The possibility to identify the risk of rupture of a carotid plaque will have tremendous impact in clinical decision making. A vulnerable plaque is considered to have a large lipid rich necrotic core (LRNC), a thin fibrous cap, the presence of inflammatory cells, intraplaque haemorrhage and/or neovascularisation (vasa vasorum). The investigators aim to validate imaging of plaque vulnerability with histology. Previous studies have evaluated the use of imaging to assess carotid plaque vulnerability, mostly showing a good correlation between imaging and histology and/or clinical characteristics. However, they have focused on single modalities, (magnetic resonance imaging [MRI], multidetector-row computed tomography (MDCT), ultrasonography (US) or transcranial Doppler (TCD), and have used relatively small cohorts