Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient status post aortic valve replacement . Median sternotomy wires are intact and well aligned . Mediastinal clips are again seen . Lung volumes are low . The cardiac size is difficult to assess . Interstitial markings are prominent , similar to the prior examination . Patchy opacities are seen in the bilateral lower lobes , which are not significantly changed since the prior examination . However , consolidation is not definitively excluded . Bandlike retrocardiac opacity is again seen . Again seen is a small left - sided pleural effusion . No pneumothorax is identified .
    OUTPUT:
    
1 . No definite acute intrathoracic abnormality . Overall similar bilateral opacities to prior examination , though pneumonia is not entirely excluded .