Too Much Radiation in CT Scans?

Too Much Radiation in CT Scans?

Mackenzie Thompson

by Mackenzie Thompson

Life Saver, AMC

posted on Nov 7, 2013, at 9:51 pm


CT (computed tomography) scans are x-rays that create a 3D visual by rotating around the head, chest or another body part. Although these are much more detailed than a standard x-ray machine, they subject the body to between 150 and 1,100 times the radiation, which is about a year’s worth of radiation exposure from both natural and artificial sources. All these x-ray beams also can damage DNA and cause mutations that make cells malfunction and grow into tumors. Doctors have always assumed that the benefits outweigh the risks, though.

Researches have worried that the CT scans could increase a patient’s risk of getting cancer since about 4 decades ago, when they started issuing them. In the past decade, many studies have reignited concerns. Researchers estimate that 29,000 future cancer cases could be attributed to the 72 million CT scans performed in the year 2007 in the US. That is about a 2% increase of the 1.7 million diagnoses of cancers every year.

The accuracy of these estimates depends on how scientists measure the underlying link between radiation and cancer originally. Most estimates of the excess cancer risk from CT scans over the past several decades rely largely on a potentially misleading data set: cancer rates among the long-term survivors of the atomic bomb blasts in World War II.

“There are major concerns with taking the atomic bomb survivor data and trying to understand what the risk might be to people exposed to CT scans,” says David Richardson, an associate professor of epidemiology at the University of North Carolina Gillings School of Global Public Health who has done research on the atomic bomb survivors.

About 25,000 atomic bomb survivors were exposed to what equals about 1-3 CT scans. The number of cancer cases that developed over the rest of their lives is not, however, large enough to provide the ability to reliably predict the cancer risk associated with CT scans in the general population today. Given these complications along with renewed concerns about the radiation levels, a dozen groups of investigators around the world have decided to reassess the risk of CT radiation based on more complete evidence.

Fortunately, clinicians and medical associations have already gotten started on finding the key to reducing radiation levels, not wanting to wait for definite results about the risks. Two radiologists at Massachusetts General Hospital, for example, think that they can decrease the x-ray dosage of at least one common type of CT scan by 75 percent without significantly reducing image quality. This is a step closer to reducing the amount of possible harm due to CT scans.

To read the full article, go to Scientific American

About Mackenzie

Mackenzie is a lover of world travel, photography, design, style and Chinese cooking. She is passionate about working towards a purpose, recently graduated from Indiana University with a degree in Media and Marketing, and is currently residing in Manhattan.

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