What does "emphysematous changes" mean?

It means: lung changes that are consistent with the presence of emphysema. Presumably this was identifies on a chest CT? Your lungs' alveoli are clustered like bunches of grapes. In emphysema, the inner walls of the air sacs weaken and eventually rupture — creating one larger air space instead of many small ones. This reduces the surface area of the lungs and, in turn, the amount of oxygen absorbed.