Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest are provided . There is residual subcutaneous emphysema along the left lateral chest wall , which is improved from prior exam . There is bibasilar opacity which likely represents a combination of atelectasis and effusion , overall increased from prior exam . The heart remains mildly enlarged . The mediastinal contour is unchanged . There is no pneumothorax . Retrocardiac density could also represent a hiatal hernia . The bony structures are intact .
    OUTPUT:
    
Increased bibasilar opacity likely representing a combination of atelectasis and effusion , though pneumonia not entirely excluded . Improving left chest wall subcutaneous emphysema . Please refer to subsequent CTA chest for further details .