Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Normal cardiomediastinal and hilar contours . Clear lungs . Interval resolution of wedge - shaped opacity at the left base . Small , linear densities at the left base likely reflect subsegmental atelectasis . No pneumothorax or pleural effusion .
    OUTPUT:
    
Interval resolution of wedge - shaped opacity at the left base .