Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes remain low . Retrocardiac opacities and indistinctness of the left hemidiaphragm have increased . No pleural effusion or pneumothorax . Heart size is normal . Cardiomediastinal and hilar silhouettes are unremarkable .
    OUTPUT:
    
1 . No pneumothorax . 2 . Increased retrocardiac opacity and indistinctness of the left hemidiaphragm may again reflect increasing left basilar atelectasis or developing pneumonia .