Study of reproducibility of human arterial plaque reconstruction and its effects on stress analysis based on multispectral in vivo magnetic resonance imaging

Abstract

Purpose:To quantify the uncertainties of carotid plaque morphology reconstruction based on patient-specific multispectral in vivo magnetic resonance imaging (MRI) and their impacts on the plaque stress analysis. Materials and Methods:In this study, three independent investigators were invited to reconstruct the carotid bifurcation with plaque based on MR images from two subjects to study the geometry reconstruction reproducibility. Finite element stress analyses were performed on the carotid bifurcations, as well as the models with artificially modified plaque geometries to mimic the image segmentation uncertainties, to study the impacts of the uncertainties to the stress prediction.Results: Plaque reconstruction reproducibility was generally high in the study. The uncertainties among interobservers are around one or the subpixel level. It also shows that the predicted stress is relatively less sensitive to the arterial wall segmentation uncertainties, and more affected by the accuracy of lipid region definition. For a model with lipid core region artificially increased by adding one pixel on the lipid region boundary, it will significantly increase the maximum Von Mises Stress in fibrous cap (Ͼ100%) compared with the baseline model for all subjects. Conclusion:The current in vivo MRI in the carotid plaque could provide useful and reliable information for plaque morphology. The accuracy of stress analysis based on plaque geometry is subject to MRI quality. The improved resolution/ quality in plaque imaging with newly developed MRI protocols would generate more realistic stress predictions.

Study of carotid arterial plaque stress for symptomatic and asymptomatic patients

“…The fibrous cap area influenced by the one-pixel thickness assignment for the 8 symptomatic patients was around 14.1% of the total fibrous cap area, while for the 2 asymptomatic patients the average area was 10.2%. Therefore FCT and FPS values could be overestimated and underestimated, respectively, for symptomatic patients (Gao et al, 2009a). The result that FPS was significantly higher in symptomatic group than asymptomatic group might not be influenced by the fibrous cap segmentation uncertainties in the current study.…”

“…Recent developments in high-resolution multi-spectral MRI have allowed plaque components to be visualized in-vivo (Hatsukami et al, 2000;Cai et al, 2002;Yuan et al, 2002), providing more realistic plaque geometries for stress analysis (Touze et al, 2007;Gao et al, 2009a). Based on 2D in-vivo MRI, Li et al (2007) found that stress in asymptomatic patients was lower than that in symptomatic patients.…”

The Influence of Inaccuracies in Carotid MRI Segmentation on Atherosclerotic Plaque Stress Computations

“…The current clinically achievable resolution of in vivo MRI is a limiting factor in measuring submillimeter features such as thin FCs, which are especially present in vulnerable plaques [11,15,19,23,24]. This raises concern, because the sensitivity of biomechanical FEA plaque models to FC thickness is very high [13,14,25,26].…”

“…Carotid magnetic resonance imaging (]VIRI) is the method of choice to obtain the piaque composition and geometry in vivo noninvasively through image segmentation [17,18]. This makes ]VIRI-based FEA a promising methodology to better assess patient-specific carotid plaque vulnerability noninvasively, and numerous studies have utilized MRI-based FEA for carotid plaque [11,15,[19][20][21][22].…”

Utility of Magnetic Resonance Imaging-Based Finite Element Analysis for the Biomechanical Stress Analysis of Hemorrhagic and Non-Hemorrhagic Carotid Plaques

“…The reproducibility of the biomechanical stress simulations has been determined previously by our group. 25 …”