Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes with interval improvement in pulmonary edema . Unchanged cardiomegaly . Aortic knuckle calcification . No pleural effusion . Stable sternotomy sutures .
    OUTPUT:
    
Improvement in pulmonary edema and left pleural effusion compared to ___ . Cardiomegaly and low lung volumes persist .