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Phase contrast Magnetic aortic

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https://www.readbyqxmd.com/read/28194732/late-post-avr-progression-of-bicuspid-aortopathy-link-to-hemodynamics
#1
Shiho Naito, Tatiana Gross, Kushtrim Disha, Yskert von Kodolitsch, Hermann Reichenspurner, Evaldas Girdauskas
BACKGROUND AND AIM OF THE STUDY: The ascending aortic dilatation may progress after aortic valve replacement (AVR) in bicuspid aortic valve (BAV) patients. Our aim was to evaluate rheological flow patterns and histological characteristics of the aneurysmal aorta in BAV patients at the time of reoperative aortic surgery. MATERIALS AND METHODS: 13 patients (mean age: 42 ± 9 years, 10 (77%) male) with significant progression of proximal aortopathy after isolated AVR surgery for BAV disease (i...
February 13, 2017: General Thoracic and Cardiovascular Surgery
https://www.readbyqxmd.com/read/28190607/patient-specific-assessment-of-hemodynamics-by-computational-fluid-dynamics-in-patients-with-bicuspid-aortopathy
#2
Naoyuki Kimura, Masanori Nakamura, Kenji Komiya, Satoshi Nishi, Atsushi Yamaguchi, Osamu Tanaka, Yoshio Misawa, Hideo Adachi, Koji Kawahito
OBJECTIVE: Hemodynamics related to eccentric blood flow may factor into the development of bicuspid aortic valve aortopathy. We investigated wall shear stress distribution by means of magnetic resonance imaging-based computational fluid dynamics in patients with a bicuspid aortic valve. METHODS: Included were 12 patients with a bicuspid aortic valve (aortic stenosis, n = 11; root enlargement, n = 1). Three patients with a normal tricuspid aortic valve (arch aneurysm, n = 1; descending aortic aneurysm, n = 2) were included for comparison...
January 11, 2017: Journal of Thoracic and Cardiovascular Surgery
https://www.readbyqxmd.com/read/28125720/false-lumen-flow-patterns-and-their-relation-with-morphological-and-biomechanical-characteristics-of-chronic-aortic-dissections-computational-model-compared-with-magnetic-resonance-imaging-measurements
#3
Paula A Rudenick, Patrick Segers, Victor Pineda, Hug Cuellar, David García-Dorado, Arturo Evangelista, Bart H Bijnens
Aortic wall stiffness, tear size and location and the presence of abdominal side branches arising from the false lumen (FL) are key properties potentially involved in FL enlargement in chronic aortic dissections (ADs). We hypothesize that temporal variations on FL flow patterns, as measured in a cross-section by phase-contrast magnetic resonance imaging (PC-MRI), could be used to infer integrated information on these features. In 33 patients with chronic descending AD, instantaneous flow profiles were quantified in the FL at diaphragm level by PC-MRI...
2017: PloS One
https://www.readbyqxmd.com/read/28119407/blood-flow-competition-after-aortic-valve-bypass-an-evaluation-using-computational-fluid-dynamics
#4
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)...
January 24, 2017: Interactive Cardiovascular and Thoracic Surgery
https://www.readbyqxmd.com/read/28115510/abnormal-wave-reflections-and-left-ventricular-hypertrophy-late-after-coarctation-of-the-aorta-repair
#5
Michael A Quail, Rebekah Short, Bejal Pandya, Jennifer A Steeden, Abbas Khushnood, Andrew M Taylor, Patrick Segers, Vivek Muthurangu
Patients with repaired coarctation of the aorta are thought to have increased afterload due to abnormalities in vessel structure and function. We have developed a novel cardiovascular magnetic resonance protocol that allows assessment of central hemodynamics, including central aortic systolic blood pressure, resistance, total arterial compliance, pulse wave velocity, and wave reflections. The main study aims were to (1) characterize group differences in central aortic systolic blood pressure and peripheral systolic blood pressure, (2) comprehensively evaluate afterload (including wave reflections) in the 2 groups, and (3) identify possible biomarkers among covariates associated with elevated left ventricular mass (LVM)...
