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4D Flow

Per Martin Arvidsson, Johannes Töger, Marcus Carlsson, Katarina Steding-Ehrenborg, Gianni Pedrizzetti, Einar Heiberg, Hakan Arheden
Intracardiac blood flow is driven by hemodynamic forces that are exchanged between the blood and myocardium. Previous studies have been limited to 2D measurements or investigated only LV forces. Right ventricular forces and their mechanistic contribution to asymmetric redirection of flow in the RV have not been measured. We therefore aimed to quantify three-dimensional hemodynamic forces in both ventricles in a cohort of healthy subjects, using magnetic resonance imaging 4D flow measurements. 25 controls,14 elite endurance athletes, and two patients with left ventricular dyssynchrony were included...
October 21, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Benjamin Bahr, Sebastian Steinhaus
Building on recent advances in defining Wilsonian renormalization group (RG) flows, and the notion of scales in particular, for background-independent theories, we present a first investigation of the renormalization of the 4D spin-foam path integral for quantum gravity, both analytically and numerically. Focusing on a specific truncation of the model using a hypercubic lattice, we compute the RG flow and find strong indications for a phase transition, as well as an interesting interplay between the different observed phases and the (broken) diffeomorphism symmetry of the model...
September 30, 2016: Physical Review Letters
Hongchao Jiang, Ceshi Chen, Qiangming Sun, Jing Wu, Lijuan Qiu, Change Gao, Weiqing Liu, Jun Yang, Nie Jun, Jian Dong
BACKGROUND: Semaphorin 4D (Sema4D) is highly expressed in certain types of tumors and functions in the regulation of tumor angiogenesis and growth. However, it is still not clear regarding the roles of Sema4D in breast cancer. This study was designed to explore the effects of Sema4D on proliferation, cell cycle progression, apoptosis, invasion, migration, tumor growth, and angiogenesis in breast cancer. MATERIALS AND METHODS: The expression level of Sema4D was investigated in MCF10A, 184A1, HCC1937, MDA-MB-468, MDA-MB-231, Hs578T, BT474, MCF-7, and T47D breast cancer cell lines by Western blotting analysis...
2016: OncoTargets and Therapy
Ursula Reiter, Gert Reiter, Martin Manninger, Gabriel Adelsmayr, Julia Schipke, Alessio Alogna, Alexandra Rajces, Aurelien F Stalder, Andreas Greiser, Christian Mühlfeld, Daniel Scherr, Heiner Post, Burkert Pieske, Michael Fuchsjäger
BACKGROUND: The hypertensive deoxy-corticosterone acetate (DOCA)-salt-treated pig (hereafter, DOCA pig) was recently introduced as large animal model for early-stage heart failure with preserved ejection fraction (HFpEF). The aim of the present study was to evaluate cardiovascular magnetic resonance (CMR) of DOCA pigs and weight-matched control pigs to characterize ventricular, atrial and myocardial structure and function of this phenotype model. METHODS: Five anesthetized DOCA and seven control pigs underwent 3 T CMR at rest and during dobutamine stress...
September 30, 2016: Journal of Cardiovascular Magnetic Resonance
Michael Rose, Ozair Rahman, Susanne Schnell, Joshua Robinson, Cynthia Rigsby
No abstract text is available yet for this article.
September 27, 2016: European Heart Journal Cardiovascular Imaging
Lillian M Lai, Joseph Y Cheng, Marcus T Alley, Tao Zhang, Michael Lustig, Shreyas S Vasanawala
PURPOSE: To assess the feasibility of ferumoxytol-enhanced anesthesia-free cardiac MRI in neonates and young infants for complex congenital heart disease (CHD). MATERIALS AND METHODS: With Institutional Review Board approval, 21 consecutive neonates and young infants (1 day to 11 weeks old; median age of 3 days) who underwent a rapid two-sequence (MR angiography [MRA] and four-dimensional [4D] flow) MRI protocol with intravenous ferumoxytol without sedation (n = 17) or light sedation (n = 4) at 3 Tesla (T) (except one case at 1...
September 28, 2016: Journal of Magnetic Resonance Imaging: JMRI
Saeed Mirsadraee, John H Reid, Martin Connell, William MacNee, Nikhil Hirani, John T Murchison, Edwin J van Beek
OBJECTIVE: Resolution and long-term functional effects of pulmonary emboli are unpredictable. This study was carried out to assess persisting vascular bed perfusion abnormalities and resolution of arterial thrombus in patients with recent pulmonary embolism (PE). METHODS AND MATERIALS: 26 Patients were prospectively evaluated by dynamic (4D) contrast enhanced CT perfusion dynamic pulmonary CT perfusion. Intermittent volume imaging was performed every 1.5-1.7s during breath-hold and perfusion values were calculated by maximum-slope technique...
