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Phase contrast Magnetic aortic

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https://www.readbyqxmd.com/read/29119728/a-framework-for-designing-patient-specific-bioprosthetic-heart-valves-using-immersogeometric-fluid-structure-interaction-analysis
#1
Fei Xu, Simone Morganti, Rana Zakerzadeh, David Kamensky, Ferdinando Auricchio, Alessandro Reali, Thomas J R Hughes, Michael S Sacks, Ming-Chen Hsu
Numerous studies have suggested that medical image derived computational mechanics models could be developed to reduce mortality and morbidity due to cardiovascular diseases by allowing for patient-specific surgical planning and customized medical device design. In this work, we present a novel framework for designing prosthetic heart valves using a parametric design platform and immersogeometric fluid-structure interaction (FSI) analysis. We parameterize the leaflet geometry using several key design parameters...
November 9, 2017: International Journal for Numerical Methods in Biomedical Engineering
https://www.readbyqxmd.com/read/29117252/preclinical-4d-flow-magnetic-resonance-phase-contrast-imaging-of-the-murine-aortic-arch
#2
Moritz Braig, Jochen Leupold, Marius Menza, Maximilian Russe, Cheng-Wen Ko, Juergen Hennig, Dominik von Elverfeldt
PURPOSE: Cardiovascular diseases remain the number one death cause worldwide. Preclinical 4D flow phase contrast magnetic resonance imaging can provide substantial insights in the analysis of aortic pathophysiologies in various animal models. These insights may allow a better understanding of pathophysiologies, therapy monitoring, and can possibly be translated to humans. This study provides a framework to acquire the velocity field within the aortic arch. It analyses important flow values at different locations within the aortic arch...
2017: PloS One
https://www.readbyqxmd.com/read/29037199/assessment-of-local-pulse-wave-velocity-distribution-in-mice-using-k-t-blast-pc-cmr-with-semi-automatic-area-segmentation
#3
Volker Herold, Stefan Herz, Patrick Winter, Fabian Tobias Gutjahr, Kristina Andelovic, Wolfgang Rudolf Bauer, Peter Michael Jakob
BACKGROUND: Local aortic pulse wave velocity (PWV) is a measure for vascular stiffness and has a predictive value for cardiovascular events. Ultra high field CMR scanners allow the quantification of local PWV in mice, however these systems are yet unable to monitor the distribution of local elasticities. METHODS: In the present study we provide a new accelerated method to quantify local aortic PWV in mice with phase-contrast cardiovascular magnetic resonance imaging (PC-CMR) at 17...
October 16, 2017: Journal of Cardiovascular Magnetic Resonance
https://www.readbyqxmd.com/read/28985849/treating-a-20-mm-hg-gradient-alleviates-myocardial-hypertrophy-in-experimental-aortic-coarctation
#4
David C Wendell, Ingeborg Friehs, Margaret M Samyn, Leanne M Harmann, John F LaDisa
BACKGROUND: Children with coarctation of the aorta (CoA) can have a hyperdynamic and remodeled left ventricle (LV) from increased afterload. Literature from an experimental model suggests the putative 20 mm Hg blood pressure gradient (BPG) treatment guideline frequently implemented in CoA studies may permit irreversible vascular changes. LV remodeling from pressure overload has been studied, but data are limited following correction and using a clinically representative BPG. MATERIALS AND METHODS: Rabbits underwent CoA at 10 weeks to induce a 20 mm Hg BPG using permanent or dissolvable suture thereby replicating untreated and corrected CoA, respectively...
October 2017: Journal of Surgical Research
https://www.readbyqxmd.com/read/28945128/comparison-of-left-and-right-ventricular-stroke-volume-of-dogs-calculated-on-the-basis-of-morphology-and-blood-flow-determined-by-use-of-cardiac-magnetic-resonance-imaging
#5
Matthias Dennler, Henning Richter, José Novo Matos, Marco Baron Toaldo, Ivo U Campagna, Tony M Glaus, Patrick R Kircher
OBJECTIVE To compare stroke volume (SV) calculated on the basis of cardiac morphology determined by MRI and results of phase-contrast angiography (PCA) of ventricular inflow and outflow in dogs. ANIMALS 10 healthy Beagles. PROCEDURES Cardiac MRI was performed twice on each Beagle. Cine gradient echo sequences of both ventricles in short-axis planes were used for morphological quantification of SVs by assessment of myocardial contours. From the long-axis plane, SVs in 4-chamber and left ventricular 2-chamber views were acquired at end diastole and end systole...
