Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest . Left basilar and retrocardiac opacity is seen . Superiorly , the lungs are clear . There is blunting of the left lateral and probably posterior costophrenic angle , potentially due to similar process versus a trace effusion . There is eventration of the right hemidiaphragm . Cardiac silhouette is top normal in size . No acute osseous abnormalities detected .
    OUTPUT:
    
Left basilar opacity potentially due to atelectasis however infection can not be excluded . Possible trace left effusion .