Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac silhouette is borderline enlarged . Again noted is enlargement of the main pulmonary artery , possibly due to pulmonary arterial hypertension . Opacity is seen at the right lung base , which may represent atelectasis . No definite pleural effusion or pneumothorax is identified .
    OUTPUT:
    
Right basilar atelectasis .