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4D Flow

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https://www.readbyqxmd.com/read/29019794/vessel-calibre-and-flow-splitting-relationships-at-the-internal-carotid-artery-terminal-bifurcation
#1
Christophe Chnafa, Pierre Bouillot, Olivier Brina, Benedicte M A Delattre, Maria I Vargas, Karl-Olaf Lovblad, Vitor M Pereira, David A Steinman
Vessel lumen calibres and flow rates are thought to be related by mathematical power laws, reflecting the optimization of cardiac vs. metabolic work. While these laws have been confirmed indirectly via measurement of branch calibres, there is little data confirming power law relationships of flow distribution to branch calibres at individual bifurcations. Approach: Flow rates and diameters of parent and daughter vessels of the internal carotid artery terminal bifurcation were determined, via robust and automated methods, from 4D phase-contrast magnetic resonance imaging and 3D rotational angiography of 31 patients...
October 11, 2017: Physiological Measurement
https://www.readbyqxmd.com/read/28980342/3d-axial-and-circumferential-wall-shear-stress-from-4d-flow-mri-data-using-a-finite-element-method-and-a-laplacian-approach
#2
Julio Sotelo, Lydia Dux-Santoy, Andrea Guala, José Rodríguez-Palomares, Arturo Evangelista, Carlos Sing-Long, Jesús Urbina, Joaquín Mura, Daniel E Hurtado, Sergio Uribe
PURPOSE: To decompose the 3D wall shear stress (WSS) vector field into its axial (WSSA ) and circumferential (WSSC ) components using a Laplacian finite element approach. METHODS: We validated our method with in silico experiments involving different geometries and a modified Poiseuille flow. We computed 3D maps of the WSS, WSSA , and WSSC using 4D flow MRI data obtained from 10 volunteers and 10 patients with bicuspid aortic valve (BAV). We compared our method with the centerline method...
October 4, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28965146/biventricular-vortex-ring-formation-corresponds-to-regions-of-highest-intraventricular-viscous-energy-loss-in-a-fontan-patient-analysis-by-4d-flow-mri
#3
Vivian P Kamphuis, Arno A W Roest, Jos J M Westenberg, Mohammed S M Elbaz
No abstract text is available yet for this article.
September 30, 2017: International Journal of Cardiovascular Imaging
https://www.readbyqxmd.com/read/28964556/primetime-for-clinical-and-research-application-of-intra-cardiac-4d-flow-cmr
#4
EDITORIAL
Pier Giorgio Masci
No abstract text is available yet for this article.
September 28, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28964555/clinical-applications-of-intra-cardiac-four-dimensional-flow-cardiovascular-magnetic-resonance-a-systematic-review
#5
Saul Crandon, Mohammed S M Elbaz, Jos J M Westenberg, Rob J van der Geest, Sven Plein, Pankaj Garg
BACKGROUND: Four-dimensional flow cardiovascular magnetic resonance (4D flow CMR) is an emerging non-invasive imaging technology used to visualise and quantify intra-cardiac blood flow. The aim of this systematic review is to assess the literature on the current clinical applications of intra-cardiac 4D flow CMR. METHODS: A systematic review was conducted to evaluate the literature on the intra-cardiac clinical applications of 4D flow CMR. Structured searches were carried out on Medline, EMBASE and the Cochrane Library in October 2016...
September 28, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28961100/an-mri-compatible-hydrodynamic-simulator-of-cerebrospinal-fluid-motion-in-the-cervical-spine
#6
Suraj Thyagaraj, Soroush H Pahlavian, Lucas R Sass, Francis Loth, Morteza Vatani, Jao-Won Choi, R Shane Tubbs, Daniel Giese, Jan-Robert Kroger, Alexander C Bunck, Bryn A Martin
GOAL: Develop and test an MRI-compatible hydrodynamic simulator of cerebrospinal fluid (CSF) motion in the cervical spinal subarachnoid space. Four anatomically realistic subject-specific models were created based on a 22-year-old healthy volunteer and a five-year-old patient diagnosed with Chiari I malformation. METHODS: The in vitro models were based on manual segmentation of high-resolution T2-weighted MRI of the cervical spine. Anatomically realistic dorsal and ventral spinal cord nerve rootlets (NR) were added...
