Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post median sternotomy and CABG . The heart remains moderately enlarged . Mediastinal and hilar contours are relatively unchanged . There is no pulmonary edema . Persistent left basilar opacification with small left pleural effusion is similar compared to the prior exam . Aeration of the right lung base is improved . There is no pneumothorax . Previously seen pneumoperitoneum appears resolved .
    OUTPUT:
    
Persistent left basilar opacity likely reflective of atelectasis with adjacent small left pleural effusion . No subdiaphragmatic free air .