Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A single portable chest radiograph excludes the left costophrenic angle and is slightly rotated . Within this limitation , cardiomediastinal and hilar contours are unchanged . Bibasilar streaky opacifications , left greater than right , likely represent atelectasis , though can not exclude an infectious process in the appropriate clinical setting . Degenerative changes are noted at the bilateral humeral heads and acromioclavicular joints .
    OUTPUT:
    
Bibasilar streaky opacifications , left greater than right , likely represent atelectasis , though infection not excluded .