Ultrasound Elastography: another piece in the puzzle of carotid plaque vulnerability?

Recent literature has shown that various carotid plaque features, other than stenosis, contribute to plaque vulnerability. Features such as surface morphology and plaque composition with distinct components (e.g. intraplaque hemorrhage, lipid core) have been associated with the increased risk of future cerebrovascular events. Ultrasonography constitutes the first line modality for the assessment of carotid disease and has traditionally been used to grade stenosis with high accuracy. Recenttechnological advances such as contrast-enhanced ultrasound and elastography increased the diagnostic yield of ultrasound in assessing the morphology of carotid plaques. The purpose of this review is to present the available literature on ultrasound elastography of the atherosclerotic carotid. Strain and shear wave elastography allow for the characterization of plaque components, thus indicating its nature and importantly, the plaque's vulnerability. Shear wave elastography indices appear morerobust than Strain indices. Overall, elastography is a feasible method to distinguish vulnerable carotid plaques. There is, however, a need for larger and longer prospective controlled clinical studies in order to validate elastography as an imaging modality used for the detection of unstable carotid plaques.