Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since the prior exam , the lung volumes are lower . Opacities at the bilateral bases are most compatible with atelectasis . There is no pulmonary edema , pleural effusion , or pneumothorax . The aorta is tortuous with calcifications along the aortic arch . It is unchanged in appearance since the prior exam . The heart is mildly enlarged .
    OUTPUT:
    
1 . Bibasilar atelectasis . 2 . Mild cardiomegaly . 3 . Unchanged appearance of the tortuous aorta .