Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since the prior study , there has been interval improvement in aeration of the right lung , particularly in the infrahilar region . Persistent opacification in the suprahilar left lung is compatible with known mass , with postobstructive atelectasis . A small pleural effusion on the left persists . There is no pneumothorax or overt pulmonary edema . The heart size is stable . Dense atherosclerotic calcifications are noted within the aortic arch and descending thoracic aorta .
    OUTPUT:
    
1 . Right lower lobe pneumonia has improved since the prior study . 2 . Left suprahilar mass and left pleural effusion persist .