September 26, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28955513/visualization-of-soft-tissue-venous-malformations-of-head-and-neck-with-4d-flow-magnetic-resonance-imaging
#7
Ji Ye Lee, Dae Chul Suh
Evaluation of hemodynamics in venous malformation (VM) in the head and neck area is done by direct puncture venography before alcohol sclerotherapy, but it is difficult due to a variable degree of filling in from the artery and filling out into the draining vein. We present our preliminary experience of 4D MRI to evaluate VM hemodynamics. Four patients with venous malformation in the maxillofacial area underwent both 4D MRI and direct puncture venography before alcohol sclerotherapy. To find out appropriate velocity encoding (VENC) for VM, we applied 5-50 cm/sec VENC...
September 2017: Neurointervention
https://www.readbyqxmd.com/read/28952510/4d-flow-assessment-of-vorticity-in-right-ventricular-diastolic-dysfunction
#8
James R Browning, Jean R Hertzberg, Joyce D Schroeder, Brett E Fenster
Diastolic dysfunction, a leading cause of heart failure in the US, is a complex pathology which manifests morphological and hemodynamic changes in the heart and circulatory system. Recent advances in time-resolved phase-contrast cardiac magnetic resonance imaging (4D Flow) have allowed for characterization of blood flow in the right ventricle (RV) and right atrium (RA), including calculation of vorticity and qualitative visual assessment of coherent flow patterns. We hypothesize that right ventricular diastolic dysfunction (RVDD) is associated with changes in vorticity and right heart blood flow...
April 5, 2017: Bioengineering
https://www.readbyqxmd.com/read/28929446/new-imaging-tools-in-cardiovascular-medicine-computational-fluid-dynamics-and-4d-flow-mri
#9
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...
September 19, 2017: General Thoracic and Cardiovascular Surgery
https://www.readbyqxmd.com/read/28925047/voxel-by-voxel-4d-flow-mri-based-assessment-of-regional-reverse-flow-in-the-aorta
#10
Xin Shen, Susanne Schnell, Alex J Barker, Kenichiro Suwa, Lingzi Tashakkor, Kelly Jarvis, James C Carr, Jeremy D Collins, Shyam Prabhakaran, Michael Markl
BACKGROUND: Complex and reverse flow in the aorta has been implicated in aneurysm development and stroke via retrograde embolization. PURPOSE: To evaluate global and regional differences between standard 2D plane-based and volumetric voxel-based quantification of regional forward/reverse flow, and reverse flow fraction (RFF) in the aorta. STUDY TYPE: Retrospective. SUBJECTS: In all, 35 subjects: 10 healthy controls (age: 57 ± 7 years, nine male), nine patients without aortic valve regurgitation (AR) (age: 63 ± 10 years, seven male), six patients with mild AR (age: 66 ± 6 years, five male), and 10 with moderate or severe AR (age: 60 ± 16 years, eight male)...
September 18, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28921052/in-vitro-evaluation-of-flow-patterns-and-turbulent-kinetic-energy-in-trans-catheter-aortic-valve-prostheses
#11
Daniel Giese, Kilian Weiss, Bettina Baeßler, Navid Madershahian, Yeong-Hoon Choi, David Maintz, Alexander C Bunck
OBJECTIVES: The objective of the current work was to evaluate flow and turbulent kinetic energy in different transcatheter aortic valve implants using highly undersampled time-resolved multi-point 3-directional phase-contrast measurements (4D Flow MRI) in an in vitro setup. MATERIALS AND METHODS: A pulsatile flow setup was used with a compliant tubing mimicking a stiff left ventricular outflow tract and ascending aorta. Five different implants were measured using a highly undersampled multi-point 4D Flow MRI sequence...
