Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Again seen are multiple median sternotomy wires and mediastinal surgical clips . There are low lung volumes . Allowing for changes due to this , the cardiomediastinal silhouettes are stable and within normal limits . The bilateral hila are unremarkable . The lungs are clear . There is no evidence of pulmonary vascular congestion . There is no evidence of pneumothorax or pleural effusion .
    OUTPUT:
    
No acute cardiopulmonary process .