Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post sternotomy and aortic valve replacement , as before . There is a new moderate new left - sided pleural effusion with associated atelectasis in basilar parts of the left lower lobe with lesser opacities also suggesting partial areas of atelectasis in the superior segment and lingula . Opacification of the posterior right lower hemithorax , however , has resolved . Background lung parenchyma appears within normal limits .
    OUTPUT:
    
Substantial new left - sided pleural effusion with areas of opacification and volume loss , probably compatible with atelectasis , although not entirely specific .