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4D Flow

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https://www.readbyqxmd.com/read/28645326/improving-visualization-of-4d-flow-cardiovascular-magnetic-resonance-with-four-dimensional-angiographic-data-generation-of-a-4d-phase-contrast-magnetic-resonance-cardioangiography-4d-pc-mrca
#1
Mariana Bustamante, Vikas Gupta, Carl-Johan Carlhäll, Tino Ebbers
Magnetic Resonance Angiography (MRA) and Phase-Contrast MRA (PC-MRA) approaches used for assessment of cardiovascular morphology typically result in data containing information from the entire cardiac cycle combined into one 2D or 3D image. Information specific to each timeframe of the cardiac cycle is, however, lost in this process. This study proposes a novel technique, called Phase-Contrast Magnetic Resonance CardioAngiography (4D PC-MRCA), that utilizes the full potential of 4D Flow CMR when generating temporally resolved PC-MRA data to improve visualization of the heart and major vessels throughout the cardiac cycle...
June 23, 2017: Journal of Cardiovascular Magnetic Resonance
https://www.readbyqxmd.com/read/28640394/in-scan-and-scan-rescan-assessment-of-lv-in-and-outflow-volumes-by-4d-flow-mri-versus-2d-planimetry
#2
Vivian P Kamphuis, Roel L F van der Palen, Patrick J H de Koning, Mohammed S M Elbaz, Rob J van der Geest, Albert de Roos, Arno A W Roest, Jos J M Westenberg
PURPOSE: To evaluate the in-scan and scan-rescan consistency of left ventricular (LV) in- and outflow assessment from 1) 2D planimetry; 2) 4D flow magnetic resonance imaging (MRI) with retrospective valve tracking, and 3) 4D flow MRI with particle tracing. MATERIALS AND METHODS: Ten healthy volunteers (age 27 ± 3 years) underwent multislice cine short-axis planimetry and whole-heart 4D flow MRI on a 3T MRI scanner twice with repositioning between the scans...
June 22, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28624566/4d-phase-contrast-mri-protocol-optimization-using-patient-specific-3d-printed-replicas-for-in-vivo-imaging-before-and-after-flow-diverter-placement
#3
Christof Karmonik, Jeff R Anderson, Saba Elias, Richard Klucznik, Orlando Diaz, Y Jonathan Zhang, Robert G Grossman, Gavin W Britz
PURPOSE: Hemodynamics in cerebral aneurysms is currently investigated towards its clinical efficacy using non-standardized computational simulation techniques. At the same time, flow patterns and velocities are accessible by 4D phase contrast magnetic resonance imaging (4D pcMRI). Complexity of protocol design and imaging duration has limited the use of this technique in clinical imaging. A new approach is presented to overcome these limitations. MATERIAL AND METHODS: 3D replicas of two cerebral aneurysms were fabricated by fused deposition prototyping (3D printing) and imaged using 4D pcMRI while connected to an MRI compatible continuous flow loop...
June 14, 2017: World Neurosurgery
https://www.readbyqxmd.com/read/28622338/multi-phase-simultaneous-segmentation-of-tumor-in-lung-4d-ct-data-with-context-information
#4
Zhengwen Shen, Huafeng Wang, Weiwen Xi, Xiaogang Deng, Jin Chen, Yu Zhang
Lung 4D computed tomography (4D-CT) plays an important role in high-precision radiotherapy because it characterizes respiratory motion, which is crucial for accurate target definition. However, the manual segmentation of a lung tumor is a heavy workload for doctors because of the large number of lung 4D-CT data slices. Meanwhile, tumor segmentation is still a notoriously challenging problem in computer-aided diagnosis. In this paper, we propose a new method based on an improved graph cut algorithm with context information constraint to find a convenient and robust approach of lung 4D-CT tumor segmentation...
