Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest are obtained . The previously noted right IJ central venous catheter has been removed . Midline sternotomy wires and mediastinal clips are stable . There is slight elevation of the left hemidiaphragm with left basilar atelectasis with overall improvement in left basilar aeration compared with prior study . The right lung is clear . Heart is top normal . Mediastinal contour is stable . Bony structures are intact . Right AC joint arthropathy is again noted . No free air below the right hemidiaphragm .
    OUTPUT:
    
Persistent left lung base atelectasis . Otherwise , unremarkable .