Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . Lung volumes are low . There is a retrocardiac opacity containing air - fluid level consistent with a large hiatal hernia as seen on prior . There is mild streaky left basal opacity abutting the hiatal hernia , which could represent atelectasis versus an early pneumonia / aspiration . Right lung is clear . No large effusion or pneumothorax . Scoliotic deformity of the lumbar spine is partially visualized .
    OUTPUT:
    
Left lower lobe opacity abutting the hiatal hernia , question atelectasis versus early pneumonia / aspiration .