Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Normal mediastinal and hilar contours . Normal heart size . Small to moderate left apical pneumothorax without evidence of tension . Fracture through the lateral aspect of the left posterior eighth rib . Opacity at the left base may reflect left lower lobe atelectasis .
    OUTPUT:
    
1 . Small to moderate left pneumothorax without evidence of tension . 2 . Left posterior eighth rib fracture . 3 . Probable left lower lobe atelectasis .