Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral views of the chest provided . Midline sternotomy wires again noted with a prosthetic cardiac valve . Patient is slightly rotated to his right . There is no convincing evidence for pneumonia or edema . No large effusion or pneumothorax . Patient 's chin partially obscures the superior mediastinum . Overall heart and mediastinal contours appear unchanged . Bony structures are intact . Degenerative changes are again seen at the right shoulder .
    OUTPUT:
    
As above . No pneumothorax .