Article:

A comparison of the approaches to assess the abdominal aortic stiffness using M-mode ultrasonography, tissue tracking and strain rate imaging

Abstract Introduction: Which kind of ultrasound imaging technique is suitable for the assessment of the abdominal aortic stiffness are seldom reported. The purposes of this study were to explore a reliable method to evaluate the abdominal aortic stiffness in patients with hypertension among the following ultrasound imaging techniques: M-mode ultrasonography (M-mode), tissue tracking and strain rate imaging. Methods: Fifty patients with hypertension and fifty age and sex-matched healthy volunteers were involved in this study. The displacement (d), the peak strain (ε) and the peak strain rate (s) were obtained from the long-axis images of the abdominal aorta using tissue tracking and strain rate imaging, respectively. The pressure strain elastic modulus (Ep), β stiffness index and distensibility were calculated according to the conventional formulas using M-mode combined with the blood pressure. Results: Compared to the normal subjects, the difference between systolic diameters and diastolic diameters (Δdiameter), the displacement of posterior wall (d-posterior), the difference of the displacement between anterior and posterior wall (Δ displacement), and the distensibility decreased and the Ep and β stiffness index increased in the hypertension patients There were no significant differences between the patients with hypertension and the normal subjects according to the ε, s. Among Δdiameters, d-posterior, Δdisplacement, the ε and s, only Δdiameters significantly correlated with the Ep, β stiffness index and the distensibility in hypertension patients. Conclusions: Strain rate imaging cannot sensitively discriminate the difference of the abdominal aortic stiffness between patients with hypertension and the normal subjects. M-mode ultrasonography is still a classical method for accessing the aortic elasticity. Keywords: Abdominal aortic elasticity; Hypertension M-mode ultrasonography; Strain rate imaging; Tissue tracking.