investigations

Last reviewed 01/2018

A number of imaging techniques are available for the assessment of AAA.

  • ultrasonography
    • non invasive, low cost method with the sensitivity and specificity close to 100%
    • measures the size of the aorta in longitudinal as well as in anteroposterior and transverse directions
    • modality of choice for initial assessment, follow up, screening and surveillance
    • should have a low threshold for arranging abdominal ultrasonography in patients at risk. 
  • CT
    • can visualise
      • the proximal neck (the transition between the normal and aneurysmal aorta)
      • any extensions of the aneurysm (to the iliac areries)
      • patency of visceral arteries
      • the presence of blood within the thrombus (crescent sign) - is considered a predictive marker of imminent rupture
    • helical CT and CT angiography can provide additional anatomical details - useful if an endovascular procedure is considered
  • resonance angiography (MRA)
    • safer than conventional arteriography since it does not use nephrotoxic contrast material (1,2)
  • plain radiography
    • calcified aneurysmal wall may be seen in some cases

In addition, baseline laboratory assessment for cardiovascular risk factors could be carried as well.  

In the acute presentation of a leaking or ruptured abdominal aortic aneurysm, the admitting doctor should move immediately from the clinical diagnosis to the emergency management

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