Now do the same for Norris. Move to images 8/9 and 9/9, the upper and lower slices for patient Norris. (Can you do all the steps without looking back at Question #8?)
Does Norris have emphysema?
It's hard to tell because his lungs show 13% dead air. That's so close to the 15% cutoff that he should probably be re-tested.
No, because he can exhale all but 3% of the air in his lungs.
Yes, because his lungs show 21% dead air area.