Aortic stiffness assessment with ultrafast ultrasound imaging in case of bicuspid aortic valve

Abstract

To develop specific aortic sequences in ultrafast ultrasound imaging (UF) to provide access to the aortic MRSD. We used a phased array probe (Supersonic Imagine©) and dedicated sequences at 2000 frames/s developed in the laboratory. Data were analyzed with a created interface ( Fig. 1 ) to automatically track the anterior and posterior aortic walls over the cardiac cycle. Tissue Doppler allowed a precise estimation of the movement of each wall and the fine variation of the aortic diameter. MRSD was the maximum of the derivative of the diameter curve over time. To assess the feasibility of this new technique, 24 patients (10 BAV patients and 14 controls) were consecutively included in a reference center for BAV. The ascending aorta was evaluated at the sinus of Valsalva, the tubular aorta and the aortic arch. UF acquisitions and the dedicated interface allow to track the aortic diameter and to calculate the MRSD for the 10 BAV patients and 14 controls (mean age of 45.8 vs. 40.7 years, P = 0.464). As expected, a lower aortic strain was found at each aortic segment in case of BAV ( Table 1 ). MRSD values followed the same trend, as observed with MRI. As already demonstrated, the sinus of Valsalva has a high stiffness in case of BAV and we found a significant difference in MRSD with UF imaging (1.05 s-1 [0.73–1.19] vs. 1.51 s-1 [1.28–1.99], P = 0.023) ( Fig. 1 ). Aortic evaluation with UF by MRSD is feasible and can get access potentially to the evaluation of to the segmental ascending aortic remodeling associated to BAV using easy to use ultrasound based technique.