Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP and lateral upright views of the chest were obtained . Compared to the prior examination , there is improved lung expansion as well as interval decrease in bilateral pulmonary opacities . Retrocardiac opacification remains and could be due to aspiration , pneumonia or atelectasis . Left lower lung linear opacities likely represent atelectasis . The bones and soft tissues are unremarkable .
    OUTPUT:
    
Interval decrease in pulmonary vascular congestion . Residual opacities at the left base are most likely due to atelectasis , however , but there could be superimposed aspiration or pneumonia .