Histological Validation Of Carotid Plaque Composition In Preoperative Imaging

Patients scheduled for carotid endarterectomy undergo preoperative imaging to assess vulnerable plaque. The imaging modalities include (in various combinations at different study sites) 3-dimensional ultrasound, PET/CT imaging with fluorodeoxyglucose, MRI (3T)with gadolinium, and contrast ultrasound for assessment of neovascularity of plaques. At surgery the carotid endarterectomy is carried out with en bloc removal of the specimen, which is scanned and stained and assembled into 3D histology.

Detailed Description: Patients will undergo 3D U/S and at least one other imaging method, PET/CTA or MRI, preoperatively. At some sites, some patients will also have an ultrasound with microbubbles. Following surgery, the carotid specimens will be transported to a central pathology lab for microcomputed tomographic imaging and further study. At some sites patients will have a follow-up 3D U/S approximately 1 year after surgery to determine progression of plaque. CAIN-2 sub-studies: Eligible patients may be enrolled into one of the following sub-studies: 1. CAIN-2 NaF pilot Characterizing Atherosclerotic Plaque with Sodium Fluoride Positron Emission Tomography- A Sub-Study of the Canadian Atherosclerosis Imaging Network (CAIN Project 2), - patients undergo sodium fluoride (NaF) PET/CT with CTA instead of FDG PET/CT preoperatively. All other imaging and study procedures are carried out as per the CAIN-2 study. Recruitment for this pilot study is complete. 2. CAIN-2B Atherosclerotic plaque imaging using NaF and FDG imaging: Validation and Evaluation of Disease Progression. A sub-study of the Canadian Atherosclerosis Imaging Network (CAIN-2) Histopathology Validation study - patients undergo both NaF and FDG PET/CT preoperatively. All other imaging and study procedures are carried out as per the CAIN-2 study. A total of 45 patients will be enrolled in this sub-study. Eligibility criteria for the sub-studies is identical to the CAIN-2 criteria.