Headlines from media outlets around the country about radiation exposure can be alarming and confusing. It seems to be dangerous to talk on our cell phones, travel or even undergo medical imaging.
But the truth is, the risk of an average person retaining large amounts of radiation is not likely.
“You might say that the risk of cancer from medical radiation is very small,” said Mark Montgomery, MD, Scott & White radiologist. “According to the New England Journal of Medicine, 1.5 to 2.5 percent of cancers in the U.S. are attributed to medical radiation.”
The largest component of that radiation risk is from CT scanning, cardiac catheterization and PET CTs.
“A routine chest X-ray is very limited exposure,” Dr. Montgomery said. “It’s not much more than a plane flight coast to coast.”
The biological effect that radiation has on human tissue is measured in what’s called a Sievert.
To better understand how this relates to the exposure you’ve encountered, Dr. Montgomery offers a few analogies.
Number of (Mili)Sieverts
|Chest X-ray||0.2mSV||Coast to coast flight|
|Chest CT||8mSV||Slightly more than radiation that comes from nature|
|Body/Head CT||20mSV||Three times dose of a chest CT|
The radiologist said that although some of these medical procedures can expose the patient to a large amount of radiation, the exposure decreases over time.
“It’s not as if you have 100SV acting on you at one time,” he said. “The problem comes if you come back in and get multiple CT scans. Patients that receive repeated scans over a long period of time are at greatest risk for radiation induced problems.”
The more scans you have, the higher your risk of cancer.
Doctors of radiology, including those at Scott & White, are always looking for new ways to limit exposure to their patients.
“There are new things we’re doing to help reduce the doses—using safer scans,” Dr. Montgomery said. “We also educate physicians about the risk of [unhealthy levels] of radiation.”
The radiologist also suggests keeping track of how many scans you’ve had.
“It would be worthwhile for the patient to say to the doctor, I just had a scan about three months ago. Do I really need to have this scan?” he said.
For more information about radiation exposure, the American College of Radiology sponsors a website called www.imagegently.org.