Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is moderately enlarged . The main pulmonary artery contour is markedly enlarged , which raises concern for underlying pulmonary hypertension . Vascular calcifications are noted along the aortic arch . Aside from a similar streaky atelectasis at the left lung base , the lungs appear clear . There is no evidence for congestive heart failure . There are no pleural effusions or pneumothorax . Mild spinal degenerative changes are similar .
    OUTPUT:
    
No evidence of acute disease or significant change . Enlargement of the main pulmonary artery , worrisome for pulmonary arterial hypertension .