October 2017: American Journal of Veterinary Research
https://www.readbyqxmd.com/read/28932122/gadobutrol-in-india-a-comprehensive-review-of-safety-and-efficacy
#6
REVIEW
Jan Endrikat, Nicoletta Anzalone
Gadobutrol is a gadolinium (Gd)-based contrast agent for magnetic resonance imaging (MRI). In India, gadobutrol is approved for MRI of the central nervous system (CNS), liver, kidneys, breast and for MR angiography for patients 2 years and older. The standard dose for all age groups is 0.1 mmol/kg body weight. The safety profile has been demonstrated in 42 clinical phase 2 to 4 studies (>6800 patients), 7 observational studies, and by assessing pharmacovigilance data of 29 million applications. Furthermore, studies in children, adults, and elderly and in patients with impaired liver or kidney function did not show any increased adverse event rate...
2017: Magnetic Resonance Insights
https://www.readbyqxmd.com/read/28929446/new-imaging-tools-in-cardiovascular-medicine-computational-fluid-dynamics-and-4d-flow-mri
#7
Keiichi Itatani, Shohei Miyazaki, Tokoki Furusawa, Satoshi Numata, Sachiko Yamazaki, Kazuki Morimoto, Rina Makino, Hiroko Morichi, Teruyasu Nishino, Hitoshi Yaku
Blood flow imaging is a novel technology in cardiovascular medicine and surgery. Today, two types of blood flow imaging tools are available: measurement-based flow visualization including 4D flow MRI (or 3D cine phase-contrast magnetic resonance imaging), or echocardiography flow visualization software, and computer flow simulation modeling based on computational fluid dynamics (CFD). MRI and echocardiography flow visualization provide measured blood flow but have limitations in temporal and spatial resolution, whereas CFD flow calculates the flow according to assumptions instead of flow measurement, and it has sufficiently fine resolution up to the computer memory limit, and it enables even virtual surgery when combined with computer graphics...
November 2017: General Thoracic and Cardiovascular Surgery
https://www.readbyqxmd.com/read/28871348/characterization-of-complex-flow-patterns-in-the-ascending-aorta-in-patients-with-aortic-regurgitation-using-conventional-phase-contrast-velocity-mri
#8
Odd Bech-Hanssen, Frida Svensson, Christian L Polte, Åse A Johnsson, Sinsia A Gao, Kerstin M Lagerstrand
Ascending aorta (AA) flow displacement (FD) is a surrogate for increased wall shear stress. We prospectively studied the flow profile in the AA in patients with aortic regurgitation (AR), to identify predictors of FD and investigate whether magnetic resonance imaging (MRI) phase-contrast flow rate curves (PC-FRC) contain quantitative information related to FD. Forty patients with chronic moderate (n = 14) or severe (n = 26) AR (21 (53%) with bicuspid aortic valve) and 22 controls were investigated. FD was determined from phase-contrast velocity profiles and defined as the distance between the center of the lumen and the "center of velocity" of the peak systolic forward flow or the peak diastolic negative flow, normalized to the lumen radius...
September 4, 2017: International Journal of Cardiovascular Imaging
https://www.readbyqxmd.com/read/28822982/evaluation-of-aortic-regurgitation-with-cardiac-magnetic-resonance-imaging-a-systematic-review
#9
REVIEW
James C Lee, Kelley R Branch, Christian Hamilton-Craig, Eric V Krieger
This review summaries the utility, application and data supporting use of cardiac magnetic resonance imaging (CMR) to evaluate and quantitate aortic regurgitation. We systematically searched Medline and PubMed for original research articles published since 2000 that provided data on the quantitation of aortic regurgitation by CMR and identified 11 articles for review. Direct aortic measurements using phase contrast allow quantitation of volumetric flow across the aortic valve and are highly reproducible and accurate compared with echocardiography...
August 19, 2017: Heart: Official Journal of the British Cardiac Society
https://www.readbyqxmd.com/read/28744784/modeling-left-ventricular-blood-flow-using-smoothed-particle-hydrodynamics
#10
Andrés Caballero, Wenbin Mao, Liang Liang, John Oshinski, Charles Primiano, Raymond McKay, Susheel Kodali, Wei Sun
This study aims to investigate the capability of smoothed particle hydrodynamics (SPH), a fully Lagrangian mesh-free method, to simulate the bulk blood flow dynamics in two realistic left ventricular (LV) models. Three dimensional geometries and motion of the LV, proximal left atrium and aortic root are extracted from cardiac magnetic resonance imaging and multi-slice computed tomography imaging data. SPH simulation results are analyzed and compared with those obtained using a traditional finite volume-based numerical method, and to in vivo phase contrast magnetic resonance imaging and echocardiography data, in terms of the large-scale blood flow phenomena usually clinically measured...
