Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well expanded . An opacity in the left mid lung is crescentic in shape . The cardiomediastinal silhouette , hilar contours and pleural surfaces are normal . There is a healed right rib fracture .
    OUTPUT:
    
Crescentic opacity in the left mid lung is likely atalectasis but should be followed up with chest radiograph . Updated results were telephoned by ___ to ___ at 9 : 15 am , ___ , 45 minutes after discovery .