Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Again , there is a large left - sided pleural effusion with significant adjacent atelectasis and partial left lower lobe collapse . There is no right - sided pleural effusion or pneumothorax identified . The upper lung fields are grossly clear bilaterally . No appreciable mediastinal shift is identified . The cardiac size is difficult to measure accurately given the obscuration of the left heart border by the large effusion .
    OUTPUT:
    
Essentially unchanged appearance of a large left pleural effusion with significant adjacent atelectasis .