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4D Flow

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https://www.readbyqxmd.com/read/29218620/the-impact-of-injector-based-contrast-agent-administration-in-time-resolved-mra
#1
Johannes Budjan, Ulrike I Attenberger, Stefan O Schoenberg, Hubertus Pietsch, Gregor Jost
OBJECTIVES: Time-resolved contrast-enhanced MR angiography (4D-MRA), which allows the simultaneous visualization of the vasculature and blood-flow dynamics, is widely used in clinical routine. In this study, the impact of two different contrast agent injection methods on 4D-MRA was examined in a controlled, standardized setting in an animal model. METHODS: Six anesthetized Goettingen minipigs underwent two identical 4D-MRA examinations at 1.5 T in a single session...
December 7, 2017: European Radiology
https://www.readbyqxmd.com/read/29217489/fixed-volume-particle-trace-emission-for-the-analysis-of-left-atrial-blood-flow-using-4d-flow-mri
#2
Stephen Gaeta, Petter Dyverfeldt, Jonatan Eriksson, Carl-Johan Carlhäll, Tino Ebbers, Ann F Bolger
4D Flow MRI has been used to quantify normal and deranged left ventricular blood flow characteristics on the basis of functionally distinct flow components. However, the application of this technique to the atria is challenging due to the presence of continuous inflow. This continuous inflow necessitates plane-based emission of particle traces from the inlet veins, leading to particles that represents different amounts of blood, and related quantification errors. The purpose of this study was to develop a novel fixed-volume approach for particle tracing and employ this method to develop quantitative analysis of 4D blood flow characteristics in the left atrium...
December 4, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/29206322/4d-flow-mri-cardiac-function-and-t1-mapping-association-of-valve-mediated-changes-in-aortic-hemodynamics-with-left-ventricular-remodeling
#3
Julia Geiger, Amir A Rahsepar, Kenichiro Suwa, Alex Powell, Ahmadreza Ghasemiesfe, Alex J Barker, Jeremy D Collins, James C Carr, Michael Markl
BACKGROUND: Patients with bicuspid aortic valve (BAV) show altered hemodynamics in the ascending aorta that can be assessed by 4D flow MRI. PURPOSE: Comprehensive cardiac MRI was applied to test the hypothesis that BAV-mediated changes in aortic hemodynamics (wall shear stress [WSS] and velocity) are associated with parameters of left ventricular (LV) remodeling. STUDY TYPE: Retrospective data analysis. POPULATION: Forty-nine BAV patients (mean age = 50...
December 5, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/29205378/cardiac-gated-parametric-images-from-82-rb-pet-from-dynamic-frames-and-direct-4d-reconstruction
#4
Mary Germino, Richard E Carson
PURPOSE: Cardiac perfusion PET data can be reconstructed as a dynamic sequence and kinetic modeling performed to quantify myocardial blood flow, or reconstructed as static gated images to quantify function. Parametric images from dynamic PET are conventionally not gated, to allow use of all events with lower noise. An alternative method for dynamic PET is to incorporate the kinetic model into the reconstruction algorithm itself, bypassing the generation of a time series of emission images and directly producing parametric images...
December 5, 2017: Medical Physics
https://www.readbyqxmd.com/read/29190387/chronic-hyperandrogenemia-in-the-presence-and-absence-of-a-western-style-diet-impairs-ovarian-and-uterine-structure-function-in-young-adult-rhesus-monkeys
#5
Cecily V Bishop, Emily C Mishler, Diana L Takahashi, Taylor E Reiter, Kise R Bond, Cadence A True, Ov D Slayden, Richard L Stouffer
STUDY QUESTION: Does chronic hyperandrogenemia beginning at menarche, in the absence and presence of a western-style diet (WSD), alter ovarian and uterine structure-function in young adult rhesus monkeys? SUMMARY ANSWER: Phenotypic alterations in ovarian and uterine structure/function were induced by exogenous testosterone (T), and compounded in the presence of a WSD (T+WSD). WHAT IS KNOWN ALREADY: Hyperandrogenemia is a well-established component of PCOS and is observed in adolescent girls, indicating a potential pubertal onset of disease symptoms...
November 28, 2017: Human Reproduction
https://www.readbyqxmd.com/read/29179599/fetal-facial-expressions-in-small-for-gestational-age-and-growth-restricted-fetuses
#6
Nubuhiro Mori, Mohamed Ahmed Mostafa AboEllail, Chiaki Tenkumo, Kenji Kanenishi, Naoki Nishimoto, Toshiyuki Hata
OBJECTIVE: To evaluate the frequencies of fetal facial expressions among appropriate-for-gestational-age (AGA), small-for-gestational-age (SGA), and growth-restricted (FGR) fetuses. METHODS: Four-dimensional (4D) ultrasound was used to examine the facial expressions of 50 AGA, 25 SGA, and 6 FGR fetuses between 28 and 35 weeks of gestation. The frequencies of 7 facial expressions during 15-minute recordings were assessed. Comparison of facial expressions among the three groups was performed...
