Vascular Elastography: A Validation Study

Inflation and Bi-Axial Tensile Testing of Healthy Porcine Carotid Arteries

“…Similar measurements were reported for coronary arteries (Lally et al 2004) and healthy or aneurysmal aortic tissue (Duprey et al 2010;Holzapfel and Ogden 2006;Nicosia et al 2002;Okamoto et al 2002). Inflation testing characterizes the arterial tissue in more physiologic circumstances in vitro, that is, less destructive circumstances, and was previously employed on several types of arteries (Agianniotis et al 2012;Beattie et al 1998;Boekhoven et al 2014;Lopata et al 2014;Schulze-Bauer et al 2003;Vychytil et al 2010).…”

“…The direction and magnitude of the forces acting on the vessel sample can be matched for both methods. Lopata et al (2014) reported good agreement between the two methods when modeling the porcine aortic arterial wall as a neoHookean solid.…”

“…Vascular strain imaging and elastography are non-invasive techniques, allowing the assessment of strains and mechanical properties of the arterial wall from ultrasound, respectively (Baldewsing et al 2004;de Korte et al 1998;Fromageau et al 2008;Schmitt et al 2007). These techniques, however, have been validated experimentally on simple phantoms with known properties (Cinthio et al 2010;Larsson et al 2015;Ribbers et al 2007;Ryan and Foster 1997;Widman et al 2015) and on biological vascular tissue (Keyes et al 2013;Lopata et al 2014;. Studies that compare functional ultrasound measurements with measurements obtained with another experimental method are scarce.…”

“…From the radiofrequency (RF) data, local deformation fields are estimated and displayed as color overlays on the regular B-mode images, that is, strain imaging (Talhami et al 1994). The combination of inflation testing and ultrasound strain imaging has been used in healthy and atherosclerotic tissue (Boekhoven et al 2013;Ribbers et al 2007) and in other types of arteries, mostly in a quasi-static fashion (Brusseau et al 2001;de Korte et al 1998;Lopata et al 2014;Schaar et al 2003).…”

Supersonic Shear Wave Imaging to Assess Arterial Nonlinear Behavior and Anisotropy: Proof of Principle via Ex Vivo Testing of the Horse Aorta

“…This variation is smaller than in our experiments, which is not unexpected given that (i) shear waves were measured along the axis of the carotid and thus perpendicular to the main collagen fiber orientation and (ii) that in vivo stretch will be significantly lower than imposed in our experiment (circumferential stretch is typically in the order of 10% in young healthy subjects). Another study from Lopata et al [47] had a similar approach of validating ultrasound measurements with mechanical testing, but the paper studied a different ultrasound modality (vascular strain imaging) in 10 cylindrical porcine aortas during inflation experiments and afterwards performing biaxial tensile testing on the tissue samples. Their data indicated shear modulus in the order of 100-120 kPa, hence also lying within the range measured by other authors [33].…”