3D/4D Ultrasound Contrast Enhanced Imaging (CEUS) for Carotid Plaque Vulnerability

Inclusion Criteria: * Adult subjects with known carotid artery disease will be included. * Subject must be able and willing to comply with study procedures and provide a signed and dated informed consent including consent for 3 year annual follow up. * Subjects will be screened by asking each study subject if they have known or suspected hypersensitivity to any of the components of Optison, blood, blood products of albumin. In addition, each study subject will be asked if they have a right to left or bi-directional or transient right to left cardiac shunts. If any of the above questions are answered in the positive, the patient will not be eligible for inclusion in the study. Exclusion Criteria: * Female subjects of child bearing potential will be excluded. * The subject presents any clinically active, serious, life-threatening disease, with a life expectancy of less than 1 month or where study participation may compromise the management of the subject or other reason that in the judgment of the investigator makes the subject unsuitable for participation in the study. * History of acute occlusion requiring medical intervention of any artery (including aorta) within 6 months of consent. * Has a known or suspected hypersensitivity to any of the components of Optison, blood, blood products, or albumin. * Has known right to left, bi-directional or transient right to left cardiac shunts. * Any known contra-indications as listed on the current Optison package insert.