Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Right minimal residual apical pneumothorax is unchanged since this morning , measuring 7 mm , but significantly improved since ___ . Pigtail is unchanged in upper hemithorax . Left upper lobe atelectasis has completely resolved . There is no pleural effusion . The mediastinal and cardiac contours are within normal limits .
    OUTPUT:
    
Right residual pneumothorax is minimal and significantly improved since ___ .