Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is nearly complete opacification of the hemithorax but without substantial net shift of mediastinal structures . This may reflect a large pleural effusion with associated atelectasis or pneumonia but is incompletely characterized . Patchy opacification is noted in the right mid to lower lung with a suspected small pleural effusion on the right . The pulmonary vascularity in the right lung is mildly prominent , suggesting mild fluid overload .
    OUTPUT:
    
Nearly complete opacification of the left hemithorax with balanced mass effect , suggesting a large pleural effusion among other potential causes , including the possibility of malignancy . Chest CT may be useful to evaluate further if clinically indicated .