Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Relative enlargement of the cardiac silhouette and increased in bronchovascular markings , likely secondary to low lung volumes . The right lung is grossly clear . Left lower lung zone obscured by cardiac silhouette . There is no pneumothorax or pleural effusion . High density structure seen on lateral view adjacent to a lower thoracic vertebral body is likely within bowel .
    OUTPUT:
    
Low lung volumes , but no definite pneumonia .