March 2017: Hypertension
https://www.readbyqxmd.com/read/28088917/effects-of-heart-valve-prostheses-on-phase-contrast-flow-measurements-in-cardiovascular-magnetic-resonance-a-phantom-study
#6
Johanna Richau, Matthias A Dieringer, Julius Traber, Florian von Knobelsdorff-Brenkenhoff, Andreas Greiser, Carsten Schwenke, Jeanette Schulz-Menger
BACKGROUND: Cardiovascular Magnetic Resonance is often used to evaluate patients after heart valve replacement. This study systematically analyses the influence of heart valve prostheses on phase contrast measurements in a phantom trial. METHODS: Two biological and one mechanical aortic valve prostheses were integrated in a flow phantom. B0 maps and phase contrast measurements were acquired at a 1.5 T MR scanner using conventional gradient-echo sequences in predefined distances to the prostheses...
January 16, 2017: Journal of Cardiovascular Magnetic Resonance
https://www.readbyqxmd.com/read/28063459/cardiac-remodeling-following-reperfused-acute-myocardial-infarction-is-linked-to-the-concomitant-evolution-of-vascular-function-as-assessed-by-cardiovascular-magnetic-resonance
#7
Olivier Huttin, Damien Mandry, Romain Eschalier, Lin Zhang, Emilien Micard, Freddy Odille, Marine Beaumont, Renaud Fay, Jacques Felblinger, Edoardo Camenzind, Faïez Zannad, Nicolas Girerd, Pierre Y Marie
BACKGROUND: Left ventricular (LV) remodeling following acute myocardial infarction (MI) is difficult to predict at an individual level although a possible interfering role of vascular function has yet to be considered to date. This study aimed to determine the extent to which this LV remodeling is influenced by the concomitant evolution of vascular function and LV loading conditions, as assessed by phase-contrast Cardiovascular Magnetic Resonance (CMR) of the ascending aorta. METHODS: CMR was performed in 121 patients, 2-4 days after reperfusion of a first ST-segment elevation myocardial infarction and 6 months thereafter...
January 4, 2017: Journal of Cardiovascular Magnetic Resonance
https://www.readbyqxmd.com/read/27989036/ascending-aortic-stiffness-with-bicuspid-aortic-valve-is-variable-and-not-predicted-by-conventional-parameters-in-young-patients
#8
Nicholas S Burris, Petter Dyverfeldt, Michael D Hope
BACKGROUND: Bicuspid aortic valve (BAV)-related aortopathy is characterized by histological abnormalities that result in aortic wall stiffening and aortic dilation. The study aim was to determine the range of ascending aortic stiffness seen in a clinical cohort of patients with BAV, and to identify the association of aortic stiffness with standard clinical and imaging parameters. METHODS: Patients with BAV (n = 65) and normal subjects (n = 10) were studied using conventional phase-contrast magnetic resonance imaging through the ascending aorta...
May 2016: Journal of Heart Valve Disease
https://www.readbyqxmd.com/read/27942477/the-effect-of-reducing-spatial-resolution-by-in-plane-partial-volume-averaging-on-peak-velocity-measurements-in-phase-contrast-magnetic-resonance-angiography
#9
Jonathan Rodrigues, Kishore Minhas, Guido Pieles, Elisa McAlindon, Christopher Occleshaw, Nathan Manghat, Mark Hamilton
BACKGROUND: The aim of this study was to quantify the degree of the effect of in-plane partial volume averaging on recorded peak velocity in phase contrast magnetic resonance angiography (PCMRA). METHODS: Using cardiac optimized 1.5 Tesla MRI scanners (Siemens Symphony and Avanto), 145 flow measurements (14 anatomical locations; ventricular outlets, aortic valve (AorV), aorta (5 sites), pulmonary arteries (3 sites), pulmonary veins, superior and inferior vena cava)- in 37 subjects (consisting of healthy volunteers, congenital and acquired heart disease patients) were analyzed by Siemens Argus default voxel averaging technique (where peak velocity = mean of highest velocity voxel and four neighbouring voxels) and by single voxel technique (1...
