Motion synchronisation patterns of the carotid atheromatous plaque from B-mode ultrasound
Spyretta Golemati1,2, Eleni Patelaki3,4, Aimilia Gastounioti5
1Biomedical Simulations and Imaging Lab., School of Electrical and Computer Engineering, National Technical University of Athens, Athens, Greece. sgolemati@med.uoa.gr.
Insights
Asynchronous carotid plaque motion, quantified using ultrasound, correlates with plaque vulnerability and stroke risk. This study reveals distinct phase shifts indicating higher risk in echolucent, high-stenosis plaques.
Area of Science:
- Cardiovascular imaging
- Biomedical engineering
- Stroke research
Background:
- Asynchronous movement of carotid atheromatous plaque has been linked to stroke risk.
- Quantitative estimation of this asynchronous motion and its association with plaque vulnerability is lacking.
Purpose of the Study:
- To quantitatively estimate plaque motion synchronisation patterns using cross-correlations of displacement waveforms.
- To investigate the association between asynchronous plaque motion and plaque vulnerability characteristics.
Main Methods:
- Analysis of 135 carotid plaques from 77 subjects using B-mode ultrasound.
- Estimation of synchronisation patterns and phase shifts between different plaque tissue areas and arterial diameter.
- Classification of phase-shift-based features using Random Forests.
Main Results:
- Plaque radial deformation was approximately 50% synchronized with arterial diameter (mean phase shift 0.4 s).
- Within plaques, mean phase shifts were 0.2 s (radial) and 0.3 s (longitudinal) between top/bottom surfaces, with ~80% synchronisation.
- Random Forest classification achieved AUC scores of 0.79-0.90 for plaque characteristics.
- Echolucent, high-stenosis, and high-risk plaques showed greater phase shifts in radial displacements.
Conclusions:
- Asynchronous plaque motion can be quantitatively estimated and is associated with plaque vulnerability.
- Phase shift analysis of plaque kinematics offers a promising tool for assessing stroke risk.
- Findings support the utility of plaque motion analysis in understanding vulnerable plaque characteristics.
Abstract:
Asynchronous movement of the carotid atheromatous plaque from B-mode ultrasound has been previously reported, and associated with higher risk of stroke, but not quantitatively estimated. Based on the hypothesis that asynchronous plaque motion is associated with vulnerable plaque, in this study, synchronisation patterns of different tissue areas were estimated using cross-correlations of displacement waveforms. In 135 plaques (77 subjects), plaque radial deformation was synchronised by approximately 50% with the arterial diameter, and the mean phase shift was 0.4 s. Within the plaque, the mean phase shifts between the displacements of the top and bottom surfaces were 0.2 s and 0.3 s, in the radial and longitudinal directions, respectively, and the synchronisation about 80% in both directions. Classification of phase-shift-based features using Random Forests yielded Area-Under-the-Curve scores of 0.81, 0.79, 0.89 and 0.90 for echogenicity, symptomaticity, stenosis degree and plaque risk, respectively. Statistical analysis showed that echolucent, high-stenosis and high-risk plaques exhibited higher phase shifts between the radial displacements of their top and bottom surfaces. These findings are useful in the study of plaque kinematics.