July 25, 2017: Cardiovascular Engineering and Technology
https://www.readbyqxmd.com/read/28714282/variability-of-4d-flow-parameters-when-subjected-to-changes-in-mri-acquisition-parameters-using-a-realistic-thoracic-aortic-phantom
#11
Cristian Montalba, Jesus Urbina, Julio Sotelo, Marcelo E Andia, Cristian Tejos, Pablo Irarrazaval, Daniel E Hurtado, Israel Valverde, Sergio Uribe
PURPOSE: To assess the variability of peak flow, mean velocity, stroke volume, and wall shear stress measurements derived from 3D cine phase contrast (4D flow) sequences under different conditions of spatial and temporal resolutions. METHODS: We performed controlled experiments using a thoracic aortic phantom. The phantom was connected to a pulsatile flow pump, which simulated nine physiological conditions. For each condition, 4D flow data were acquired with different spatial and temporal resolutions...
July 16, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28694784/4d-flow-analysis-of-bav-related-fluid-dynamic-alterations-evidences-of-wall-shear-stress-alterations-in-absence-of-clinically-relevant-aortic-anatomical-remodeling
#12
Filippo Piatti, Francesco Sturla, Malenka M Bissell, Selene Pirola, Massimo Lombardi, Igor Nesteruk, Alessandro Della Corte, Alberto C L Redaelli, Emiliano Votta
Bicuspid aortic valve (BAV) is the most common congenital cardiac disease and is a foremost risk factor for aortopathies. Despite the genetic basis of BAV and of the associated aortopathies, BAV-related alterations in aortic fluid-dynamics, and particularly in wall shear stresses (WSSs), likely play a role in the progression of aortopathy, and may contribute to its pathogenesis. To test whether WSS may trigger aortopathy, in this study we used 4D Flow sequences of phase-contrast cardiac magnetic resonance imaging (CMR) to quantitatively compare the in vivo fluid dynamics in the thoracic aorta of two groups of subjects: (i) five prospectively enrolled young patients with normo-functional BAV and with no aortic dilation and (ii) ten age-matched healthy volunteers...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28673664/on-the-choice-of-outlet-boundary-conditions-for-patient-specific-analysis-of-aortic-flow-using-computational-fluid-dynamics
#13
S Pirola, Z Cheng, O A Jarral, D P O'Regan, J R Pepper, T Athanasiou, X Y Xu
Boundary conditions (BCs) are an essential part in computational fluid dynamics (CFD) simulations of blood flow in large arteries. Although several studies have investigated the influence of BCs on predicted flow patterns and hemodynamic wall parameters in various arterial models, there is a lack of comprehensive assessment of outlet BCs for patient-specific analysis of aortic flow. In this study, five different sets of outlet BCs were tested and compared using a subject-specific model of a normal aorta. Phase-contrast magnetic resonance imaging (PC-MRI) was performed on the same subject and velocity profiles extracted from the in vivo measurements were used as the inlet boundary condition...
June 20, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/28626199/oxygen-and-glucose-as-stimulation-agents-for-bold-functional-mr-imaging-of-rabbit-liver-a-feasibility-study
#14
Fang Yuan, Bin Song, Zixing Huang, Xijiao Liu, Chunchao Xia
PURPOSE: To assess the feasibility of using oxygen and glucose as stimulating agents in blood-oxygen-level-dependent (BOLD) Functional Magnetic Resonance Imaging (fMRI) of rabbit liver and analyze the impacts by blood flow. METHODS: Pure oxygen inhalation, intravenous injection and oral administration of glucose were given to 11 New Zealand white rabbits to compare the differences of liver T2*, aortic flow (AF), portal vein flow (PVF), aortic area (AA) and portal vein area (PVA) before and at 5 min, 10 min, 20 min, 30 min after administrations...
June 16, 2017: Magnetic Resonance in Medical Sciences: MRMS
https://www.readbyqxmd.com/read/28623496/association-between-flow-skewness-and-aortic-dilatation-in-patients-with-aortic-stenosis
#15
Hojin Ha, Hyun Jung Koo, June Goo Lee, Guk Bae Kim, Jihoon Kweon, Sang Joon Lee, Joon Won Kang, Tae Hwan Lim, Dae Hee Kim, Jong Min Song, Duk Hyun Kang, Jae Kwan Song, Young Hak Kim, Namkug Kim, Dong Hyun Yang
We investigated association between hemodynamic characteristics and aortic dilatation in patients with severe aortic stenosis (AS). Eighty patients with severe AS (mean age, 67.2 ± 12.5 years) who underwent multi-detector computed tomography and phase-contrast magnetic resonance imaging at the ascending aorta were retrospectively analyzed. Patients with an ascending aorta diameter >4 cm had a significantly higher forward flow rate at systole (28.5 ± 6.0 vs. 36.2 ± 8.6 L min, P < 0...