October 2016: Quantitative Imaging in Medicine and Surgery
https://www.readbyqxmd.com/read/27847162/patient-specific-computational-fluid-dynamics-assessment-of-aortic-hemodynamics-in-a-spectrum-of-aortic-valve-pathologies
#10
Pouya Youssefi, Alberto Gomez, Taigang He, Lisa Anderson, Nick Bunce, Rajan Sharma, C Alberto Figueroa, Marjan Jahangiri
OBJECTIVES: The complexity of aortic disease is not fully exposed by aortic dimensions alone, and morbidity or mortality can occur before intervention thresholds are met. Patient-specific computational fluid dynamics (CFD) were used to assess the effect of different aortic valve morphologies on velocity profiles, flow patterns, helicity, wall shear stress (WSS), and oscillatory shear index (OSI) in the thoracic aorta. METHODS: A total of 45 subjects were divided into 5 groups: volunteers, aortic regurgitation-tricuspid aortic valve (AR-TAV), aortic stenosis-tricuspid aortic valve (AS-TAV), aortic stenosis-bicuspid aortic valve right-left cusp fusion (BAV[RL]), and aortic stenosis-right-non cusp fusion (AS-BAV[RN])...
January 2017: Journal of Thoracic and Cardiovascular Surgery
https://www.readbyqxmd.com/read/27599727/flow-measurement-at-the-aortic-root-impact-of-location-of-through-plane-phase-contrast-velocity-mapping
#11
Litten Bertelsen, Jesper Hastrup Svendsen, Lars Køber, Ketil Haugan, Søren Højberg, Carsten Thomsen, Niels Vejlstrup
BACKGROUND: Cardiovascular magnetic resonance (CMR) is considered the gold standard of cardiac volumetric measurements. Flow in the aortic root is often measured at the sinotubular junction, even though placing the slice just above valve level may be more precise. It is unknown how much flow measurements vary at different levels in the aortic root and which level corresponds best to left ventricle volumetry. METHODS: All patients were older than 70 years presenting with at least one of the following diagnoses: diabetes, hypertension, prior stroke and/or heart failure...
September 7, 2016: Journal of Cardiovascular Magnetic Resonance
https://www.readbyqxmd.com/read/27561388/the-influence-of-the-aortic-valve-angle-on-the-hemodynamic-features-of-the-thoracic-aorta
#12
Hojin Ha, Guk Bae Kim, Jihoon Kweon, Sang Joon Lee, Young-Hak Kim, Namkug Kim, Dong Hyun Yang
Since the first observation of a helical flow pattern in aortic blood flow, the existence of helical blood flow has been found to be associated with various pathological conditions such as bicuspid aortic valve, aortic stenosis, and aortic dilatation. However, an understanding of the development of helical blood flow and its clinical implications are still lacking. In our present study, we hypothesized that the direction and angle of aortic inflow can influence helical flow patterns and related hemodynamic features in the thoracic aorta...
2016: Scientific Reports
https://www.readbyqxmd.com/read/27543698/normal-age-related-changes-in-left-ventricular-function-role-of-afterload-and-subendocardial-dysfunction
#13
Jehill D Parikh, Kieren G Hollingsworth, Dorothy Wallace, Andrew M Blamire, Guy A MacGowan
BACKGROUND: In normal ageing, both vascular and ventricular properties change, and how these affect left ventricular function is not clear. METHODS: 96 subjects (ages 20-79) without cardiovascular disease underwent cardiac magnetic resonance (MR) imaging for measurement of global function, diastolic function (E/A ratio), MR tagging for measurement of torsion to shortening ratio (TSR, ratio of epicardial torsion to endocardial circumferential shortening, with increase in TSR suggesting subendocardial dysfunction relative to the subepicardium), and phase contrast MR imaging measurement of central aortic pulse wave velocity (PWV)...
