Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Following pigtail catheter drainage , there is improved aeration of the right lung with persistent partial opacification secondary to a decreased moderate pleural effusion . Diffuse right lung airspace opacities are now visible . The left lung remains clear . There is no pneumothorax . The heart and mediastinum can not be accurately assessed .
    OUTPUT:
    
Decreased moderate right pleural effusion following pigtail catheter drainage . Right lung airspace opacities may be due to pulmonary hemorrhage or edema . A CT scan would be helpful in determining whether there is a central mass and to assess airway patency , and should be done with intravenous contrast .