Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . Vague nodular opacity projecting over the left mid lung as on prior chest radiograph has been previously characterized as a bone island within the left posterior sixth rib and is also seen on today 's exam . Aside from this , the lungs are clear without focal consolidation , effusion , or pneumothorax . The cardiomediastinal silhouette is normal . Imaged osseous structures are intact . No free air below the right hemidiaphragm is seen .
    OUTPUT:
    
No acute findings .