Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral radiographs of the chest were acquired . The patient is status post midline sternotomy , with intact wires . Multiple surgical clips are seen throughout the mediastinum , compatible with prior CABG . There is minimal left lower lobe scarring / atelectasis , unchanged . The lungs are otherwise clear . The heart size is normal . The descending aorta is tortuous , unchanged . The mediastinal contours are otherwise normal . There are no pleural effusions . No pneumothorax is seen . Multilevel degenerative changes of the thoracolumbar spine are noted .
    OUTPUT:
    
No acute cardiac or pulmonary process .