Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is opacification of the lower right lung zone , with a lucent crescent just superior to the opacified portion . Pleural effusion tracks behind the aerated upper lobe . There is soft tissue thickening along the right main bronchus . An opacity projects over the left mid lung zone . The mediastinal structures are roughly midline , without apparent volume loss . There is no left pleural effusion . Indentations upon the right lateral aspect of the trachea are noted .
    OUTPUT:
    
1 . Right lower lung zone white out , which might be the result of airway obstruction with post-obstructive pneumonia , collapse ( though lack of volume loss argues against this ) , or paralysis of the right hemidiaphragm . There is a superimposed right pleural effusion / pleural thickening . Additional findings of a mass in the left mid lung zone and probable lymphadenopathy in a paratracheal distribution all argue in favor of a metastatic process . CT is recommended for further evaluation . 2 . The lucent crescent seen adjacent to the lower portion of the aerated left lung is felt unlikely to be free air , though this can be better evaluated with CT .