2017: PloS One
https://www.readbyqxmd.com/read/28620320/abnormal-haemodynamic-flow-patterns-in-bicuspid-pulmonary-valve-disease
#5
Malenka M Bissell, Margaret Loudon, Stefan Neubauer, Saul G Myerson
Abnormal flow patterns in the aortas of those with bicuspid aortic valves (BAVs) are increasingly recognized as important in the pathogenesis of aortic dilatation but pulmonary flow patterns in bicuspid pulmonary valves have not been studied. Bicuspid pulmonary valve disease is rare and a small numbers of case reports describe concomitant pulmonary artery dilation similar to the dilation of the ascending aorta, which is often seen in BAVs disease. We examined three cases of bicuspid pulmonary valve disease, 10 healthy volunteers and 10 patients with BAV disease but a tricuspid pulmonary valve...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28619493/dynamic-4d-cta-for-neuro-vascular-pathologies-a-case-series
#6
Ahmed Alnemari, Tarek R Mansour, Mohamad Bazerbashi, Mark Buehler, Jason Schroeder, Daniel Gaudin
BACKGROUND: The aim of this article is to illustrate, summarize, and review the multifaceted application of four-dimensional computed tomography angiography (4D-CTA) in the characterization and diagnosis of various cerebrovascular and tumor-associated vascular pathologies through the presentation of clinical cases including acute/chronic stroke, arteriovenous malformations, aneurysm, moya-moya disease, and the hypervascularity associated with a tumor and its relationship to pre-operative embolization...
June 12, 2017: World Neurosurgery
https://www.readbyqxmd.com/read/28617686/imaging-adult-patients-with-coarctation-of-the-aorta
#7
Akanksha N Thakkar, Ponraj Chinnadurai, C Huie Lin
PURPOSE OF REVIEW: To provide an overview of current recommendations and techniques used to image coarctations of the aorta. RECENT FINDINGS: Imaging of coarctation of the aorta in adults is moving away from conventional techniques such as echocardiography and invasive angiography. Echocardiography may assist in making the diagnosis but is limited in its ability to quantify the severity of coarctations. Current guidelines recommend that every patient with a coarctation must undergo a computed tomography (CT) or MRI scan for accurate delineation of morphology...
June 15, 2017: Current Opinion in Cardiology
https://www.readbyqxmd.com/read/28611119/turbulent-kinetic-energy-assessed-by-multipoint-4-dimensional-flow-magnetic-resonance-imaging-provides-additional-information-relative-to-echocardiography-for-the-determination-of-aortic-stenosis-severity
#8
Christian Binter, Alexander Gotschy, Simon H Sündermann, Michelle Frank, Felix C Tanner, Thomas F Lüscher, Robert Manka, Sebastian Kozerke
BACKGROUND: Turbulent kinetic energy (TKE), assessed by 4-dimensional (4D) flow magnetic resonance imaging, is a measure of energy loss in disturbed flow as it occurs, for instance, in aortic stenosis (AS). This work investigates the additional information provided by quantifying TKE for the assessment of AS severity in comparison to clinical echocardiographic measures. METHODS AND RESULTS: Fifty-one patients with AS (67±15 years, 20 female) and 10 healthy age-matched controls (69±5 years, 5 female) were prospectively enrolled to undergo multipoint 4D flow magnetic resonance imaging...
June 2017: Circulation. 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
#9
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/28598243/advances-in-arterial-spin-labelling-mri-methods-for-measuring-perfusion-and-collateral-flow
#10
Matthias Jp van Osch, Wouter M Teeuwisse, Zhensen Chen, Yuriko Suzuki, Michael Helle, Sophie Schmid
With the publication in 2015 of the consensus statement by the perfusion study group of the International Society for Magnetic Resonance in Medicine (ISMRM) and the EU-COST action 'ASL in dementia' on the implementation of arterial spin labelling MRI (ASL) in a clinical setting, the development of ASL can be considered to have become mature and ready for clinical prime-time. In this review article new developments and remaining issues will be discussed, especially focusing on quantification of ASL as well as on new technological developments of ASL for perfusion imaging and flow territory mapping...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28592851/left-ventricular-hemodynamic-forces-as-a-marker-of-mechanical-dyssynchrony-in-heart-failure-patients-with-left-bundle-branch-block
#11
Jonatan Eriksson, Jakub Zajac, Urban Alehagen, Ann F Bolger, Tino Ebbers, Carl-Johan Carlhäll
Left bundle branch block (LBBB) causes left ventricular (LV) dyssynchrony which is often associated with heart failure. A significant proportion of heart failure patients do not demonstrate clinical improvement despite cardiac resynchronization therapy (CRT). How LBBB-related effects on LV diastolic function may contribute to those therapeutic failures has not been clarified. We hypothesized that LV hemodynamic forces calculated from 4D flow MRI could serve as a marker of diastolic mechanical dyssynchrony in LBBB hearts...
