Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest are provided . Lung volumes are low . The heart is mildly enlarged , though this is stable . Midline sternotomy wires and mediastinal clips are again noted . There is no definitive sign of pneumonia or overt CHF . There is a small left pleural effusion noted . Bony structures are intact . No free air below the right hemidiaphragm .
    OUTPUT:
    
Mild cardiomegaly , small left pleural effusion . Otherwise , unremarkable .