Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy and CABG . Heart size remains mild to moderately enlarged with a left ventricular predominance . The aorta is unfolded . Mediastinal and hilar contours are unremarkable . Pulmonary vasculature is normal . Linear opacities in the left lower lobe likely reflect subsegmental atelectasis . No focal consolidation , pleural effusion or pneumothorax is present . No displaced fracture is visualized .
    OUTPUT:
    
Subsegmental left lower lobe atelectasis . No displaced fracture identified . If there is continued concern for rib fracture , consider a dedicated rib series .