June 7, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28580809/cardiovascular-imaging-environment-will-the-future-be-cloud-based
#12
Nadine Kawel-Boehm, David A Bluemke
In cardiovascular CT and MR imaging large datasets have to be stored, post-processed, analyzed and distributed. Beside basic assessment of volume and function in cardiac magnetic resonance imaging e.g., more sophisticated quantitative analysis is requested requiring specific software. Several institutions cannot afford various types of software and provide expertise to perform sophisticated analysis. Areas covered: Various cloud services exist related to data storage and analysis specifically for cardiovascular CT and MR imaging...
June 13, 2017: Expert Review of Medical Devices
https://www.readbyqxmd.com/read/28577904/merging-computational-fluid-dynamics-and-4d-flow-mri-using-proper-orthogonal-decomposition-and-ridge-regression
#13
Ali Bakhshinejad, Ahmadreza Baghaie, Alireza Vali, David Saloner, Vitaliy L Rayz, Roshan M D'Souza
Time resolved phase-contrast magnetic resonance imaging 4D-PCMR (also called 4D Flow MRI) data while capable of non-invasively measuring blood velocities, can be affected by acquisition noise, flow artifacts, and resolution limits. In this paper, we present a novel method for merging 4D Flow MRI with computational fluid dynamics (CFD) to address these limitations and to reconstruct de-noised, divergence-free high-resolution flow-fields. Proper orthogonal decomposition (POD) is used to construct the orthonormal basis of the local sampling of the space of all possible solutions to the flow equations both at the low-resolution level of the 4D Flow MRI grid and the high-level resolution of the CFD mesh...
June 14, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/28577254/the-value-of-whole-brain-ct-perfusion-imaging-and-ct-angiography-using-a-320-slice-ct-scanner-in-the-diagnosis-of-mci-and-ad-patients
#14
Bo Zhang, Guo-Jun Gu, Hong Jiang, Yi Guo, Xing Shen, Bo Li, Wei Zhang
OBJECTIVES: To validate the value of whole-brain computed tomography perfusion (CTP) and CT angiography (CTA) in the diagnosis of mild cognitive impairment (MCI) and Alzheimer's disease (AD). METHODS: Whole-brain CTP and four-dimensional CT angiography (4D-CTA) images were acquired in 30 MCI, 35 mild AD patients, 35 moderate AD patients, 30 severe AD patients and 50 normal controls (NC). Cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time to peak (TTP), and correlation between CTP and 4D-CTA were analysed...
June 2, 2017: European Radiology
https://www.readbyqxmd.com/read/28570032/free-breathing-pediatric-chest-mri-performance-of-self-navigated-golden-angle-ordered-conical-ultrashort-echo-time-acquisition
#15
Evan J Zucker, Joseph Y Cheng, Anshul Haldipur, Michael Carl, Shreyas S Vasanawala
PURPOSE: To assess the feasibility and performance of conical k-space trajectory free-breathing ultrashort echo time (UTE) chest magnetic resonance imaging (MRI) versus four-dimensional (4D) flow and effects of 50% data subsampling and soft-gated motion correction. MATERIALS AND METHODS: Thirty-two consecutive children who underwent both 4D flow and UTE ferumoxytol-enhanced chest MR (mean age: 5.4 years, range: 6 days to 15.7 years) in one 3T exam were recruited...