June 16, 2017: International Journal of Cardiovascular Imaging
https://www.readbyqxmd.com/read/28608325/pulsatile-flow-leads-to-intimal-flap-motion-and-flow-reversal-in-an-in-vitro-model-of-type-b-aortic-dissection
#16
Joav Birjiniuk, Lucas H Timmins, Mark Young, Bradley G Leshnower, John N Oshinski, David N Ku, Ravi K Veeraswamy
Understanding of the hemodynamics of Type B aortic dissection may improve outcomes by informing upon patient selection, device design, and deployment strategies. This project characterized changes to aortic hemodynamics as the result of dissection. We hypothesized that dissection would lead to elevated flow reversal and disrupted pulsatile flow patterns in the aorta that can be detected and quantified by non-invasive magnetic resonance imaging. Flexible, anatomic models of both normal aorta and dissected aorta, with a mobile intimal flap containing entry and exit tears, were perfused with a physiologic pulsatile waveform...
June 12, 2017: Cardiovascular Engineering and Technology
https://www.readbyqxmd.com/read/28453794/blood-flow-competition-after-aortic-valve-bypass-an-evaluation-using-computational-fluid-dynamics
#17
Koji Kawahito, Naoyuki Kimura, Kenji Komiya, Masanori Nakamura, Yoshio Misawa
OBJECTIVES: Aortic valve bypass (AVB) (apico-aortic conduit) remains an effective surgical alternative for patients in whom surgical aortic valve replacement or transcatheter aortic valve implantation is not feasible. However, specific complications include thrombus formation, possibly caused by stagnation arising from flow competition between the antegrade and retrograde flow, but this has not been fully investigated. The aim of this study was to analyse flow characteristics after AVB and to elucidate mechanisms of intra-aortic thrombus using computational fluid dynamics (CFD)...
May 1, 2017: Interactive Cardiovascular and Thoracic Surgery
https://www.readbyqxmd.com/read/28421174/utility-of-cardiovascular-magnetic-resonance-derived-wave-intensity-analysis-as-a-marker-of-ventricular-function-in-children-with-heart-failure-and-normal-ejection-fraction
#18
Hopewell N Ntsinjana, Robin Chung, Paolo Ciliberti, Vivek Muthurangu, Silvia Schievano, Jan Marek, Kim H Parker, Andrew M Taylor, Giovanni Biglino
OBJECTIVE: This study sought to explore the diagnostic insight of cardiovascular magnetic resonance (CMR)-derived wave intensity analysis to better study systolic dysfunction in young patients with chronic diastolic dysfunction and preserved ejection fraction (EF), comparing it against other echocardiographic and CMR parameters. BACKGROUND: Evaluating systolic and diastolic dysfunctions in children is challenging, and a gold standard method is currently lacking...
2017: Frontiers in Pediatrics
https://www.readbyqxmd.com/read/28346330/differentiation-of-impaired-from-preserved-hemodynamics-in-patients-with-fontan-circulation-using-real-time-phase-velocity-cardiovascular-magnetic-resonance
#19
Hermann Körperich, Katja Müller, Peter Barth, Jürgen Gieseke, Nikolaus Haas, Ingram Schulze-Neick, Wolfgang Burchert, Deniz Kececioglu, Kai T Laser
PURPOSE: Progressive impairment of hemodynamics in patients with Fontan circulation is common, multifactorial, and associated with decreased quality of life and increased morbidity. We sought to assess hemodynamic differences between patients with preserved (preserved Fontans) and those with impaired circulation (impaired Fontans) after pulmonary vasodilation using oxygen and under forced breathing conditions. MATERIALS AND METHODS: Real-time phase-contrast cardiovascular magnetic resonance was performed using non-ECG triggered echo-planar imaging (temporal resolution=24 to 28 ms) in the ascending aorta (AAo) and superior vena cava (SVC)/inferior vena cava (IVC) on room air, after 100% oxygen inhalation (4 L/min; 10 min) and on forced breathing in 29 Fontan patients (17...
May 2017: Journal of Thoracic Imaging
https://www.readbyqxmd.com/read/28342532/shear-scaling-based-approach-for-irreversible-energy-loss-estimation-in-stenotic-aortic-flow-an-in-vitro-study
#20
Utku Gülan, Christian Binter, Sebastian Kozerke, Markus Holzner
Today, the functional and risk assessment of stenosed arteries is mostly based on ultrasound Doppler blood flow velocity measurements or catheter pressure measurements, which rely on several assumptions. Alternatively, blood velocity including turbulent kinetic energy (TKE) may be measured using MRI. The aim of the present study is to validate a TKE-based approach that relies on the fact that turbulence production is dominated by the flow's shear to determine the total irreversible energy loss from MRI scans...
March 12, 2017: Journal of Biomechanics
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