Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are clear . A rounded opacity in the left upper thorax likely represents costochondral calcification at the tip of the left first rib . The hilar and cardiomediastinal contours are normal . There is no pneumothorax . There is no pleural effusion . Pulmonary vascularity is normal .
    OUTPUT:
    
No evidence of acute cardiopulmonary process .