Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lung volumes are slightly low . Increased retrocardiac density likely represents atelectasis . The heart is mildly enlarged . There is no pleural effusion or pneumothorax . No focal consolidation or overt pulmonary edema is present . Median sternotomy wires , mitral valve replacement , and pacemaker device are unchanged in position . There has been interval progression of a mid thoracic vertebral body compression fracture since the prior study .
    OUTPUT:
    
1 . Low lung volumes with increased retrocardiac density , likely atelectasis . 2 . Interval progression of anterior wedge compression deformity of a mid thoracic vertebral body .