New Technologies to Determine Carotid Plaque Vulnerability

Hypothesis: Identification of vulnerable atherosclerotic plaques (with or without neovascularization) using carotid CEUS is an independent predictor of MACE (over clinical risk factors, stress echo wall motion results, and carotid ultrasound two-dimensional speckle tracking strain indices). Primary Aims: 1. Evaluate the diagnostic role of carotid CEUS and two-dimensional speckle tracking strain imaging for detection of carotid plaque: * To determine the feasibility and safety of Carotid CEUS and Two-dimensional speckle tracking strain imaging SE . * To determine if carotid CEUS and two-dimensional speckle tracking strain imaging findings are associated with coronary angiographic results in those patients undergoing clinically indicated cardiac catheterization. * To determine the diagnostic accuracy of CEUS in identifying a vulnerable atherosclerotic plaque and neovascularization compared to carotid MRI, in a subset of patients. 2. Evaluate the prognostic role of carotid CEUS and two-dimensional speckle tracking strain imaging for prediction of MACE: * To determine if plaque identification (with or without neovascularization) on Carotid CEUS SE can improve the overall prediction of MACE over stress echo results alone * To determine if Carotid ultrasound two-dimensional speckle tracking strain indices can improve the overall prediction of MACE over stress echo results alone. * To determine if the detection of plaque neovascularization by Carotid CEUS is an independent predictor of MACE (over clinical risk factors, stress echo wall motion results, and carotid ultrasound two-dimensional speckle tracking strain indices).