Ischemic stroke is a leading cause of death and disability worldwide. Atherosclerosis, responsible for the 20% of ischemic strokes, is characterized by lipid accumulation in the artery wall that leads to chronic inflammation, cell proliferation and ultimately to vessel stenosis. One of the main features related to plaque progression and vulnerability is inflammation. Positron emission tomography with 18-fluorodeoxyglucos (18-FDG PET) allows an accurate quantification of plaque inflammation and it has been proved its usefulness in predicting early stroke recurrences. The investigators aim to test how modifiable vascular risk factors influence plaque inflammation assessed by 18-FDG PET. In addition, investigators will assess the association of this inflammation and circulating endothelial progenitor cells