Thanks for the query to H.C.M. Forum.
Infiltration means due to some disease this part got damage. Atelectasis
means part collapsed due to some pathogens or disease ( bacteria).
You should concern about these infiltration and atelectasis.
Physical examination as well complete clinical examination will find out the cause and nature of disease.
Consult a physician and get his opinion.
Still you have some doubt ,than upload the X ray
( old one ) and recent and we explain whole situation.
Good luck .