Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Right - sided moderate pleural effusion . The lung volumes are low with crowding of the bronchovascular markings . Mild cardiomegaly with prior aortic valve repair , median sternotomy and dual lead pacer in similar position . The left lung is relatively clear .
    OUTPUT:
    
Moderate right - sided pleural effusion .