Purpose: Mechanical properties of the arteries are essential in assessing cardiovascular diseases. New imaging modalities that allow mapping strain, shear and elasticity distributions within the arterial wall are rapidly evolving. Very recently, our group introduced an iterative optical flow-based elastography method devoted to B-mode data. In this paper, the authors propose an adaptation of the optical flow method to investigate aortic remodeling following Kawasaki disease, an early childhood vasculitis. Namely, displacement and strain of the aortic wall are used to assess aortic stiffness in this human disease model. The authors also introduce a fully developed automatic method to support postprocessing data analysis.
Methods: The sequalae of Kawasaki disease on the ascending aorta were examined in children. The pathologic population (n = 4) was 15.00 ± 2.45 years old, while the healthy control population (n = 5) was 13.13 ± 0.18 years old. B-mode data were digitally recorded with commercially available cardiac echocardiography machines.
Results: Kawasaki disease had a very significant impact on the aortic stiffness. Indeed, pathologic subjects' aortic wall strain estimate was significantly lower compared to healthy controls (2.75% ± 0.56% versus 4.24% ± 0.65%, respectively; p < 0.001). Similarly, displacement of the aortic wall was also significantly lower compared to controls (p < 0.001).
Conclusions: The potential of the optical flow-based method to quantify aortic wall remodeling in a human disease model was demonstrated. The authors now intend to extend this investigation to a larger pathologic cohort with various degrees of vasculitis severity.