September 18, 2017: Magma
https://www.readbyqxmd.com/read/28913838/simultaneous-acquisition-of-perfusion-image-and-dynamic-mr-angiography-using-time-encoded-pseudo-continuous-asl
#12
Yuriko Suzuki, Michael Helle, Peter Koken, Marc Van Cauteren, Matthias J P van Osch
PURPOSE: Both dynamic magnetic resonance angiography (4D-MRA) and perfusion imaging can be acquired by using arterial spin labeling (ASL). While 4D-MRA highlights large vessel pathology, such as stenosis or collateral blood flow patterns, perfusion imaging provides information on the microvascular status. Therefore, a complete picture of the cerebral hemodynamic condition could be obtained by combining the two techniques. Here, we propose a novel technique for simultaneous acquisition of 4D-MRA and perfusion imaging using time-encoded pseudo-continuous arterial spin labeling...
September 14, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28905268/fluid-and-biomechanical-analysis-of-ascending-thoracic-aorta-aneurysm-with-concomitant-aortic-insufficiency
#13
F Condemi, S Campisi, M Viallon, T Troalen, G Xuexin, A J Barker, M Markl, P Croisille, O Trabelsi, C Cavinato, A Duprey, S Avril
We present a comprehensive and original framework for the biomechanical analysis of patients affected by ascending thoracic aorta aneurysm and aortic insufficiency. Our aim is to obtain crucial indications about the role played by deranged hemodynamics on the ATAAs risk of rupture. Computational fluid dynamics analysis was performed using patient-specific geometries and boundary conditions derived from 4D MRI. Blood flow helicity and wall shear stress descriptors were assessed. A bulge inflation test was carried out in vitro on the 4 ATAAs after surgical repair...
September 13, 2017: Annals of Biomedical Engineering
https://www.readbyqxmd.com/read/28884401/4d-flow-image-quality-with-blood-pool-contrast-a-comparison-of-gadofosveset-trisodium-and-ferumoxytol
#14
Kanae Mukai, Nicholas S Burris, Vaikom S Mahadevan, Elyse D Foster, Karen G Ordovas, Michael D Hope
To evaluate the effect of MRI blood pool contrast agent on 4D flow image quality and ventricular volume measurements. Adult patients referred for clinical cardiac MRI (n = 22) were imaged with 4D flow. Patients with renal failure (n = 10) received ferumoxytol, and the remainder (n = 12) received gadofosveset trisodium. Image quality was assessed with (1) signal-to-noise ratio (SNR); (2) contrast-to-noise ratio (CNR); and (3) 5-point Likert scale based on endocardial border definition (1 = none; 2 = partial but unable to visualize; 3 = able to roughly estimate; 4 = visible for most of the cardiac cycle; 5 = excellent definition)...
September 8, 2017: International Journal of Cardiovascular Imaging
https://www.readbyqxmd.com/read/28877718/aortic-atheroma-as-a-source-of-stroke-assessment-of-embolization-risk-using-3d-cmr-in-stroke-patients-and-controls
#15
Thomas Wehrum, Iulius Dragonu, Christoph Strecker, Florian Schuchardt, Anja Hennemuth, Johann Drexl, Thomas Reinhard, Daniel Böhringer, Werner Vach, Jürgen Hennig, Andreas Harloff
BACKGROUND: It was our purpose to identify vulnerable plaques in the thoracic aorta using 3D multi-contrast CMR and estimate the risk of cerebral embolization using 4D flow CMR in cryptogenic stroke patients and controls. METHODS: One hundred patients (40 with cryptogenic stroke, 60 ophthalmologic controls matched for age, sex and presence of hypertension) underwent a novel 3D multi-contrast (T1w, T2w, PDw) CMR protocol at 3 Tesla for plaque detection and characterization within the thoracic aorta, which was combined with 4D flow CMR for mapping potential embolization pathways...
September 6, 2017: Journal of Cardiovascular Magnetic Resonance
https://www.readbyqxmd.com/read/28858856/impact-of-fitting-algorithms-on-errors-of-parameter-estimates-in-dynamic-contrast-enhanced-mri
#16
Charlotte Debus, Ralf Floca, Dominik Nörenberg, Amir Abdollahi, Michael Ingrisch
Parameter estimation in dynamic contrast-enhanced MRI (DCE MRI) is usually performed by non-linear least square (NLLS) fitting of a pharmacokinetic model to a measured concentration-time curve. The two-compartment exchange model (2CXM) describes the compartments "plasma" and "interstitial volume" and their exchange in terms of plasma flow and capillary permeability. The model function can be defined by either a system of two coupled differential equations or a closed-form analytical solution. The aim of this study was to compare these two representations in terms of accuracy, robustness and computation speed, depending on parameter combination and temporal sampling...
