My wife gets 30 lbs. I tell her to take Tylenol before she goes.

Little known fact: compression helps with image contrast, making cancer stand out more. From 1990 to 2011, tomosynthesis existed but wasn’t FDA approved because it didn’t work as well as regular mammogram.

But why? Shouldn’t getting slices like a CT through the breast be better than just a plain xray of the breast?

Well, to somewhat over simplify, the first two decades physicians weren’t thinking, they were using tomo to avoid compressing the breast because women complain about compression. A generation of women didn’t get tomo because some idiot physician was trying to be nice instead of rigorous about the physics of cancer and medical imaging.