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Monica Sigovan

Bio: Monica Sigovan is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 2 citations.

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TL;DR: The measured velocities showed that blood flow keeps a parabolic sectional profile distal from CCA, ECA and ICA, while being quite disturbed in the carotid sinus with a significant decrease in magnitude making this site very prone to atherosclerosis.

4 citations


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TL;DR: In this paper, a wavy-walled arterial structure is simulated by applying a vorticity-stream function formulation approach. And the transformed dimensionless equations are further discretized using the finite difference method by developing the Peaceman-Rachford alternating direction implicit (P-R ADI) scheme.

4 citations

Journal ArticleDOI
TL;DR: In this article, the authors proposed a largeeddy simulation (LES) approach to carry out the hemodynamics and medication dispersion and deposition studies inside the descending aorta. And the analysis reveals that the flow separation causes a preferential deposition and build-up of low-density lipoproteins (LDL) on the arterial surface.
Abstract: The hemodynamics plays a key role in the transport processes, in the blood stream, and thus, on the accumulation and deposition of lipids and medication on the vessel’s wall. Therefore, understanding the hemodynamics of the arterial veins can advance the understanding of transport phenomena and prediction of deposition and buildup of the low-density lipoproteins (LDL) and particulate medication, on the arterial surfaces. Previous studies have showed that for pulsatile flow, laminar-turbulent flow transition may occur, particularly during intense exercises. Experimental and computational studies, of hemodynamics and transport phenomena, pose significant challenges due to the complex aorta’s geometry and arterial fluid dynamics. In the present study, we propose a large-eddy simulation (LES), computational approach, to carry out the hemodynamics and medication dispersion and deposition studies, inside the descending aorta. The analysis reveals that the flow separation causes a preferential deposition and build-up of low-density lipoproteins (LDL) on the arterial surface. Our study also shows that the flow boundary-layer separation is associated with an increase in deposition of the low-density lipoproteins. The analysis reveals the presence of Dean vortices, inside the aorta branches, which contribute to the reduction of the deposition and build-up of low-density lipoproteins on the arterial surfaces. The analysis of medication dispersion and deposition, inside the descending aorta, shows that the total medication deposition increases with the increase of particle size and density. Particles of fiber-like shape are more prone to deposition, and this is due to the fact that fiber-like particles align perfectly with the flow streamlines. Thus, the interaction of complex turbulent eddies with vessel’s wall causes medication deposition. The research shows that LES is a promising tool in the analysis of hemodynamics and medication transport and therefore, it may assist medical planning by providing surgeons with the elements of the blood flow such as, pressure, velocity, vorticity, wall-shear stresses, which cannot be measured in vivo and obtained with imaging techniques.

3 citations

Journal ArticleDOI
TL;DR: In this paper , simultaneous effects of tDCS on cerebral blood flow (CBF), venous blood oxygenation (Yv) and cerebral metabolic rate of oxygen (CMRO2) using simultaneous MRI in healthy adults to provide a reference frame for its neurobiological mechanisms.

1 citations

Journal ArticleDOI
TL;DR: The MRI‐based techniques that were used in the current study for measuring arterial flow in pediatric and adolescent patients demonstrated acceptable test‐retest reliability both at rest and immediately post‐exercise.
Abstract: Magnetic Resonance Imaging (MRI) is well‐suited for imaging peripheral blood flow due to its non‐invasive nature and excellent spatial resolution. Although MRI is routinely used in adults to assess physiological changes in chronic diseases, there are currently no MRI‐based data quantifying arterial flow in pediatric or adolescent populations during exercise. Therefore the current research sought to document femoral arterial blood flow at rest and following exercise in a pediatric‐adolescent population using phase contrast MRI, and to present test‐retest reliability data for this method. Ten healthy children and adolescents (4 male; mean age 14.8 ± 2.4 years) completed bloodwork and resting and exercise MRI. Baseline images consisted of PC‐MRI of the femoral artery at rest and following a 5 × 30 s of in‐magnet exercise. To evaluate test‐retest reliability, five participants returned for repeat testing. All participants successfully completed exercise testing in the MRI. Baseline flow demonstrated excellent reliability (ICC = 0.93, p = 0.006), and peak exercise and delta rest‐peak flow demonstrated good reliability (peak exercise ICC = 0.89, p = 0.002, delta rest‐peak ICC = 0.87, p = 0.003) between‐visits. All three flow measurements demonstrated excellent reliability when assessed with coefficients of variance (CV’s) (rest: CV = 6.2%; peak exercise: CV = 7.3%; delta rest‐peak: CV = 7.1%). The mean bias was small for femoral arterial flow. There was no significant mean bias between femoral artery flow visits 1 and 2 at peak exercise. There were no correlations between age or height and any of the flow measurements. There were no significant differences between male and female participants for any of the flow measurements. The current study determined that peripheral arterial blood flow in children and adolescents can be evaluated using non‐invasive phase contrast MRI. The MRI‐based techniques that were used in the current study for measuring arterial flow in pediatric and adolescent patients demonstrated acceptable test‐retest reliability both at rest and immediately post‐exercise.

1 citations