Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since the prior exam , the pulmonary edema has improved , and is now mild . Bibasilar atelectasis , more pronounced on the left than the right , is not significantly changed . There is no new opacity to suggest pneumonia . There is no pleural effusion or pneumothorax . Calcifications are noted at the aortic arch . Moderate cardiomegaly is unchanged . There is no free air below the hemidiaphragms .
    OUTPUT:
    
Mild pulmonary edema , improved from the prior exam . No pleural effusion .