Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided demonstrate midline sternotomy wires and a prosthetic cardiac valve . The lungs are clear . No signs of pneumonia or CHF . No effusion or pneumothorax . The imaged osseous structures are intact . Retained barium is noted within the left colon in the upper abdomen . There is a dextroscoliosis of the T - spine incidentally noted .
    OUTPUT:
    
No signs of pneumonia .