Fat People Get More Radiation From X-Rays, Study Shows

By: Rachael Rettner, MyHealthNewsDaily Staff Writer
Published: 04/06/2012 11:04 AM EDT on MyHealthNewsDaily

Obese people may be exposed to more radiation when they undergo a CT scans or X-rays, compared with normal-weight people, a new study says.

The study, conducted using computer models,suggests the organs of obese individuals receive up to 62 percent more radiation energy during a CT scan, compared with those of normal weight individuals.

The increase in radiation exposure occurs because radiologists often increase the power settings when doing scans on obese people, said study researcher Aiping Ding, of the Rensselaer Polytechnic Institute in Troy, N.Y. When scanners are used on their normal settings, the image is blurry because the extra fat tissue shields the organs from the X-rays.

As a result, the machines generate higher-energy X-rays that expose people to more radiation, Ding said.

Very high doses of radiation are known to increase cancer risk, but the risk from doses used in medical imaging tests, are less clear, according to the American Cancer Society.

The increased risk from a single CT scan is small compared to the medical benefit, but it is prudent to avoid unnecessary scans, for any patient, regardless of weight, Ding said.

As long as CT scans are used only when necessary, the benefits of the scan will still outweigh the risks, said Dr. Nagy Elsayyad, an assistant professor in the department of radiation oncology at the University of Miami Sylvester Cancer Center, who was not involved in the study.

The extra risk posed to an obese individual from any one scan is so slight that it will not change the way doctors use the scans, Elsayyad said.

Ding and colleagues generated 10 three-dimensional computer models of normal weight, overweight and obese individuals known as "phantoms." The researchers then simulated a CT scan on the phantoms using different settings, and calculated the radiation exposure for each body type.

On the normal setting, excess fat in the obese phantoms protected organs from radiation, resulting in a 59 percent decrease in radiation exposure to organs deep in the abdomen, such as the colon.

But when the scanner settings were adjusted to obtain a clear image, there was a 59 percent increase in radiation exposure for obese women, and a 62 percent increase in radiation exposure for obese men, compared with normal weight people, the researchers said.

Currently, adjustment of the CT scanner for a better image is done by trial and error. The researchers are developing a software program to cut down on this guess work, which could reduce the amount of radiation people are exposed to. The program allows researchers to test scanner settings and chose one that will minimize the radiation dose while still providing a clear image, Ding said.

The study will be published April 6 in the journal Physics in Medicine & Biology.

Follow MyHealthNewsDaily staff writer Rachael Rettner on Twitter @RachaelRettner. Find us on Facebook.

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Comments

[EntanglementTrick]

06:15 PM on 04/09/2012

smaller people have more heart problems, bigger people get more cancer... So when they crank up the 'thodes and things start getting juicy, the obese get an extra dose of cookin': not only do they get more cancer for having more cells, they get more radiation from scanners who need to increase their phasers to stun plus one...

[Chris Eakin]

05:26 PM on 04/09/2012

Clearly this is left wing conspiracy initiated by Michelle Obama (sarcasm). How dare she try to help the health of the American youth !!

[onionboy]

12:52 PM on 04/09/2012

They neglected to compare it to the risk of not getting a good image from a scan if typical setting are used. That's what would be needed to determine whether the increased setting were detrimental or not.

[Ben Wilson]

12:25 PM on 04/09/2012

Being fat makes you radioactive now! I know I'm blowing it out of proportion but seriously, jog on.

[Johnangry]

12:33 PM on 04/08/2012

Obesity is an economic generator.

An easy solution would be to include liposuction in all health plan. (before some paid PR person with a million graphs and charts comes out about, don't bother)

But what would happen if fat were sucked out?

Your doctor would loose gouge power.
You would walk more, your oil company would lose gouge power.
You wouldn't pay high prices for diet food, your grocer would lose gouge power.
Illness and disease would strike less, your pharmacy would lose the gouge.

Fat makes a lot of money. This info will only send people to the gym via gas guzzling car. They'll go to the market afterward to buy high priced diet food. And when it doesn't work, they'll give the doctor a $50.00 co-pay and the insurance will pay $250 more. He'll tell them something a magazine could have for $3.95 or google for free. Or he'll give them a prescription and they can pay the pharmaceutical industry.

Your doctor wants you fat
Your pharmaceutical company wants you fat
the oil industry wants you fat
the food industry makes you fat and keeps you that way

[llyd wlsh]

10:36 AM on 04/08/2012

"Obesity Raises Risk From Common Medical Test, Study Suggests"

this picture caption you have posted suggests that having a common medical test if you are obese puts you at greater risk.......the simplest solution would be to NOT take the common medical test, thereby reducing your risk....

you have some writers who are pretty sharp and provide considerable information in their postings

some of your other peeps don't seem to understand english very well....i know that i am perfectly capable of butchering my native tongue but i don't get paid to write so less is expected of me

[eric14]

07:03 PM on 04/08/2012

Test are carried out to establish if person has an illness. Not having the test stops that investigation.

[jonny dipstick]

08:57 AM on 04/08/2012

Crud, I need to go for a jog.

[rg9rts]

07:01 AM on 04/08/2012

NOW this is rocket science!!!! They increased the power settings, and you are surprised that they get more radiation. Not junk science but junk article. At least you didn't say that they provided a bigger target. NLOL

[ActaNonVerbaNow]

04:33 AM on 04/08/2012

Obesity is a son of a gun.

[NunyaBus99]

11:29 AM on 04/07/2012

If one is obese, the extra radiation is the least of their problems. Now when they do it, there should be a disclaimer read and if the patient still wants the scan, then so be it.

[SeptimusDSX]

09:11 AM on 04/07/2012

Really now? Is this what science has become, a contest on how many ways you can state the obvious?

[KrautMan]

04:26 AM on 04/08/2012

It is surely not obvious that 'the organs of obese individuals receive up to 62 percent more radiation energy during a CT scan'.