Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared to the most recent previous exam , there is persistent mild pulmonary edema with upper zone vascular redistribution , perihilar haziness and vascular indistinctness , slightly worse in the interval . Heart size remains mild to moderately enlarged . The aorta is calcified diffusely . Mediastinal contours are unchanged with multiple clips again noted about the superior mediastinum . More focal opacity in the left lung base towards the costophrenic angle may reflect an area of atelectasis with small pleural effusion , however infection is not excluded . No pneumothorax is clearly identified . Multilevel degenerative changes are noted in the thoracic spine .
    OUTPUT:
    
Mild pulmonary edema , slightly worse in the interval . Focal opacity in the left lung base towards the costophrenic angle may reflect an area of atelectasis with small pleural effusion , however infection is not excluded .