Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest radiographs were obtained . The lungs are well expanded and clear . There is no focal consolidation , effusion , or pneumothorax . The aortic arch appears enlarged up to 4 .7 cm in diameter . The size is similar to the appearance on chest x-ray ___ . The subsequently acquired chest CTA on ___ showed a normal caliber aorta . There are no other abnormal cardiac and mediastinal contours .
    OUTPUT:
    
1 . No acute cardiopulmonary process . 2 . Stable apparent dilation of the aortic arch is likely artifactual . Chest CTA may be considered if symptoms persist .