Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared with ___ , interval slight decrease in the large left pleural effusion with associated improved aeration in the left upper lung . A left - sided chest tube is in unchanged location . The right lung is clear . There is no substantial right - sided effusion . There is no pneumothorax or mediastinal shift . The visualized portions of the cardiomediastinal silhouette are normal .
    OUTPUT:
    
Slight interval decrease in left pleural effusion .