Natural History of Carotid Plaque as Determined by 3D Ultrasound

"Carotid artery ultrasound will be used to:~Determine plaque presence and plaque burden Presence of stenosis~Additionally, Carotid Intima-Media Thickness (IMT) will be measured and aortic diameter will be measured by abdominal aortic ultrasound scanning.~Ultrasound of the Abdominal Aorta will be used to determine the presence and severity of stenosis or aneurism."