Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . Midline sternotomy wires and prosthetic valve again noted . Lungs are clear . No pleural effusion or pneumothorax . Cardiomediastinal silhouette appears normal . Bony structures appear intact .
    OUTPUT:
    
Postoperative changes related to valve replacement , with no acute findings in the chest .