Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Moderate enlargement of the cardiac silhouette is increased in size compared to the prior study , likely accentuated due to low lung volumes and AP technique . Similarly , the superior mediastinum appears widened and again is likely due to differences in technique and poor inspiratory volumes . Pulmonary vasculature is normal . Lungs are clear . No focal consolidation , pleural effusion or pneumothorax is present . There are no acute osseous abnormalities .
    OUTPUT:
    
Low lung volumes without acute cardiopulmonary abnormality .