Alternative Diagnosis

If aortic dissection is not the cause of the patient’s symptoms an alternative diagnosis may be made with CT that would not be made with TOE or aortography. For example:

• Perforated oesophagus – air may be demonstrated within the mediastinum
• Vertebral wedge fractures
• Air in the peritoneum suggesting a perforated hollow viscus
• Leaking AAA (Fig 1)
• Oedematous pancreas suggesting pancreatitis

The sensitivity of CT detection for AAD is not yet 100%. It may miss a dissection if there is complete thrombosis of one lumen or if there is similar opacification of both the true and false lumens.

Also, intramural haematoma may be missed as the findings are often subtle and only evident on pre-contrast images.

The CT shows a ruptured abdominal aneurysm (click on the image to enlarge).