A Four-Criterion Selection Procedure for Atherosclerotic Plaque Elasticity Reconstruction Based on in Vivo Coronary Intravascular Ultrasound Radial Strain Sequences

Abstract

Plaque elasticity (i.e. modulogram) and morphology are good predictors of plaque vulnerability. Recently, our group developed an intravascular ultrasound (IVUS) elasticity reconstruction method which was successfully implemented in vitro using vessel phantoms. In vivo IVUS modulography, however, remains a major challenge as the motion of the heart prevents accurate strain field estimation. We therefore designed a technique to extract accurate strain fields and modulograms from recorded IVUS sequences. We identified a set of four criteria based on tissue overlapping, RF-correlation coefficient between two successive frames, performance of the elasticity reconstruction method to recover the measured radial strain, and reproducibility of the computed modulograms over the cardiac cycle. This 4-CSP was successfully tested on IVUS sequences obtained in twelve patients referred for a directional coronary atherectomy intervention. This study demonstrates the potential of the IVUS modulography technique based on the proposed 4-CSP to detect vulnerable plaques in vivo.

Image-based modeling for better understanding and assessment of atherosclerotic plaque progression and vulnerability: Data, modeling, validation, uncertainty and predictions

“…Quantifying tissue material properties based on in vivo data is challenging. Le Floc'h et al (2012) and Baldewsing et al (2008) have conducted research to reconstruct in vivo vulnerable plaque (VP) elasticity. A four-criterion selection procedure was proposed for plaque elasticity reconstruction based on in vivo coronary IVUS radial strain sequences and was tested on data obtained from 12 patients (Le Floc'h et al, 2012).…”

“…Le Floc'h et al (2012) and Baldewsing et al (2008) have conducted research to reconstruct in vivo vulnerable plaque (VP) elasticity. A four-criterion selection procedure was proposed for plaque elasticity reconstruction based on in vivo coronary IVUS radial strain sequences and was tested on data obtained from 12 patients (Le Floc'h et al, 2012). As it is known that plaque has heterogeneous morphology and local material property is needed to have accurate stress/strain calculations, Baldewsing et al introduced an inverse method for imaging the local plaque elasticity.…”

“…The mechanisms causing plaque rupture and subsequent clinical events are not fully understood (Fuster, 1998; Fuster et al, 1990; Naghavi et al, 2003a, 2003b). Considerable progress has been made in recent years in medical imaging (Yuan et al, 2001a, 2001b; Underhill, et al, 2010), histopathological analysis (Stary et al, 1992, 1994, 1995; Virmani et al, 2000, 2006), biomechanical plaque material properties (Finet et al, 2004; Le Floc'h et al, 2012; Baldewsing et al, 2008), mechanical stress risk factors (Richardson et al, 1989; Arroyo and Lee, 1999; Ohayon et al, 2011; Loree et al, 1992). and computational models (Tang, 2006; Friedman et al, 2010) for better understanding of plaque progression, rupture and to develop possible better patient screening and plaque assessment schemes.…”

Biomechanics of Atherosclerotic Coronary Plaque: Site, Stability and In Vivo Elasticity Modeling

“…As below, this four-criterion selection procedure (4-CSP) was successfully tested on IVUS sequences obtained in twelve patients referred for a directional coronary atherectomy intervention. 45 As such, this study demonstrates the potential of the IVUS modulography technique based on the proposed 4-CSP to detect vulnerable plaques in vivo .…”

“…The details of both the improved S–SM palpography technique and the 4-CSP approach to solving the inverse problem of deciphering moduli from serial IVUS images are described in Deleaval et al 19 and Le Floc’h et al , 45 respectively. As regards the 4-CSP method, for each patient’s atherosclerotic lesion, approximately 30 displacement maps were reconstructed based on the IVUS sequence recorded during one second.…”