November 27, 2017: Journal of Maternal-fetal & Neonatal Medicine
https://www.readbyqxmd.com/read/29151545/-novel-perfusion-evaluation-method-using-phase-ratio-image-map-in-head-4d-ct
#7
Tomomi Ohmura, Yongbum Lee, Noriyuki Takahashi, Hideto Toyoshima
PURPOSE: CT perfusion (CTP) is a powerful tool for the assessment of cerebrovascular disease. However, CTP maps are significantly different depending on CTP software and algorithm, even when using identical image data. We developed a phase-ratio image map (PI map), which was a novel perfusion map, without using CTP software. The purpose of this study was to investigate the usefulness of the PI map by comparing it with a positron emission tomography (PET) image. METHODS: Twenty patients (16 men, 4 women; mean age: 61...
2017: Nihon Hoshasen Gijutsu Gakkai Zasshi
https://www.readbyqxmd.com/read/29128122/resilience-of-carbon-and-nitrogen-removal-due-to-aeration-interruption-in-aerated-treatment-wetlands
#8
Johannes Boog, Jaime Nivala, Thomas Aubron, Sibylle Mothes, Manfred van Afferden, Roland A Müller
Treatment wetlands have long been used for domestic and industrial wastewater treatment. In recent decades, treatment wetland technology has evolved and now includes intensified designs such as aerated treatment wetlands. Aerated treatment wetlands are particularly dependent on aeration, which requires reliable air pumps and, in most cases, electricity. Whether aerated treatment wetlands are resilient to disturbances such as an aeration interruption is currently not well known. In order to investigate this knowledge gap, we carried out a pilot-scale experiment on one aerated horizontal flow wetland and one aerated vertical flow wetland under warm (Twater>17°C) and cold (Twater<10°C) weather conditions...
November 8, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/29117252/preclinical-4d-flow-magnetic-resonance-phase-contrast-imaging-of-the-murine-aortic-arch
#9
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/29112643/assessment-of-fetal-congenital-heart-diseases-by-4-dimensional-ultrasound-using-spatiotemporal-image-correlation-pictorial-review
#10
Edward Araujo Júnior, Gabriele Tonni, Nathalie Jeanne Bravo-Valenzuela, Fabricio Da Silva Costa, Simon Meagher
The aim of this pictorial review is to describe the technical advances achieved through the application of 4-dimensional (4D) ultrasound using spatiotemporal image correlation (STIC) over conventional 2-dimensional ultrasound in the prenatal detection of congenital heart disease (CHD). Spatiotemporal image correlation is a volume imaging technique that simplifies fetal heart studies while providing more diagnostic information than is typically available from traditional 2-dimensional studies. Four-dimensional software allows the study of cardiac anatomy and function during a single cardiac cycle and has greatly contributed to diagnostic enhancement of CHD...
November 6, 2017: Ultrasound Quarterly
https://www.readbyqxmd.com/read/29098524/mechanical-dyssynchrony-alters-left-ventricular-flow-energetics-in-failing-hearts-with-lbbb-a-4d-flow-cmr-pilot-study
#11
Jakub Zajac, Jonatan Eriksson, Urban Alehagen, Tino Ebbers, Ann F Bolger, Carl-Johan Carlhäll
The impact of left bundle branch block (LBBB) related mechanical dyssynchrony on left ventricular (LV) diastolic function remains unclear. 4D flow cardiovascular magnetic resonance (CMR) has provided reliable markers of LV dysfunction: reduced volume and kinetic energy (KE) of the portion of LV inflow which passes directly to outflow (Direct Flow) has been demonstrated in failing hearts compared to normal hearts. We sought to investigate the impact of mechanical dyssynchrony on diastolic function by comparing 4D flow in myopathic LVs with and without LBBB...
November 2, 2017: International Journal of Cardiovascular Imaging
https://www.readbyqxmd.com/read/29091067/the-emerging-role-of-4d-synchrotron-x-ray-micro-tomography-for-climate-and-fossil-energy-studies-five-experiments-showing-the-present-capabilities-at%C3%A2-beamline-8-3-2-at-the-advanced-light-source
#12
Marco Voltolini, Abdelmoula Haboub, Shan Dou, Tae Hyuk Kwon, Alastair A MacDowell, Dilworth Y Parkinson, Jonathan Ajo-Franklin
Continuous improvements at X-ray imaging beamlines at synchrotron light sources have made dynamic synchrotron X-ray micro-computed tomography (SXR-µCT) experiments more routinely available to users, with a rapid increase in demand given its tremendous potential in very diverse areas. In this work a survey of five different four-dimensional SXR-µCT experiments is presented, examining five different parameters linked to the evolution of the investigated system, and tackling problems in different areas in earth sciences...
November 1, 2017: Journal of Synchrotron Radiation
https://www.readbyqxmd.com/read/29090998/pelvic-blood-flow-predicts-fibroid-volume-and-embolic-required-for-uterine-fibroid-embolization-a-pilot-study-with-4d-flow-mr-angiography
#13
Christopher D Malone, Arjun Banerjee, Marcus T Alley, Shreyas S Vasanawala, Anne C Roberts, Albert Hsiao
OBJECTIVE: We report here an initial experience using 4D flow MRI in pelvic imaging-specifically, in imaging uterine fibroids. We hypothesized that blood flow might correlate with fibroid volume and that quantifying blood flow might help to predict the amount of embolic required to achieve stasis at subsequent uterine fibroid embolization (UFE). MATERIALS AND METHODS: Thirty-three patients with uterine fibroids and seven control subjects underwent pelvic MRI with 4D flow imaging...
