Dimitris Mitsouras

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Heart disease is the number one killer in the United States, and finding indicators of the disease at an early stage is critical for treatment and prevention. In this paper we evaluate visualization techniques that enable the diagnosis of coronary artery disease. A key physical quantity of medical interest is endothelial shear stress (ESS). Low ESS has been(More)
Fast spin echo (FSE) trains elicited by nonselective "hard" refocusing radio frequency (RF) pulses have been proposed as a means to enable application of FSE methods for high-resolution 3D magnetic resonance imaging (MRI). Hard-pulse FSE (HPFSE) trains offer short (3-4 ms) echo spacings, but are unfortunately limited to imaging the entire sample within the(More)
a r t i c l e i n f o a b s t r a c t We present a computational method for commodity hardware-based clinical cardiovascular diagnosis based on accurate simulation of cardiovascular blood flow. Our approach leverages the flexibility of the Lattice Boltzmann method to implementation on high-performance, commodity hardware, such as Graph-ical Processing(More)
A 3D inner-volume fast spin echo (3D IV-FSE) sequence was developed for ECG-gated, black-blood, T1- and T2-weighted vessel wall imaging of peripheral vein bypass grafts (PVBG). The sequence utilizes nonselective refocusing excitations to minimize echo spacings and a highly selective IV excitation scheme to minimize the need for oversampling of z-encode(More)
This method is an extension of the phase correlation method for image registration to multi-dimensional data sets. Through use of a high-order singular value decomposition , phase correlation can be used to identify transla-tional displacements independently along each dimension with subpixel resolution. The validity of this approach is demonstrated using(More)
Lower extremity peripheral vein bypass grafts (LE-PVBG) imaged with high-resolution black blood three-dimensional (3D) inner-volume (IV) fast spin echo (FSE) MRI at 1.5 Tesla possess a two-layer appearance in T1W images while only the inner layer appears visible in the corresponding T2W images. This study quantifies this difference in six patients imaged 6(More)
Spatially selective excitations can increase the acquisition efficiency of MRI by encoding the signal prior to acquisition using encoding bases other than the Fourier basis. However, spatially selective excitations require relatively long RF pulses which may limit their usefulness. Spiral trajectories through k-space can be used to minimize excitation time(More)
Selective RF excitation is employed in magnetic resonance imaging (MRI) to achieve a variety of effects, such as slice selection. More elaborate transverse magnetization patterns can be realized via tailored RF excitation pulses, useful for example to image any specific region geometry within the field of view, or, to acquire non-Fourier encoded samples of(More)
This paper describes a general theoretical framework that combines non-Fourier (NF) spatially-encoded MRI with multichannel acquisition parallel MRI. The two spatial-encoding mechanisms are physically and analytically separable, which allows NF encoding to be expressed as complementary to the inherent encoding imposed by RF receiver coil sensitivities.(More)
A recently developed method for exact density compensation of non uniformly arranged samples relies on the analytically known cross-correlations of Fourier basis functions corresponding to the traced k-space trajectory. This method produces a linear system whose solution represents compensated samples that normalize the contribution of each independent(More)