Abstract
Background Arterial remodeling reflects adaptation of the vessel wall to mechanical and hemodynamic stimuli and contributes to the progression of cardiovascular and cerebrovascular diseases. Tensile stress (TS) is one of the mechanical properties of the artery wall. We sought to investigate the effects of carotid viscoelasticity on its tensile stress (TS) in different age subjects.Methods Forty-five subjects were recruited and divided into the group1 (≥50 years old) and the group2 (<50 years old) according to the median age. The carotid arteries were examined by ultrasonography, including shear wave elastography (SWE), shear wave dispersion (SWD) and radiofrequency (RF) technologies. The values were obtained, including the carotid elastic modulus (SWE R ) and viscous index (SWD R ), as well as the peak and mean TS of the left and right carotid arteries (L-PTS, R-PTS, L-MTS and R-MTS). The correlations between SWE R , SWD R and tensile stress were investigated, respectively.Results In the group1, the carotid arteries had lower SWE R and SWD R than those in the group2 (SWE R , [10.29±9.57] kPa vs. [17.24±14.07] kPa; SWD R [11.99±3.51] (m/s)/kHz vs. [13.97±3.71] (m/s)/kHz, all P values < 0.05). In addition, the R-PTS was also lower in the group 1 ( P <0.05). Pearson correlation analysis showed that the carotid SWE R was positively correlated with tensile stress. R -values for R-PTS, R-MTS, L-PTS and L-MTS were r =0.218, r =0.359, r =0.209 and r =0.369, respectively (all P <0.05). However, the carotid SWD R was not significantly associated with TS.Conclusion Ultrasonic shear wave imaging could be used to quantitatively assess carotid viscoelasticity. The carotid TS was related to its elasticity while little related to its viscosity, suggesting that mechanical properties of the arterial wall might be better revealed.
Noncontact quantitative biomechanical characterization of cardiac muscle using shear wave imaging optical coherence tomography