November 1, 2017: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/29060628/volumetric-analysis-of-respiratory-gated-whole-lung-and-liver-ct-data-with-motion-constrained-graph-cuts-segmentation
#14
Jung Won Cha, M Mehdi Farhangi, Neal Dunlap, Amir Amini
The conventional graph cuts technique has been widely used for image segmentation due to its ability to find the global minimum and its ease of implementation. However, it is an intensity-based technique and as a result is limited to segmentation applications where there is significant contrast between the object and the background. We modified the conventional graph cuts method by adding shape prior and motion information. Active shape models (ASM) with signed distance functions were used to capture the shape prior information, preventing unwanted surrounding tissue from becoming part of the segmented object...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/29060591/4d-real-time-phase-contrast-flow-mri-with-sparse-sampling
#15
Aiqi Sun, Bo Zhao, Rui Li, Chun Yuan
Conventional phase-contrast (PC) MRI relies on electrocardiogram (ECG)-synchronized cine acquisition and respiration control. It often results in relatively low data acquisition efficiency, and is unable to assess blood flow variabilities. Real-time imaging is a promising technique to overcome these limitations; however, it results in a challenging image reconstruction problem with highly-undersampled (k; t)-space data. This paper presents a novel model-based imaging method, which integrates low-rank modeling with parallel imaging, to enable 4D real-time PC MRI without ECG gating and respiration control...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/29053905/distinct-predictive-role-of-collateral-status-on-clinical-outcome-in-variant-stroke-subtypes-of-acute-large-arterial-occlusion
#16
Xuting Zhang, Meixia Zhang, Wenhong Ding, Shenqiang Yan, David S Liebeskind, Min Lou
BACKGROUND: Clinical trials have showed that robust collateral flow has a relationship with good clinical outcome, however, different stroke subtypes were lumped together. This study explored the relationship between baseline collaterals and the onset-to-imaging time (OIT), and the correlation between pre-treatment collateral status and clinical outcome among different subtypes. METHOD: We reviewed prospectively collected data from consecutive acute ischemic stroke (AIS) patients with acute middle cerebral artery occlusion who received reperfusion therapy...
October 20, 2017: European Journal of Neurology: the Official Journal of the European Federation of Neurological Societies
https://www.readbyqxmd.com/read/29053451/spatially-resolved-mr-compatible-doppler-ultrasound-proof-of-concept-for-triggering-of-diagnostic-quality-cardiovascular-mri-for-function-and-flow-quantification-at-3t
#17
Lindsey A Crowe, Gibran Manasseh, Aneta Chmielewski, Anne-Lise Hachulla, Daniel Speicher, Andreas Greiser, Hajo Muller, Thomas De Perrot, Jean-Paul Vallee, Rares Salomir
OBJECTIVES: We demonstrate the use of a Magnetic-Resonance (MR)-compatible ultrasound (US) imaging probe using spatially-resolved Doppler for diagnostic quality cardiovascular MR imaging as an initial step towards hybrid US/MR fetal imaging. METHODS: A newly developed technology for a dedicated MR-compatible phased array ultrasound-imaging probe acquired pulsed color Doppler carotid images, which were converted in near-real time to a trigger signal for cardiac cine and flow quantification MRI...
October 17, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/29037165/sequencing-flow-sorted-short-arm-of-haynaldia-villosa-chromosome-4v-provides-insights-into-its-molecular-structure-and-virtual-gene-order
#18
Jin Xiao, Keli Dai, Lian Fu, Jan Vrána, Marie Kubaláková, Wentao Wan, Haojie Sun, Jing Zhao, Chunyan Yu, Yufeng Wu, Michael Abrouk, Haiyan Wang, Jaroslav Doležel, Xiue Wang
BACKGROUND: Haynaldia villosa (H. villosa) has been recognized as a species potentially useful for wheat improvement. The availability of its genomic sequences will boost its research and application. RESULTS: In this work, the short arm of H. villosa chromosome 4V (4VS) was sorted by flow cytometry and sequenced using Illumina platform. About 170.6 Mb assembled sequences were obtained. Further analysis showed that repetitive elements accounted for about 64.6% of 4VS, while the coding fraction, which is corresponding to 1977 annotated genes, represented 1...
October 16, 2017: BMC Genomics
https://www.readbyqxmd.com/read/29019794/vessel-calibre-and-flow-splitting-relationships-at-the-internal-carotid-artery-terminal-bifurcation
#19
C Chnafa, P Bouillot, O Brina, B M A Delattre, M I Vargas, K O Lovblad, V M Pereira, D A Steinman
OBJECTIVE: Vessel lumen calibres and flow rates are thought to be related by mathematical power laws, reflecting the optimization of cardiac versus 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...
November 1, 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
#20
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
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