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4D Flow

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https://www.readbyqxmd.com/read/28317480/novel-insights-into-complex-cardiovascular-pathologies-using-4d-flow-analysis-by-cardiovascular-magnetic-resonance-imaging
#1
Adam James Lewandowski, Betty Raman, Rajarshi Banerjee, Matteo Milanesi
BACKGROUND: It is essential that we are able to assess variations in blood flow in order to fully understand cardiovascular function in disease pathologies and for identification of individuals at long-term risk of cardiovascular disease development. Qualitative and quantitative assessments of blood flow by imaging modalities have been limited, and much of the accurate quantification has relied on invasive measures. METHODS: This review discusses how four-dimensional velocity cardiovascular magnetic resonance (4D flow CMR) offers increasing potential for the non-invasive assessment of blood flow in the heart and major blood vessels such as the aorta...
March 17, 2017: Current Pharmaceutical Design
https://www.readbyqxmd.com/read/28302143/altered-aortic-3d-hemodynamics-and-geometry-in-pediatric-marfan-syndrome-patients
#2
Roel L F van der Palen, Alex J Barker, Emilie Bollache, Julio Garcia, Michael J Rose, Pim van Ooij, Luciana T Young, Arno A W Roest, Michael Markl, Joshua D Robinson, Cynthia K Rigsby
BACKGROUND: Blood flow dynamics make it possible to better understand the development of aortopathy and cardiovascular events in patients with Marfan syndrome (MFS). Aortic 3D blood flow characteristics were investigated in relation to aortic geometry in children and adolescents with MFS. METHODS: Twenty-five MFS patients (age 15.6 ± 4.0 years; 11 females) and 21 healthy controls (age 16.0 ± 2.6 years; 12 females) underwent magnetic resonance angiography and 4D flow CMR for assessment of thoracic aortic size and 3D blood flow velocities...
March 17, 2017: Journal of Cardiovascular Magnetic Resonance
https://www.readbyqxmd.com/read/28295788/creating-hemodynamic-atlases-of-cardiac-4d-flow-mri
#3
Merih Cibis, Mariana Bustamante, Jonatan Eriksson, Carl-Johan Carlhäll, Tino Ebbers
PURPOSE: Hemodynamic atlases can add to the pathophysiological understanding of cardiac diseases. This study proposes a method to create hemodynamic atlases using 4D Flow magnetic resonance imaging (MRI). The method is demonstrated for kinetic energy (KE) and helicity density (Hd ). MATERIALS AND METHODS: Thirteen healthy subjects underwent 4D Flow MRI at 3T. Phase-contrast magnetic resonance cardioangiographies (PC-MRCAs) and an average heart were created and segmented...
March 13, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28282389/4d-flow-mri-assessment-of-right-atrial-flow-patterns-in-the-normal-heart-influence-of-caval-vein-arrangement-and-implications-for-the-patent-foramen-ovale
#4
Jehill D Parikh, Jayant Kakarla, Bernard Keavney, John J O'Sullivan, Gary A Ford, Andrew M Blamire, Kieren G Hollingsworth, Louise Coats
AIM: To investigate atrial flow patterns in the normal adult heart, to explore whether caval vein arrangement and patency of the foramen ovale (PFO) may be associated with flow pattern. MATERIALS AND METHODS: Time-resolved, three-dimensional velocity encoded magnetic resonance imaging (4D flow) was employed to assess atrial flow patterns in thirteen healthy subjects (6 male, 40 years, range 25-50) and thirteen subjects (6 male, 40 years, range 21-50) with cryptogenic stroke and patent foramen ovale (CS-PFO)...
2017: PloS One
https://www.readbyqxmd.com/read/28273332/comparison-between-model-predicted-tumor-oxygenation-dynamics-and-vascular-flow-related-doppler-indices
#5
Antonella Belfatto, Ailyn M Vidal Urbinati, Delia Ciardo, Dorella Franchi, Federica Cattani, Roberta Lazzari, Barbara A Jereczek-Fossa, Roberto Orecchia, Guido Baroni, Pietro Cerveri
PURPOSE: Mathematical modeling is a powerful and flexible method to investigate complex phenomena. It discloses the possibility of reproducing expensive as well as invasive experiments in a safe environment with limited costs. This makes it suitable to mimic tumor evolution and response to radiotherapy although the reliability of the results remains an issue. Complexity reduction is therefore a critical aspect in order to be able to compare model outcomes to clinical data. Among the factors affecting treatment efficacy, tumor oxygenation is known to play a key role in radiotherapy response...
