Apolipoprotein B (apoB) levels (which encompass all atherogenic lipoproteins, including LDL), Lp(a) levels, and carotid IPH are associated with both first-ever and recurrent ischemic stroke. This cohort research project is to analyze: 1. Among patients with carotid artery atherosclerosis (stenosis 30-99%), to compare patients with and without IPH, as assessed by magnetic resonance (MR)-Plaque Imaging, in terms of apoB, Lp(a) levels and other cardiovascular risk factors. (IPH is a strong morphological sign of plaque vulnerability / instability and a strong marker of consecutive atheroembolic events). 2. Among patients with carotid artery atherosclerosis (stenosis 30-99%), to assess the risk of first-ever ischemic stroke in relation to apoB, Lp(a) levels, and presence of IPH, after adjusting for the cardiovascular factors (understanding this association can inform primary prevention). 3. Among patients with carotid artery atherosclerosis (stenosis 30-99%) with an ipsilateral ischemic stroke at baseline, to assess the risk of recurrent ipsilateral ischemic stroke in relation to apoB, Lp(a) levels, and presence of IPH, after adjusting for the cardiovascular factors. There will be a sensitivity analysis to assess if the association between Lp(a) and recurrent stroke is stronger in patients \<60 years of age. (understanding this association can inform secondary prevention). For the first and second aim, there will be a cross-sectional, case-control analysis. For the third aim, i.e. assessing recurrent ischemic stroke, there is prospective follow-up of at least 3 months up to 45 months.