If you select a chest CT on the website, the risk is still very small, but by using the calculator at least we can open up a conversation and have real numbers when people talk about this.

DM: Isn't the real issue here about children?


MH: Yes. In the "About" section of the (www.xrayrisk.com) website, (the middle graph), the risk for children is shown on the left and adult on the right from the same radiation dose. This demonstrates increased risk for the young partly because the cancers that are induced by radiation take 5-10 years to develop. So if you are 80 years old, get all the CT scans you want.

Most physicians are very cautious with children and the doses on the site are adult doses. There has been a strong campaign by the ACR to make sure people aren't using adult doses for kids (Image Gently). They have done a great job of bringing down the dose.

DM: What about radiation risk for the health care professionals such as the technologist? Are they under any increased risk?

MH: Yes, and the National Committee on Radiological Protection and Measurements (NRCP) monitors their risk. Hospitals have physicists whose job is to ensure their safety. I wear a badge that I replace very month. I send it in to a company and they tell me what my radiation dose was for the month. The government sets yearly limits, so if I were to go above the safe limit, then I would not be able to do some procedures.

DM: So interventional radiologists are at greater risk.

MH: Yes, those physicians get some of the highest radiation doses from working. Most of my days are spent behind a computer reading X-rays or CT scans
and I get no radiation exposure.

For an interventional radiologist who reads X-rays live to do procedures, they do get larger doses and are monitored very closely by the government and the hospital administration to make sure that this is done safely. The exposure limit for workers is 50 mSv per year, which is equal to about 7 chest CTs. The technicians who take the X-rays have equipment that lets them stand far away or behind a wall. But they are also monitored and protected. Exposure falls off every quickly just a few feet away from the equipment.

DM: How much radiation exposure do health care professionals receive?

MH: Other than interventional radiologists, the people who get the most are the technicians. They get about 2 mSv per year, in general that is about the same as getting a head CT.

It is important to point out that there has never been a reported case of cancer as the result of medical imaging. Most of the data is from the survivors of Hiroshima and Nagasaki. We are just trying to be as careful as we can.

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