An abdominal aortic aneurysm (AAA) is a dilation of the abdominal aorta, which is often asymptomatic and diagnosed by chance. If an AAA is not treated, it may rupture and cause a life-threatening haemorrhage. Nevertheless, surgical repair of the aneurysm is not without risks and is associated with high morbidity and mortality rates. Nowadays surgery is recommended when the maximum diameter of the AAA is larger than 5.5cm, however a reliable rupture predictor does not exist. In order to improve the prediction of AAA rupture, vessel wall properties like distensibility (D) and Young's modulus (E) have been investigated. MRI and CT are frequently used to study AAA. However, in this study 2D ultrasound (US) is used to determine mechanical properties of the vessel wall, since US is more suitable for follow-up as it is faster and less expensive.