Radiological appearance of an aneurysm of the ascen. aorta

• prominent ascending aorta in a young patient (patient less than 40 years of age)
  
  
• the descending aorta (assessed on lateral film) has a disproportionately mild or even absent prominence
  
  
• wide aortic arch
  
  
• clues to the cause of an aneurysm include:
  
  
• mild and generalized dilatation occurs with hypertension
  
  
• in Marfan's syndrome - aneurysms generally occur in the ascending aorta and usually most marked in the region of the aortic sinuses. They result in aortic regurgitation
  
  
• syphilis - aneurysms affect the ascending aorta. They are characterised by continuous, thin, curvilinear calcification (1)
  
  
• atheromatous aneurysms - calcification consists of irregular, interrupted plaques. These forms of aneurysm are most common in the descending aorta

Reference:

• Hampton J (1993). The patient with chest pain and breathlessness. Medicine International, 21(8), 289-91.