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

Study aims 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. 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. 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 (100%) compared
with the baseline model for all subjects.
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.tudy aims t