June 1, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28556277/distribution-of-blood-flow-velocity-in-the-normal-aorta-effect-of-age-and-gender
#16
Julio Garcia, Roel L F van der Palen, Emilie Bollache, Kelly Jarvis, Michael J Rose, Alex J Barker, Jeremy D Collins, James C Carr, Joshua Robinson, Cynthia K Rigsby, Michael Markl
PURPOSE: To apply flow distribution analysis in the entire aorta across a wide age range from pediatric to adult subjects. MATERIAL AND METHODS: In all, 98 healthy subjects (age 9-78 years, 41 women) underwent 4D flow MRI at 1.5T and 3T for the assessment of 3D blood flow in the thoracic aorta. Subjects were categorized into age groups: group 1 (n = 9, 5 women): 9-15 years; group 2 (n = 13, 8 women): 16-20 years; group 3 (n = 27, 14 women): 21-39 years; group 4 (n = 40, 11 women): 40-59 years; group 5 (n = 9, 3 women): >60 years...
May 26, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28513326/the-effects-of-blood-flow-restricted-electrostimulation-on-strength-hypertrophy
#17
Joshua Slysz, Jamie F Burr
CONTEXT: The combined effect of neuromuscular electrical muscle stimulation (NMES) and blood flow restriction (BFR) on muscle mass and strength has not been thoroughly investigated. OBJECTIVE: To examine the effects of combined and independent BFR and a low-intensity NMES on skeletal muscle adaptation. DESIGN: Exploratory Study. SETTING: Laboratory. PARTICIPANTS: Twenty recreationally active subjects...
May 17, 2017: Journal of Sport Rehabilitation
https://www.readbyqxmd.com/read/28508399/hdliveflow-with-spatiotemporal-image-correlation-for-the-diagnosis-of-congenital-heart-disease
#18
Megumi Ito, Mohamed Ahmed Mostafa AboEllail, Kenta Yamamoto, Kenji Kanenishi, Hirokazu Tanaka, Hiroshi Masaoka, Toshiyuki Hata
With the latest advancement of three-dimensional (3D)/four-dimensional (4D) ultrasound machines, HDliveFlow will facilitate more precise evaluations of the fetal and placental circulations [1-5] and gynecologic disorders [6-10]. HDliveFlow silhouette mode is the latest technology to demonstrate vitreous-like clarity of the blood flow. This technique has the ability to preserve and delineate the outline and borders of the blood flow, while showing its core as transparent.
May 16, 2017: Ultrasound in Obstetrics & Gynecology
https://www.readbyqxmd.com/read/28470915/comparison-of-fast-acquisition-strategies-in-whole-heart-four-dimensional-flow-cardiac-mr-two-center-1-5-tesla-phantom-and-in-vivo-validation-study
#19
Pankaj Garg, Jos J M Westenberg, Pieter J van den Boogaard, Peter P Swoboda, Rahoz Aziz, James R J Foley, Graham J Fent, F G J Tyl, L Coratella, Mohammed S M ElBaz, R J van der Geest, David M Higgins, John P Greenwood, Sven Plein
PURPOSE: To validate three widely-used acceleration methods in four-dimensional (4D) flow cardiac MR; segmented 4D-spoiled-gradient-echo (4D-SPGR), 4D-echo-planar-imaging (4D-EPI), and 4D-k-t Broad-use Linear Acquisition Speed-up Technique (4D-k-t BLAST). MATERIALS AND METHODS: Acceleration methods were investigated in static/pulsatile phantoms and 25 volunteers on 1.5 Tesla MR systems. In phantoms, flow was quantified by 2D phase-contrast (PC), the three 4D flow methods and the time-beaker flow measurements...
May 4, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28463524/journal-club-four-dimensional-flow-mri-based-splenic-flow-index-for-predicting-cirrhosis-associated-hypersplenism
#20
Eric J Keller, Laura Kulik, Zoran Stankovic, Robert J Lewandowski, Riad Salem, James C Carr, Susanne Schnell, Michael Markl, Jeremy D Collins
OBJECTIVE: The objective of this study is to evaluate the ability of spleen volume, blood flow, and an index incorporating multiple measures to predict cirrhosis-associated hypersplenism. MATERIALS AND METHODS: A total of 39 patients (14 women and 25 men; mean [± SD] age, 52 ± 10 years) with cirrhosis and sequelae of portal hypertension underwent 4D flow MRI and anatomic 3-T MRI performed before and after contrast administration. Unenhanced 4D flow MRI was used to assess abdominal hemodynamics, and splenic volumes were measured on T1-weighted gradient-recalled echo MRI...
May 2, 2017: AJR. American Journal of Roentgenology
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