Hi, Beth - lemme see if I can help -
The atelectasis is like you said, scarring or collapse of some of the alveoli, the little sacs at the ends of the bronchial tubes where the oxygen goes into the blood stream - I have some of that too, it comes from long-term lung disease, asthma, whatever, that traps air down deep in the lungs - the alveoli die off and scar tissue takes their place - can show up as an opacity on x-ray. The lymph nodes if they are reactive could be simply reacting to a virus or bacteria, not necessarily something malignant, especially as there are no lesions or masses anywhere else. Your spleen would be enlarged if you had some sort of massive infection going on because the spleen is the major organ for the lymphatic fluid and lymph system/nodes.
It is also a good sign if the report did not recommend a follow-up CT scan or MRI. When I see the word "nonspecific" I translate it as "incidental" or "not terribly important." But when it's on MY x-ray, I think it's important, especially if it is not really supposed to be hanging around. But the docs'll blow it off a lot of time. When I see the phrase "Follow-up CT/XRay/MRI recommended for further evaluation," then I am concerned.
What I do for a living is medical transcription, radiology reports and operative notes- also was a scrub nurse x 10 years- quit in Sept 03 due to guess what COPD so I am a little familiar with the terms on your report. Not to mention the years I have spent trying to understand my own test results.
Good luck with your doc visit and please don't be afraid to ask questions. Pin him/her down about the mediastinal nodes, ok?
You are in my prayers!
Mary