October 2016: European Journal of Radiology
Raluca G Chelu, Kevin W Wanambiro, Albert Hsiao, Laurens E Swart, Teun Voogd, Allard T van den Hoven, Matthijs van Kranenburg, Adriaan Coenen, Sara Boccalini, Piotr A Wielopolski, Mika W Vogel, Gabriel P Krestin, Shreyas S Vasanawala, Ricardo P J Budde, Jolien W Roos-Hesselink, Koen Nieman
OBJECTIVES: In this study, we evaluated a cloud-based platform for cardiac magnetic resonance (CMR) four-dimensional (4D) flow imaging, with fully integrated correction for eddy currents, Maxwell phase effects, and gradient field non-linearity, to quantify forward flow, regurgitation, and peak systolic velocity over the pulmonary artery. METHODS: We prospectively recruited 52 adult patients during one-year period from July 2014. The 4D flow and planar (2D) phase-contrast (PC) were acquired during same scanning session, but 4D flow was scanned after injection of a gadolinium-based contrast agent...
October 2016: European Journal of Radiology
Hadi Wiputra, Chang Quan Lai, Guat Ling Lim, Joel Jia Wei Heng, Lan Guo, Hwa Liang Leo, Sanah Merchant Soomar, Arijit Biswas, Citra Nurfarah Zaini Mattar, Choon Hwai Yap
0.6-1.9% of US children were born with congenital heart malformations. Clinical and animal studies suggests that abnormal blood flow forces might play a role in causing these malformation, highlighting the importance of understanding the fetal cardiovascular fluid mechanics. We performed Computational Fluid Dynamics simulations of the right ventricles, based on 4D ultrasound scans of three 20 weeks old normal human foetuses, to characterize their flow and energy dynamics. Peak intraventricular pressure gradients were found to be 0...
September 23, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Kelly Jarvis, Marleen Vonder, Alex J Barker, Susanne Schnell, Michael Rose, James Carr, Joshua D Robinson, Michael Markl, Cynthia K Rigsby
BACKGROUND: Peak velocity measurements are used to evaluate the significance of stenosis in patients with transposition of the great arteries after the arterial switch operation (TGA after ASO). 4D flow cardiovascular magnetic resonance (CMR) provides 3-directional velocity encoding and full volumetric coverage of the great arteries and may thus improve the hemodynamic evaluation in these patients. The aim of this study was to compare peak velocities measured by 4D flow CMR with 2D phase contrast (PC) CMR and the gold standard Doppler echocardiography (echo) in patients with TGA after ASO...
2016: Journal of Cardiovascular Magnetic Resonance
Chintamaneni Raja Lakshmi, Doppalapudi Radhika, Mpv Prabhat, Sujana Mulk Bhavana, Nallamilli Sai Madhavi
Background. The aim of this study was to assess the relationship between genetic taste sensitivity, dietary preferences and salivary flow rate in 6‒14-year-old children for identification of individuals at higher risk of developing dental caries. Methods. A total of 500 children 6‒14 years of age, of both genders, who reported to the Department of Oral Medicine and Radiology, were included. Propylthiouracil (PROP) sensitivity test was carried out and the subjects whose perception was bitter were grouped as tasters, whereas those who were unable to perceive any taste were grouped as non-tasters...
2016: Journal of Dental Research, Dental Clinics, Dental Prospects
Fraser M Callaghan, Clare Arnott, Gemma A Figtree, Shelby Kutty, David S Celermajer, Stuart M Grieve
PURPOSE: To quantitatively characterize the central role of vortex formation on the flow patterns and energy transfer within the right atrium (RA). MATERIALS AND METHODS: 4D-flow magnetic resonance imaging (MRI) data with multiple encoding velocities was acquired in 12 healthy subjects at 3T. Particles entering the RA were classified according to the origin of entry. Vortex membership was numerically derived by assessing the location of pathline center of curvature relative to the vortex core, defined by Q-criteria...
September 14, 2016: Journal of Magnetic Resonance Imaging: JMRI
Michael Markl, Daniel C Lee, Nicholas Furiasse, Maria Carr, Charles Foucar, Jason Ng, James Carr, Jeffrey J Goldberger
BACKGROUND: Atrial 4D flow magnetic resonance imaging was used for the characterization of left atrial (LA) and left atrial appendage (LAA) flow dynamics in patients with atrial fibrillation (AF). METHODS AND RESULTS: 4D flow magnetic resonance imaging measured in vivo 3D blood flow velocities in 60 AF patients and 15 controls. Anatomic maps of LA and LAA stasis and velocity were calculated to quantify atrial peak velocity, mean velocity, and stasis (velocities <0...
