Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared to chest radiograph from ___ , lung volumes remain low . Patient is status post median sternotomy and CABG . No central vascular congestion or pulmonary edema is identified . No focal consolidation , pleural effusion or pneumothorax . Minimal bibasilar atelectasis is unchanged . Moderate cardiomegaly is unchanged . Extensive atherosclerotic calcification of the aorta is present . Moderate degenerate changes of the visualized thoracolumbar spine with unchanged compared compression deformity at the thoracolumbar junction . Surgical clips in the right upper quadrant suggest prior cholecystectomy .
    OUTPUT:
    
1 . No evidence of pneumonia . 2 . Persistent low lung volumes with minimal bibasilar atelectasis .