But some doctors say the CT scan exposes patients unnecessarily to harmful radiation, as much radiation as a patient might receive from 400 chest x-rays.

VOA: standard.2010.04.07

Funny story, I met him because at MIT they signed us all up for chest x-rays alphabetically-- that's the way MIT does things, an orderly way.

有趣的是,我在MIT遇到他是因为,我们按姓氏字母顺序,排队去照胸透,MIT做事总是用这种有条理的方式

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