Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: As before , the patient is status post median sternotomy and CABG . The right lung is clear . There is increased opacity at the base of the left lung suggesting atelectasis and a small pleural effusion . A left apical pneumothorax has resolved .
    OUTPUT:
    
Small left pleural effusion and adjacent atelectasis at the left base . Left apical pneumothorax has resolved .