Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Median sternotomy wires are intact . Replaced aortic valve is in appropriate , unchanged position . Normal , postoperative cardiomediastinal silhouette . Slight interval improvement in retrocardiac opacity suggests improving left basilar atelectasis . Crescentic lucency beneath the right hemidiaphragm on the frontal view and presence ___ ___'s sign on the left lateral decubitus view are consistent with a small amount of pneumoperitoneum .
    OUTPUT:
    
Small pneumoperitoneum . Recommend dedicated abdominal imaging for further evaluation .