Introduction: Carotid atherosclerosis is a risk factor for ischaemic stroke. There is increasing interest in identifying and characterising high-risk unstable carotid plaques. Shear wave elastography (SWE) imaging is a new method of quantifying tissue stiffness with potential to provide additional information to help identify the unstable plaque and improve patient selection for surgical treatment. We evaluate this technique in assessing stiffness of carotid artery plaques by correlating histology findings to Young’s modulus (YM) measured using SWE.

Method: 5 symptomatic patients undergoing carotid endarterectomy were recruited into the study. Prior to surgery, each patient underwent carotid ultrasound scan using SWE and B-mode. A longitudinal section of the carotid plaque was imaged. The YM of the plaques was compared to echogenicity and histological classification based on stability of the excised plaque.

Results: All patient presented with >80% stenosis in either of the internal carotid arteries. Mean YM was 108 (52–195) kPa. All five plaques varied in echogenicity classification. On histology, 2 plaques were ‘probably or definitely’ unstable and 2 were probably stable (Fig.1). There was better correlation between YM and histology finding compared to echogenicity.

Figure 1

Patient with echogenic plaque on B-mode, YM of 66Kpa and histology classification of definitely unstable.

Conclusion: This present insight into the role of novel ultrasonic based technique in providing further information in characterising carotid plaque properties which may be of value in identifying vulnerable plaques.