Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Status post median sternotomy and CABG . Mild enlargement of the cardiac silhouette is re - demonstrated . Atherosclerotic calcifications are noted at the aortic knob . Widening of the superior mediastinal contour may be due to the presence of mediastinal fat and slightly low lung volumes . There is crowding of bronchovascular structures likely attributable to low lung volumes without overt pulmonary edema . Persistent small to moderate size left pleural effusion is present with left basilar opacification likely reflective of compressive atelectasis . Mild interstitial abnormality in the right lower lobe likely reflects chronic changes and atelectasis . No pneumothorax . No acute osseous abnormalities detected .
    OUTPUT:
    
1 . Persistent small to moderate size left pleural effusion with left basilar opacification , likely compressive atelectasis . 2 . Low lung volumes . Mild interstitial abnormality in the right lung base may reflect chronic changes and atelectasis .