans – tests that use radioactive tracers inside the body – contribute the most to higher doses of radiation.
Reza Fazel: The key thing is that these two types of studies are associated with higher doses of radiation, but more importantly, the rates of use of these types of studies have been rising pretty dramatically over the past few decades, which is what causes them to contribute the most to radiation exposure.
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