An intravascular coronary plaque elasticity reconstruction method using limited depth penetration ultrasound signals

Abstract

Vulnerable atherosclerotic plaque (VP) rupture is the leading cause of acute coronary syndrome, myocardial infarction and stroke in the Western world (Go et al. 2013). Although past studies have identified fibrous cap thickness (Capthick) as the primary predictor of coronary plaque rupture (Virmani et al. 2006), biomechanical studies have recognized peak cap stress (PCS) as an additional key predictor of plaque disruption (Ohayon et al. 2008). Quantification of PCS amplitude requires not only an accurate description of plaque morphology but also a precise knowledge of the mechanical properties of plaque components. An early and accurate determination of these properties remains an essential step to implement preventive therapeutic strategies. A previous approach (named iMOD for imaging modulography) has been conducted by our group to reconstruct the Young’s modulus map (i.e. modulogram) from intravascular ultrasound (IVUS) strain-elastogram (Le Floc’h et al. 2009). However, one major limitation of such a method is the need to accurately estimate the strain field in the entire lesion, which may be often difficult when using HD-IVUS techniques with limited depth penetration signals (Kobayashi et al. 2014). Therefore, an extended iMOD approach (E-iMOD), based on the continuum mechanics theory prescribing the strain field in the limited atherosclerotic endoluminal region, was designed and successfully applied to coronary lesions of patients imaged in vivo with IVUS.