Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient has had median sternotomy with intact and aligned sternotomy wires . Lung volumes are low . Moderate right has slightly increased , and the small left pleural effusion has slightly decreased post pigtail catheter drainage . A drainage catheter is partially imaged overlying the right costophrenic angle . Airspace disease or malignancy at either lung base can not be excluded . There is no pneumothorax .
    OUTPUT:
    
Slightly increased moderate right pleural effusion . Decreased small left pleural effusion following pigtail catheter drainage . Airspace disease or malignancy at either lung base can not be excluded . A contrast - enhanced chest CT may be obtained for further evaluation .