March 8, 2017: Medical Physics
https://www.readbyqxmd.com/read/28271159/inflow-hemodynamics-evaluated-by-using-four-dimensional-flow-magnetic-resonance-imaging-and-the-size-ratio-of-unruptured-cerebral-aneurysms
#6
Kazuya Futami, Iku Nambu, Tomohiro Kitabayashi, Hiroki Sano, Kouichi Misaki, Naoyuki Uchiyama, Mitsutoshi Nakada
PURPOSE: Prediction of the rupture risk is critical for the identification of unruptured cerebral aneurysms (UCAs) eligible for invasive treatments. The size ratio (SR) is a strong morphological predictor for rupture. We investigated the relationship between the inflow hemodynamics evaluated on four-dimensional (4D) flow magnetic resonance (MR) imaging and the SR to identify specific characteristics related to UCA rupture. METHODS: We evaluated the inflow jet patterns and inflow hemodynamic parameters of 70 UCAs on 4D flow MR imaging and compared them among 23 aneurysms with an SR ≧2...
March 7, 2017: Neuroradiology
https://www.readbyqxmd.com/read/28268560/4d-lung-tumor-segmentation-via-shape-prior-and-motion-cues
#7
Jung Won Cha, Mohammad M Farhangi, Neal Dunlap, Amir Amini
Lung tumor segmentation is important for therapy in the radiation treatment of patients with thoracic malignancies. In this paper, we describe a 4D image segmentation method based on graph-cuts optimization, shape prior and optical flow. Due to small size, the location, and low contrast between the tumor and the surrounding tissue, tumor segmentation in 3D+t is challenging. We performed 4D lung tumor segmentation in 5 patients, and in each case compared the results with the expert-delineated lung nodules. In each case, 4D image segmentation took approximately ten minutes on a PC with AMD Phenom II and 32GB of memory for segmenting tumor in five phases of lung CT data...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28266062/k-t-accelerated-aortic-4d-flow-mri-in-under-two-minutes-feasibility-and-impact-of-resolution-k-space-sampling-patterns-and-respiratory-navigator-gating-on-hemodynamic-measurements
#8
Emilie Bollache, Alex J Barker, Ryan Scott Dolan, James C Carr, Pim van Ooij, Rouzbeh Ahmadian, Alex Powell, Jeremy D Collins, Julia Geiger, Michael Markl
PURPOSE: To assess the performance of highly accelerated free-breathing aortic four-dimensional (4D) flow MRI acquired in under 2 minutes compared to conventional respiratory gated 4D flow. METHODS: Eight k-t accelerated nongated 4D flow MRI (parallel MRI with extended and averaged generalized autocalibrating partially parallel acquisition kernels [PEAK GRAPPA], R = 5, TRes = 67.2 ms) using four ky -kz Cartesian sampling patterns (linear, center-out, out-center-out, random) and two spatial resolutions (SRes1 = 3...
March 7, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28242061/patient-specific-in-vitro-models-for-hemodynamic-analysis-of-congenital-heart-disease-additive-manufacturing-approach
#9
Rafael Medero, Sylvana García-Rodríguez, Christopher J François, Alejandro Roldán-Alzate
Non-invasive hemodynamic assessment of total cavopulmonary connection (TCPC) is challenging due to the complex anatomy. Additive manufacturing (AM) is a suitable alternative for creating patient-specific in vitro models for flow measurements using four-dimensional (4D) Flow MRI. These in vitro systems have the potential to serve as validation for computational fluid dynamics (CFD), simulating different physiological conditions. This study investigated three different AM technologies, stereolithography (SLA), selective laser sintering (SLS) and fused deposition modeling (FDM), to determine differences in hemodynamics when measuring flow using 4D Flow MRI...
February 7, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/28239641/macrovascular-and-microvascular-cerebral-blood-flow-in-adults-at-risk-for-alzheimer-s-disease
#10
Lindsay R Clark, Sara E Berman, Leonardo A Rivera-Rivera, Siobhan M Hoscheidt, Burcu F Darst, Corinne D Engelman, Howard A Rowley, Cynthia M Carlsson, Sanjay Asthana, Patrick Turski, Oliver Wieben, Sterling C Johnson
INTRODUCTION: Capillary hypoperfusion is reported in asymptomatic adults at-risk for Alzheimer's disease (AD), but the extent that can be explained by reduced flow in intracranial arteries is unknown. METHODS: One hundred fifty-five asymptomatic adults enriched for AD risk (mean age 61 years) completed arterial spin labeling (pcASL) and 4D-flow MRI sequences. Voxel-wise regression models investigated the relationship between mean flow in bilateral cerebral arteries and capillary perfusion, and tested potential moderators of this relationship...
