Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared with the prior chest radiograph , the previously described right hilar mass is persistently surrounded by a parenchymal opacity with air bronchograms , grossly unchanged in appearance . These findings are suggestive of postobstructive pneumonia . The cardiac silhouette is unchanged . The left lung is clear .
    OUTPUT:
    
No change in the appearance of the postobstructive pneumonia of the right upper lobe since the radiograph of ___ . The left lung is clear .