November 15, 2016: International Journal of Cardiology
https://www.readbyqxmd.com/read/27508739/-op-5b-05-characterisation-of-longitudinal-changes-in-vascular-structure-and-function-over-a-4-year-follow-up-period-as-assessed-by-mri
#14
M Cecelja, T Hussain, M Silva Vieira, A Phinikaridou, G Greil, T Spector, P Chowienczyk
OBJECTIVE: Vascular aging is characterised by structural changes: wall thickening and change in lumen diameter, together with functional changes in aortic stiffness. We investigated the longitudinal structural and functional changes that occur in the aortic wall over a 4 year follow-up period. DESIGN AND METHOD: Magnetic resonance imaging (MRI) was performed in 38 asymptomatic women aged between 53-73 years at baseline and 4 years later over from the aortic arch to aortic bifurcation...
September 2016: Journal of Hypertension
https://www.readbyqxmd.com/read/27491900/cardiovascular-magnetic-resonance-to-evaluate-aortic-regurgitation-after-transcatheter-aortic-valve-replacement
#15
Henrique B Ribeiro, Stefan Orwat, Salim S Hayek, Éric Larose, Vasilis Babaliaros, Abdellaziz Dahou, Florent Le Ven, Sergio Pasian, Rishi Puri, Omar Abdul-Jawad Altisent, Francisco Campelo-Parada, Marie-Annick Clavel, Philippe Pibarot, Stamatios Lerakis, Helmut Baumgartner, Josep Rodés-Cabau
BACKGROUND: Residual aortic regurgitation (AR) following transcatheter aortic valve replacement (TAVR) is associated with greater mortality; yet, determining AR severity post-TAVR using Doppler echocardiography remains challenging. Cardiovascular magnetic resonance (CMR) is purported as a more accurate means of quantifying AR; however, no data exist regarding the prognostic value of AR as assessed by CMR post-TAVR. OBJECTIVES: This study sought to evaluate the effect of AR assessed with CMR on clinical outcomes post-TAVR...
August 9, 2016: Journal of the American College of Cardiology
https://www.readbyqxmd.com/read/27423836/time-resolved-3-dimensional-magnetic-resonance-phase-contrast-imaging-4d-flow-mri-analysis-of-hemodynamics-in-valve-sparing-aortic-root-repair-with-an-anatomically-shaped-sinus-prosthesis
#16
Thekla H Oechtering, Carl F Hons, Malte Sieren, Peter Hunold, Anja Hennemuth, Markus Huellebrand, Johann Drexl, Michael Scharfschwerdt, Doreen Richardt, Hans-Hinrich Sievers, Jörg Barkhausen, Alex Frydrychowicz
OBJECTIVE: The anatomically shaped sinus prosthesis (Uni-Graft W SINUS; Braun, Melsungen, Germany) used in valve-sparing aortic root replacement promises physiological hemodynamics believed to grant physiologic valve function. Using time-resolved 3-dimensional magnetic resonance phase contrast imaging (4D Flow MRI), we analyzed sinus vortex formation and transvalvular pressure gradients in patients with sinus prosthesis compared with age-matched and young healthy volunteers. METHODS: Twelve patients with sinus prosthesis (55 ± 15 years), 12 age-matched and 6 young healthy volunteers (55 ± 6 years, 25 ± 3 years, respectively) were examined at 3T with a 4D flow magnetic resonance imaging sequence...
