Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes remain low with persistent linear left basilar atelectasis . There is new airspace opacity in the left mid and lower lung . There are background changes of mild congestive heart failure however the appearances are suspicious for infection given the asymmetry . Alternatively , this could represent asymmetric pulmonary edema . No pleural effusion seen . No pneumothorax .
    OUTPUT:
    
Airspace opacity in the left mid and lower lung likely represents infection however this could asymmetric pulmonary edema could have an identical appearance .