Accurate and nondestructive measurement of different lipoproteins simultaneously in carotid plaque in stroke patients using near-infrared (IR) imaging spectrometry seems possible for research. The lipoprotein composition of the plaque appears to have an impact on the outcome of the disease process. Carotid atherosclerosis without associated thrombosis is frequently a benign disease that is asymptomatic, although TIAs may be present in other cases. Many patients with carotid atherosclerosis can be treated surgically by endarterectomy with high initial success and favorable long-term prognosis. The acute manifestation of carotid atherosclerosis - stroke - arises when thrombus or ulceration develop. This potentially life-threatening complication probably develops at the site of plaque fissure or rupture. Recent research by others indicates that it is not the severity of stenosis (plaque volume) that determines the outcome: it is the type of stenosis (plaque chemical composition) and the extent of collateral growth.