Quantifying carotid plaque component regional strain using ultrasound elastography and its association with blood...

Cardiovascular and cerebrovascular diseases are leading causes of mortality worldwide, with carotid plaque rupture being a critical pathogenic mechanism. While ultrasound elastography can assess the mechanical properties of plaque, the dynamic strain of specific plaque component regions and its correlation with blood pressure are not well characterized. This pilot study retrospectively analyzed carotid ultrasound elastography images from 11 patients. Image preprocessing involved wavelet Bayesian denoising and enhanced correlation coefficient registration to minimize motion artifacts. Dense optical flow was computed using the Farneback algorithm, and regional strain was derived through spatial gradient extraction and least-squares fitting. Our analysis revealed substantial heterogeneity in strain among plaque component regions. The mean inter-frame strain ranged from 0.0007 to 0.0045, the maximum inter-frame strain from 0.0025 to 0.0454, and the maximum cumulative strain over the cardiac cycle from 0.0078 to 0.1948. Diastolic blood pressure showed positive correlations with the mean inter-frame strain, the maximum cumulative strain and the maximum inter-frame strain of plaque component regions (r = 0.5121, 0.4606, 0.3977), the pulse pressure demonstrated moderate negative correlations with all three strain indices (r = -0.5043, -0.4757, -0.4650), showing statistical significance even with a small sample size. These exploratory findings suggest that blood pressure may influence the mechanical environment of plaque component regions. This pilot study validates the feasibility of dynamic strain quantification for plaque component regions using ultrasound elastography. The identified association with blood pressure provides new directions for investigating mechanical factors in plaque progression and developing non-invasive risk prediction models.