First, to establish a comparison of the pathophysiology of carotid atherosclerosis and the genetic and environmental variables that cause those plaques to become symptomatic. Second, to differentiate between vulnerable plaque and other types of plaque using ultrasound elastography, MRI data, trans-cranial doppler along with RF (radio frequency) analysis of back-scattered ultrasonic echoes.

This is a multi-investigator study based on the pathophysiology of carotid atherosclerosis and the variables that cause certain plaques to become symptomatic.Patients enrolled in this study will be those patients undergoing a carotid endarterectomy. This will include both symptomatic and asymptomatic patients, and there are a variety of atherosclerotic risk factors representing this patient population.Patients may or may not have had strokes or transient ischemic attacks (TIAs).Pre-operatively patients will be reviewed for their medical history and atherosclerotic risk factors. Plaque removed during routine carotid endarterectomy will be examined for study purposes.

Inclusion Criteria:

• Male and Female patients aged 18-80 presenting for carotid endarterectomy

Exclusion Criteria:

• Patients not felt suitable for carotid endarterectomy and those with impaired decision-making capacity

Patients undergoing carotid endarectomy