Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Right - sided IJV CVP in situ with the tip in the mid SVC . Post mechanical AVR changes . Cardiomediastinal shadow essentially unchanged . Increased density projecting over the left lower lobe most likely representing atelectasis . Small bilateral pleural effusions . No pneumothorax .
    OUTPUT:
    
Persistent left lower lobe atelectasis and small bilateral pleural effusions . No pneumothorax .