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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