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.
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Keywords: abdominal aortic elasticity; hypertension M-mode ultrasonography; strain rate imaging; tissue
tracking.
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