FINDINGS:
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 4.7cm 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.

IMPRESSION:
1.  No acute cardiopulmonary process.  
 
 2.  Stable apparent dilation of the aortic arch is likely artifactual.  Chest
 CTA may be considered if symptoms persist.