September 2016: Circulation. Cardiovascular Imaging
Arunark Kolipaka, Venkata Sita Priyanka Illapani, Prateek Kalra, Julio Garcia, Xiaokui Mo, Michael Markl, Richard D White
PURPOSE: Aortic wall shear stress (WSSFlow ) alters endothelial function, which in-turn changes aortic wall stiffness leading to remodeling in different disease states. Therefore, the aims of this study are to determine normal physiologic correlations between: (1) Magnetic Resonance Elastography (MRE)-derived aortic wall stiffness (WSMRE ) and WSSFlow ; (2) WSMRE and mean velocity; (3) WSMRE and pulse wave velocity (PWV);( 4) WSMRE and mean peak flow; and (5) WSMRE , WSSFlow and age using MRE and 4D-flow MRI in the abdominal aorta in healthy human subjects...
September 7, 2016: Journal of Magnetic Resonance Imaging: JMRI
Thomas Henzler, Nils Vogler, Bettina Lange, Franz Dally, Mathias Meyer, Stefan O Schoenberg, Maliha Sadick
OBJECTIVES: To prospectively evaluate the diagnostic value and radiation dose of time-resolved CT-Angiography (4D-CTA) in pediatric patients with venous malformations using 3rd generation dual-source CT (DSCT) at 70 kVp tube voltage. METHODS: Between November 2014 and August 2015, seven children (2 male, 5 female; median age, 9 years; range 3-12 years) with suspected peripheral, non-cerebral, venous malformations were included in this feasibility study and underwent US, MRI and 4D-CTA...
2016: European Journal of Radiology Open
Julio Garcia, Alex J Barker, Jeremy D Collins, James C Carr, Michael Markl
PURPOSE: Absolute local normalized helicity (LNH) can differentiate flow alterations in the aorta between healthy controls and bicuspid aortic valve (BAV) patients. METHODS: A total of 65 controls and 50 subjects with BAV underwent in vivo four-dimensional (4D) flow MRI. Data analysis included the three-dimensional (3D) segmentation of the thoracic aorta (ascending aorta, aortic arch, and descending aorta) and calculation of absolute LNH. The mean velocity in the entire aorta was used to identify peak systole, systolic deceleration, and middiastole...
August 19, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Emil Svalbring, Alexandru Fredriksson, Jonatan Eriksson, Petter Dyverfeldt, Tino Ebbers, Ann F Bolger, Jan Engvall, Carl-Johan Carlhäll
AIMS: 4D flow magnetic resonance imaging (MRI) allows quantitative assessment of left ventricular (LV) function according to characteristics of the dynamic flow in the chamber. Marked abnormalities in flow components' volume and kinetic energy (KE) have previously been demonstrated in moderately dilated and depressed LV's compared to healthy subjects. We hypothesized that these 4D flow-based measures would detect even subtle LV dysfunction and remodeling. METHODS AND RESULTS: We acquired 4D flow and morphological MRI data from 26 patients with chronic ischemic heart disease with New York Heart Association (NYHA) class I and II and with no to mild LV systolic dysfunction and remodeling, and from 10 healthy controls...
2016: PloS One
D Van Twist, A J H M Houben, P W de Leeuw, A A Kroon
OBJECTIVE: Fibromuscular dysplasia (FMD) is believed to cause hypertension via similar mechanisms as atherosclerotic renal artery stenosis (ARAS), i.e. due to a decrease in renal blood flow which subsequently leads to increased renin secretion. However, given the differences in the blood pressure response to revascularization between patients with ARAS and FMD we questioned whether this is true. DESIGN AND METHOD: In 58 patients with multifocal renal artery FMD (33 unilateral) and 111 patients with high grade ARAS (64 unilateral) we selectively measured mean renal blood flow (MRBF) in both kidneys using the 133Xenon-washout-method (off medication)...
September 2016: Journal of Hypertension
Sheng Zhang, Weili Chen, Huan Tang, Quan Han, Shenqiang Yan, Xiaocheng Zhang, Qingmeng Chen, Mark Parsons, Shaoshi Wang, Min Lou
OBJECTIVE: Leptomeningeal collaterals, which affects tissue fate, are still challenging to assess. Four-dimensional CT angiography (4D CTA) originated from CT perfusion (CTP) provides the possibility of non-invasive and time-resolved assessment of leptomeningeal collateral flow. We sought to develop a comprehensive rating system to integrate the speed and extent of collateral flow on 4D CTA, and investigate its prognostic value for reperfusion therapy in acute ischemic stroke (AIS) patients...
2016: PloS One
Syed F Hussaini, David R Rutkowski, Alejandro Roldán-Alzate, Christopher J François
PURPOSE: To measure the effects of using time-resolved (TR) versus time-averaged (TA) ventricular segmentation on four-dimensional flow-sensitive (4D flow) magnetic resonance imaging (MRI) kinetic energy (KE) calculations. MATERIALS AND METHODS: Right (RV) and left (LV) ventricular KE was calculated from 4D flow MRI data acquired at 3.0T in 10 healthy volunteers and five subjects with cardiac disease using TR and TA segmentation. KE was calculated from the mass of blood within the ventricles multiplied by the velocities squared...
August 9, 2016: Journal of Magnetic Resonance Imaging: JMRI
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