Four-dimensional Ultrasound for Characterization of In Vivo Murine Aortic Valve Dynamics. (9th April 2021)

• Record Type: Journal Article
• Authors: Gramling, Daniel P.; Damen, Frederick W.; Thatcher, Kaitlyn; Feng, Xinzeng; Sacks, Michael S.; Breuer, Christopher K.; Lincoln, Joy; Goergen, Craig J.
• Is Part Of: Structural heart. Volume 5(2021)Supplement 1
• Page Start: 27
• Page End: 27
• Publication Date: 2021-04-09
• Subjects: Heart -- Diseases -- Periodicals; Congenital heart disease -- Periodicals; Cardiovascular system -- Diseases -- Periodicals; Cardiovascular Diseases; Cardiovascular system -- Diseases; Congenital heart disease; Heart -- Diseases; Periodicals; 616.12
• DOI: 10.1080/24748706.2021.1901532
• Languages: English
• ISSNs: 2474-8706

Abstract

Abstract : Objective : Aortic valve (AoV) disease affects up to 5% of Americans over 65 years age. While AoV disease is frequently diagnosed using 3D transesophageal echocardiography, these same methods are not available for small animals, hindering the ability to track disease progression. A recently developed small animal imaging technique, four-dimensional ultrasound (4DUS), has opened the possibility of direct AoV visualization in mice. Methods : Data Acquisition : 4DUS imaging (Vevo 3100; FUJIFILM VisualSonics) was performed on the AoVs of 16 C57BL/6J mice, consisting of ten wild-type (n=5 each, male and female, 3 months old), and three osteogenesis imperfecta mice with three littermate controls (12 months old). Data Analysis : AoV data was loaded into a custom MATLAB toolbox for analysis. Data was oriented orthogonal to the aortic annulus, stabilized against intra-thoracic motion, and boundary-tracked using discrete points along both the AoV wall and the leaflet free edge. Results : This method allows for volumetric visualization of the valve across the cardiac cycle, shown here in open (Figure 1B ) and closed (1C ) states. Analysis-derived surfaces composing the three AoV leaflets are extracted and provide 3D visualizations of leaflet dynamics, as shown in the open (Figure 1D ) and closed (1E ) states with calculated displacement from end-diastole overlaid. Peak average displacements of each leaflet in the mouse displayed here were RCC: 0.38mm (yellow star), LCC: 0.35mm, and NCC: 0.31mm. Conclusions : We demonstrate the ability to reliably capture gated, volumetric in vivo data of the murine AoV, which were previously only reported through 1D and 2D measures. The technique detailed here allows for robust assessment of leaflet dynamics in 3D, thus providing a foundation for longitudinal characterization of murine models of aortic valve disease.