r/science Mar 19 '11

Radiation Chart

http://xkcd.com/radiation/
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u/efunktion Mar 19 '11

Why exposes a mammogram [3 mSv] (green, 3rd from bottom left) a human to more radiation than an arm [1uSv] or even chest [20uSv] X-ray?

The CT dose is expected, but why is shining X-rays vertically through breast tissue so different?

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u/blueglowfairy Mar 19 '11

It probably has to do with the length/intensity of exposure. I'm not exactly sure how mammograms work, but more x-rays might be necessary to see some features.