Modelling the stresses in an abdominal aortic aneurysm. This dangerous condition is a weakening of the wall of the large artery that travels down the body from the heart. Once the wall is weakened it is liable to rupture under the influence of factors such as high blood pressure. The areas of greatest stress in this silicon model are highlighted in red. The major cause of abdominal aortic aneurysms is hardening of the arteries (atherosclerosis) where arteries become blocked with plaque. Measuring aneurysm stress may help vascular surgeons to identify patients at risk in order to offer them early surgery to prevent such a disaster. The spots on the image show tiny reflective markers that are part of the measurement techniques. Biomedical Image Awards 2006.