Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is near - complete opacification of the left hemi thorax by a large pleural effusion . Only a minimal portion of the left upper lobe is aerated . The left lower lobe is completely collapsed . The right lung is clear . Assessment of the cardiac and mediastinal contours is difficult due to the large effusion .
    OUTPUT:
    
Large left pleural effusion . Left lower lobe collapse .