Orestis Vardoulis

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Total arterial compliance (C T) is a main determinant of cardiac afterload, left ventricular function and arterio-ventricular coupling. C T is physiologically more relevant than regional aortic stiffness. However, direct, in vivo, non-invasive, measurement of C T is not feasible. Several methods for indirect C T estimation require simultaneous recording of(More)
We introduce a novel variational framework for the regularized reconstruction of time-resolved volumetric flow fields. Our objective functional takes the physical characteristics of the underlying flow into account in both the spatial and the temporal domains. For an efficient minimization of the objective functional, we apply a proximal-splitting algorithm(More)
Associate Editor Dan Elson oversaw the review of this article. Gaddum et al., 2 recently published in Annals of Biomedical Engineering an interesting article seeking the optimal method for the estimation of arterial pulse transit time (TT) between two arterial sites. Accurate and precise TT estimation in vivo is a critical issue, because TT is one of the(More)
We propose a new variational framework for the problem of reconstructing flow fields from noisy measurements. The formalism is based on regularizers penalizing the singular values of the Jacobian of the field. Specifically, we rely on the nuclear norm. Our method is invariant with respect to fundamental transformations and can be efficiently solved. We(More)
BACKGROUND Left atrial (LA) dilatation is associated with a large variety of cardiac diseases. Current cardiovascular magnetic resonance (CMR) strategies to measure LA volumes are based on multi-breath-hold multi-slice acquisitions, which are time-consuming and susceptible to misregistration. AIM To develop a time-efficient single breath-hold 3D CMR(More)
PAR Aristotelis AGIANNIOTIS The best way to predict the future is to invent it. To my family for all their love and support… vii ACKNOWLEDGEMENTS I would like to acknowledge my co-workers, friends and family, who continuously supported me throughout my doctoral thesis. Foremost, my advisor, Prof. Nikos Stergiopulos, was instrumental in providing a research(More)
Aortic stiffness, assessed by carotid-to-femoral pulse wave velocity (PWV), often fails to predict cardiovascular (CV) risk and mortality in the very elderly. This may be due to the non-linear association between PWV and compliance or to blood pressure decrease in the frailest subjects. Total arterial compliance (C T) is the most relevant arterial property(More)
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