International journal of stroke : official journal of the International Stroke Society
-
Intima-media thickness (IMT) has been measured for over 20 years, and is widely regarded as a surrogate for atherosclerosis. However, in the carotid arteries atherosclerosis is focal, manifesting as plaques. IMT is often measured deliberately where no plaque exists, or multiple measurements may be averaged, including only one or two that intersect plaque. ⋯ While 3-D ultrasound requires special equipment, total plaque area can be measured using the same equipment as IMT. Because plaque and IMT are biologically and genetically distinct entities, representing different phenotypes of atherosclerosis, both should be measured in any situation where IMT is measured, with the exception of studies in children too young for the occurrence of plaque. IMT should not be called 'atherosclerosis': the phenotype being assessed should be specified.