Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest were provided . Midline sternotomy wires , mediastinal clips , prosthetic cardiac valve and abandoned epicardial pacing leads are noted , not significantly changed . There are tiny bilateral pleural effusions . There is retrocardiac opacity which appears similar to prior exam and could represent atelectasis versus pneumonia . No pneumothorax is seen . No overt signs of edema . Cardiomediastinal silhouette is stable . Bony structures are essentially stable . Partially imaged vascular stent is noted in the upper abdomen , compatible with AAA repair .
    OUTPUT:
    
Persisting small bilateral effusions and retrocardiac opacity which could represent atelectasis or pneumonia .