2017: Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring
https://www.readbyqxmd.com/read/28226737/4d-lung-tumor-segmentation-via-shape-prior-and-motion-cues
#11
Jung Won Cha, Mohammad M Farhangi, Neal Dunlap, Amir Amini, Jung Won Cha, Mohammad M Farhangi, Neal Dunlap, Amir Amini, Jung Won Cha, Amir Amini, Neal Dunlap, Mohammad M Farhangi
Lung tumor segmentation is important for therapy in the radiation treatment of patients with thoracic malignancies. In this paper, we describe a 4D image segmentation method based on graph-cuts optimization, shape prior and optical flow. Due to small size, the location, and low contrast between the tumor and the surrounding tissue, tumor segmentation in 3D+t is challenging. We performed 4D lung tumor segmentation in 5 patients, and in each case compared the results with the expert-delineated lung nodules. In each case, 4D image segmentation took approximately ten minutes on a PC with AMD Phenom II and 32GB of memory for segmenting tumor in five phases of lung CT data...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28225577/image-based-background-phase-error-correction-in-4d-flow-mri-revisited
#12
Julia Busch, Daniel Giese, Sebastian Kozerke
PURPOSE: To correct background phase errors in phase-contrast magnetic resonance imaging (MRI), image-based correction by referencing through stationary tissue is widely used. The aim of the present study was a detailed assessment of background phase errors in 4D Flow MRI and limitations of image-based correction. MATERIALS AND METHODS: In a phantom study, 4D Flow MRI data were acquired for typical settings on two clinical 3T MR systems. Background errors were analyzed with respect to their spatial order and minimum requirements regarding the signal-to-noise ratio (SNR) and the amount of stationary tissue for image-based correction were assessed...
February 22, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28185475/4d-flow-magnetic-resonance-imaging-role-in-pediatric-congenital-heart-disease
#13
Claire M Lawley, Kathryn M Broadhouse, Fraser M Callaghan, David S Winlaw, Gemma A Figtree, Stuart M Grieve
Imaging-based evaluation of cardiac structure and function remains paramount in the diagnosis and monitoring of congenital heart disease in childhood. Accurate measurements of intra- and extracardiac hemodynamics are required to inform decision making, allowing planned timing of interventions prior to deterioration of cardiac function. Four-dimensional flow magnetic resonance imaging is a nonionizing noninvasive technology that allows accurate and reproducible delineation of blood flow at any anatomical location within the imaging volume of interest, and also permits derivation of physiological parameters such as kinetic energy and wall shear stress...
January 1, 2017: Asian Cardiovascular & Thoracic Annals
https://www.readbyqxmd.com/read/28184976/decreased-diastolic-ventricular-kinetic-energy-in-young-patients-with-fontan-circulation-demonstrated-by-four-dimensional-cardiac-magnetic-resonance-imaging
#14
Pia Sjöberg, Einar Heiberg, Pär Wingren, Jens Ramgren Johansson, Torsten Malm, Håkan Arheden, Petru Liuba, Marcus Carlsson
Four-dimensional (4D) flow magnetic resonance imaging (MRI) enables quantification of kinetic energy (KE) in intraventricular blood flow. This provides a novel way to understand the cardiovascular physiology of the Fontan circulation. In this study, we aimed to quantify the KE in functional single ventricles. 4D flow MRI was acquired in eleven patients with Fontan circulation (median age 12 years, range 3-29) and eight healthy volunteers (median age 26 years, range 23-36). Follow-up MRI after surgical or percutaneous intervention was performed in 3 patients...
February 10, 2017: Pediatric Cardiology
https://www.readbyqxmd.com/read/28174322/4d-microvascular-analysis-reveals-that-regenerative-angiogenesis-in-ischemic-muscle-produces-a-flawed-microcirculation
#15
John-Michael Arpino, Zengxuan Nong, Fuyan Li, Hao Yin, Nour W Ghonaim, Stephanie Milkovich, Brittany Balint, Caroline O'Neil, Graham M Fraser, Daniel Goldman, Christopher G Ellis, J G Pickering
RATIONALE: Angiogenesis occurs following ischemic injury to skeletal muscle and enhancing this response has been a therapeutic goal. However, to appropriately deliver oxygen, a precisely organized and exquisitely responsive microcirculation must form. Whether these network attributes exist in a regenerated microcirculation is unknown and methodologies for answering this have been lacking. OBJECTIVE: To develop 4D methodologies for elucidating microarchitecture and function of the reconstructed microcirculation in skeletal muscle...