August 2016: Journal of Thoracic and Cardiovascular Surgery
https://www.readbyqxmd.com/read/27387199/required-temporal-resolution-for-accurate-thoracic-aortic-pulse-wave-velocity-measurements-by-phase-contrast-magnetic-resonance-imaging-and-comparison-with-clinical-standard-applanation-tonometry
#17
Karolina Dorniak, Einar Heiberg, Marcin Hellmann, Dorota Rawicz-Zegrzda, Maria Wesierska, Rafal Galaska, Agnieszka Sabisz, Edyta Szurowska, Maria Dudziak, Erik Hedström
BACKGROUND: Pulse wave velocity (PWV) is a biomarker for arterial stiffness, clinically assessed by applanation tonometry (AT). Increased use of phase-contrast cardiac magnetic resonance (CMR) imaging allows for PWV assessment with minor routine protocol additions. The aims were to investigate the acquired temporal resolution needed for accurate and precise measurements of CMR-PWV, and develop a tool for CMR-PWV measurements. METHODS: Computer phantoms were generated for PWV = 2-20 m/s based on human CMR-PWV data...
2016: BMC Cardiovascular Disorders
https://www.readbyqxmd.com/read/27379534/oscillometric-analysis-compared-with-cardiac-magnetic-resonance-for-the-assessment-of-aortic-pulse-wave-velocity-in-patients-with-myocardial-infarction
#18
Hans-Josef Feistritzer, Gert Klug, Sebastian J Reinstadler, Martin Reindl, Agnes Mayr, Michael Schocke, Bernhard Metzler
OBJECTIVES: Measurement of aortic pulse wave velocity (PWV) is the gold standard for assessment of aortic stiffness. In patients with ST-segment elevation myocardial infarction (STEMI), high aortic PWV has deleterious effects on the myocardium. In the present study, we compared a novel oscillometric device with cardiac magnetic resonance (CMR) imaging for the assessment of aortic PWV in STEMI patients. METHODS: We measured aortic PWV in 60 reperfused STEMI patients using two different methods...
September 2016: Journal of Hypertension
https://www.readbyqxmd.com/read/27353852/association-of-aortic-stiffness-with-left-ventricular-remodeling-and-reduced-left-ventricular-function-measured-by-magnetic-resonance-imaging-the-multi-ethnic-study-of-atherosclerosis
#19
Yoshiaki Ohyama, Bharath Ambale-Venkatesh, Chikara Noda, Atul R Chugh, Gisela Teixido-Tura, Jang-Young Kim, Sirisha Donekal, Kihei Yoneyama, Ola Gjesdal, Alban Redheuil, Chia-Ying Liu, Tetsuya Nakamura, Colin O Wu, W Gregory Hundley, David A Bluemke, Joao A C Lima
BACKGROUND: This study sought to assess cross-sectional associations of aortic stiffness assessed by magnetic resonance imaging with left ventricular (LV) remodeling and myocardial deformation in the Multi-Ethnic Study of Atherosclerosis (MESA). METHODS AND RESULTS: Aortic arch pulse wave velocity (PWV) was measured with phase contrast cine magnetic resonance imaging. LV circumferential strain (Ecc), torsion, and early diastolic strain rate were determined by tagged magnetic resonance imaging...
July 2016: Circulation. Cardiovascular Imaging
https://www.readbyqxmd.com/read/27222592/systolic-flow-displacement-using-3d-magnetic-resonance-imaging-in-an-experimental-model-of-ascending-aorta-aneurysm-impact-of-rheological-factors
#20
Ali Ayaon-Albarran, Rodrigo Fernandez-Jimenez, Jacobo Silva-Guisasola, Jaume Agüero, Javier Sanchez-Gonzalez, Carlos Galan-Arriola, Fernando Reguillo-Lacruz, Luis C Maroto Castellanos, Borja Ibanez
OBJECTIVES: The impact of systolic flow displacement on the development and progression of ascending aorta dilatation in aortic valve disease is a matter of controversy. Our objective was to study the association between rheological stimuli and development of aortic dilatation in a large animal model of supravalvular aortic stenosis and eccentric flow. METHODS: Twenty-four pigs weighing 10-14 kg were randomly allocated (ratio 2:1) to either restrictive ascending aortic banding or sham operation...
October 2016: European Journal of Cardio-thoracic Surgery
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