Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Left apical pneumothorax has improved from 8 mm to 3 mm . Small left pleural effusion with air - fluid level has also improved . The right lung is unremarkable . Left lower lung atelectasis is unchanged . Mediastinal and cardiac contours are normal .
    OUTPUT:
    
Improvement of the left minimal pneumothorax and small pleural effusion .