Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy . Heart size is borderline enlarged . Mediastinal and hilar contours are unremarkable . The pulmonary vascularity is not engorged . Linear opacities in the left lung base likely reflect subsegmental atelectasis . Blunting of the left costophrenic angle is likely indicative of a small pleural effusion . No pneumothorax or right - sided pleural effusion is present . No acute osseous abnormalities are detected .
    OUTPUT:
    
Subsegmental atelectasis in the left lung base . Small left pleural effusion .