February 7, 2017: Circulation Research
https://www.readbyqxmd.com/read/28152259/four-dimensional-phase-contrast-vastly-undersampled-isotropic-projection-reconstruction-4d-pc-vipr-mr-evaluation-of-the-renal-arteries-in-transplant-recipients-preliminary-results
#16
Daisuke Motoyama, Yasuo Ishii, Yasuo Takehara, Masataka Sugiyama, Wang Yang, Hatsuko Nasu, Takasuke Ushio, Yuko Hirose, Naoki Ohishi, Tetsuya Wakayama, Hiroyuki Kabasawa, Kevin Johnson, Oliver Wieben, Harumi Sakahara, Seiichiro Ozono
PURPOSE: To assess the performance of four-dimensional phase-contrast vastly undersampled isotropic projection reconstruction (4D PC-VIPR) at 3.0T in depicting intrarenal arteries compared with computed tomography angiography (CTA), and its correlation with arterial flowmetry in comparison with Doppler ultrasonography (DUS). MATERIALS AND METHODS: In our prospective single-arm study, subjects were 25 patients who underwent renal transplant-related surgery at our hospital between July 2011 and June 2015...
February 2, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28152256/accelerated-dual-venc-4d-flow-mri-for-neurovascular-applications
#17
Susanne Schnell, Sameer A Ansari, Can Wu, Julio Garcia, Ian G Murphy, Ozair A Rahman, Amir A Rahsepar, Maria Aristova, Jeremy D Collins, James C Carr, Michael Markl
PURPOSE: To improve velocity-to-noise ratio (VNR) and dynamic velocity range of 4D flow magnetic resonance imaging (MRI) by using dual-velocity encoding (dual-venc) with k-t generalized autocalibrating partially parallel acquisition (GRAPPA) acceleration. MATERIALS AND METHODS: A dual-venc 4D flow MRI sequence with k-t GRAPPA acceleration was developed using a shared reference scan followed by three-directional low- and high-venc scans (repetition time / echo time / flip angle = 6...
February 2, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28148318/utility-of-4d-flow-mapping-in-eisenmenger-syndrome-with-pulmonary-atresia
#18
Soha Romeih, Heba Aguib, Magdi Yacoub
Management of patients with Eisenmenger syndrome with pulmonary atresia is challenging because of the complexity of the structure-function relationship of the components of the syndrome. Multi-modality imaging including cardiac magnetic resonance (CMR) 4D Flow offers unprecedented opportunities to unravel, at least in part, some of these components, and thus help in the management of these patients. In this study, we describe the use of these integrated methods with particular reference to CMR 4D Flow in a patient with Eisenmenger syndrome and pulmonary atresia and outline both the utility and the limitations...
December 2016: Cardiology in the Young
https://www.readbyqxmd.com/read/28144400/cutting-edge-clinical-applications-in-cardiovascular-magnetic-resonance
#19
EDITORIAL
Carlo N De Cecco, Giuseppe Muscogiuri, Akos Varga-Szemes, U Joseph Schoepf
Today, the use of cardiovascular magnetic resonance (CMR) is widespread in clinical practice. The increased need to evaluate of subtle myocardial changes, coronary artery anatomy, and hemodynamic assessment has prompted the development of novel CMR techniques including T1 and T2 mapping, non-contrast angiography and four dimensional (4D) flow. T1 mapping is suitable for diagnosing pathologies affecting extracellular volume such as myocarditis, diffuse myocardial fibrosis and amyloidosis, and is a promising diagnostic tool for patients with iron overload and Fabry disease...
January 28, 2017: World Journal of Radiology
https://www.readbyqxmd.com/read/28113417/enhancing-the-velocity-data-from-4d-flow-mr-images-by-reducing-its-divergence
#20
Joaquin Mura, A Matias Pino, Julio Sotelo, Israel Valverde, Cristian Tejos, Marcelo Andia, Pablo Irarrazaval, Sergio Uribe
Velocity measurements from 4D flow MRI are prone to be affected by several imperfections of the MR system. Assuming that blood is incompressible, we propose a novel method for enhancing the velocity field by reducing its divergence. To enhance the velocity data, we added a corrector velocity to each voxel such that the divergence is minimized. The method was validated using an analytical Womersley flow model for different settings of resolution and noise levels. The performance of the proposed method was also assessed in volunteers and patients...
May 18, 2016: IEEE Transactions on Medical Imaging
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