Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . Lung volumes are low limiting assessment . There is retrocardiac streaky opacity which could represent atelectasis versus pneumonia . Otherwise the lungs are clear . No pleural effusion or pneumothorax . No signs of congestion or edema . Cardiomediastinal silhouette is stable . Bony structures are intact . No free air below the right hemidiaphragm .
    OUTPUT:
    
Retrocardiac opacity , question atelectasis versus pneumonia .