Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Large area of opacity persists over the right hemi thorax with increase in aeration over the right lung apex as compared to the prior , and there has been interval decrease in leftward mediastinal shift . The left lung is clear . No definite pneumothorax is seen . The left aspect of the cardiac and mediastinal silhouettes unremarkable . The right aspect is not well assessed due to the large right sided opacity .
    OUTPUT:
    
Large opacity over the right hemithorax persists , with some interval improvement and increase in aeration of the right lung apex status post thoracentesis . However , the majority of the right hemi thorax remains opacified .