Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The original dictation was lost in therefore the study performed on ___ at 18 : 14 is being dictated on ___ . Low lung volumes . Mild enlargement of the cardiac silhouette . The mediastinal and hilar contours are normal . The pulmonary vasculature is normal . Lungs are clear . No pleural effusion or pneumothorax is seen . The patient is status post thoracotomy with a cortical break in the right fourth posterior rib .
    OUTPUT:
    
No pneumothorax or pericardial effusion .