August 31, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28833523/modeling-of-coarctation-of-aorta-in-human-fetuses-using-3d-4d-fetal-echocardiography-and-computational-fluid-dynamics
#17
Zhuo Chen, Yue Zhou, Jingying Wang, Xiaowei Liu, Shuping Ge, Yihua He
OBJECTIVES: We sought to develop a hemodynamic model of aortic and ductal arches using computational fluid dynamics (CFD) and 3D/4D spatio-temporal image correlation (STIC) fetal echocardiography and to investigate the hemodynamics of coarctation of aorta (CoA) in human fetuses using this approach. METHODS: We obtained 3D/4D STIC fetal echocardiographic images of the aortic and ductal arches (DA) in five normal fetuses. Based on these images, we simulated the hemodynamics in the two arches using CFD...
August 22, 2017: Echocardiography
https://www.readbyqxmd.com/read/28827099/4d-cardiac-imaging-at-clinical-3-0t-provides-accurate-assessment-of-murine-myocardial-function-and-viability
#18
Lindsey A Crowe, Fabrizio Montecucco, Federico Carbone, Iris Friedli, Anne-Lise Hachulla, Vincent Braunersreuther, François Mach, Jean-Paul Vallée
OBJECTIVES: We validate a 4D strategy tailored for 3T clinical systems to simultaneously quantify function and infarct size in wild type mice after ischemia/reperfusion, with improved spatial and temporal resolution by comparison to previous published protocols using clinical field MRI systems. METHODS: C57BL/6J mice underwent 60min ischemia/reperfusion (n=14) or were controls without surgery (n=6). Twenty-four hours after surgery mice were imaged with gadolinium injection and sacrificed for post-mortem MRI and histology with serum also taken for Troponin I levels...
August 5, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28791908/synthesis-and-biological-evaluation-of-novel-7-hydroxy-4-phenylchromen-2-one-linked-to-triazole-moieties-as-potent-cytotoxic-agents
#19
Chuan-Feng Liu, Qing-Kun Shen, Jia-Jun Li, Yu-Shun Tian, Zheshan Quan
A new series of novel 7-hydroxy-4-phenylchromen-2-one (1a)-linked 1,2,4-triazoles were synthesised using a click chemistry approach. All derivatives were subjected to 3-(4,5-dimethylthiazol-yl)-diphenyl tetrazolium bromide (MTT) cytotoxicity screening against a panel of six different human cancer cell lines (AGS, MGC-803, HCT-116, A-549, HepG2, and HeLa) to assess their cytotoxic potential. Among the tested molecules, some of the analogues showed better cytotoxic activity than that shown by the 7-hydroxy-4-phenylchromen-2-one (1a)...
December 2017: Journal of Enzyme Inhibition and Medicinal Chemistry
https://www.readbyqxmd.com/read/28783626/fast-and-fully-automatic-left-ventricular-segmentation-and-tracking-in-echocardiography-using-shape-based-b-spline-explicit-active-surfaces
#20
Joao Pedrosa, Sandro Queiros, Olivier Bernard, Jan Engvall, Thor Edvardsen, Eike Nagel, Jan Dhooge
Cardiac volume/function assessment remains a critical step in daily cardiology and 3D ultrasound plays an increasingly important role. Fully automatic left ventricular segmentation is, however, a challenging task due to the artifacts and low contrast-to-noise ratio of ultrasound imaging. In the present work, a fast and fully automatic framework for full cycle endocardial left ventricle segmentation is proposed. This approach couples the advantages of the B-spline explicit active surfaces framework, a purely image information approach, to those of statistical shape models to give prior information about the expected shape for an accurate segmentation...
August 2, 2017: IEEE Transactions on Medical Imaging
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