Coloured X-ray of the pelvis of a 79 year old woman, showing numerous atheromatous plaques (white) lining the femoral (thigh) arteries (inside of thigh bones at right and left). Atherosclerosis is a condition in which an artery wall thickens as a result of accumulations (atheromas) of fatty materials such as cholesterol. These atheromas have calcified and hardened.