scholarly journals Modeling Physiological Flow in Fontan Models With Four-Dimensional Flow Magnetic Resonance Imaging, Particle Image Velocimetry, and Arterial Spin Labeling

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
David R. Rutkowski ◽  
Rafael Medero ◽  
Timothy A. Ruesink ◽  
Alejandro Roldán-Alzate
Keyword(s):  
Arterial Spin Labeling ◽  
Phase Contrast ◽  
Particle Image ◽  
Flow Analysis ◽  
Patient Specific ◽  
Resonance Imaging ◽  
Flow Conditions ◽  
4D Flow ◽  
Image Velocimetry ◽  
Flow Mri

Abstract The Fontan procedure is a successful palliation for single ventricle defect. Yet, a number of complications still occur in Fontan patients due to abnormal blood flow dynamics, necessitating improved flow analysis and treatment methods. Phase-contrast magnetic resonance imaging (MRI) has emerged as a suitable method for such flow analysis. However, limitations on altering physiological blood flow conditions in the patient while in the MRI bore inhibit experimental investigation of a variety of factors that contribute to impaired cardiovascular health in these patients. Furthermore, resolution and flow regime limitations in phase contrast (PC) MRI pose a challenge for accurate and consistent flow characterization. In this study, patient-specific physical models were created based on nine Fontan geometries and MRI experiments mimicking low- and high-flow conditions, as well as steady and pulsatile flow, were conducted. Additionally, a particle image velocimetry (PIV)-compatible Fontan model was created and flow was analyzed with PIV, arterial spin labeling (ASL), and four-dimensional (4D) flow MRI. Differences, though nonstatistically significant, were observed between flow conditions and between patient-specific models. Large between-model variation supported the need for further improvement for patient-specific modeling on each unique Fontan anatomical configuration. Furthermore, high-resolution PIV and flow-tracking ASL data provided flow information that was not obtainable with 4D flow MRI alone.

scholarly journals Comparison of Four-Dimensional Flow Magnetic Resonance Imaging and Particle Image Velocimetry to Quantify Velocity and Turbulence Parameters

Fluids ◽  
2021 ◽  
Vol 6 (8) ◽  
pp. 277
Author(s):  
Doohyeon Kim ◽  
Jihun Kang ◽  
Ehsan Adeeb ◽  
Gyu-Han Lee ◽  
Dong Hyun Yang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Particle Image Velocimetry ◽  
Particle Image ◽  
Resonance Imaging ◽  
4D Flow Mri ◽  
4D Flow ◽  
Image Velocimetry ◽  
Flow Mri ◽  
Regression Slopes ◽  
Turbulence Parameters

Although recent advances of four-dimensional (4D) flow magnetic resonance imaging (MRI) has introduced a new way to measure Reynolds stress tensor (RST) in turbulent flows, its measurement accuracy and possible bias have remained to be revealed. The purpose of this study was to compare the turbulent flow measurement of 4D flow MRI and particle image velocimetry (PIV) in terms of velocity and turbulence quantification. Two difference flow rates of 10 and 20 L/min through a 50% stenosis were measured with both PIV and 4D flow MRI. Not only velocity through the stenosis but also the turbulence parameters such as turbulence kinetic energy and turbulence production were quantitatively compared. Results shows that 4D flow MRI velocity measurement well agreed with the that of PIV, showing the linear regression slopes of two methods are 0.94 and 0.89, respectively. Although turbulence mapping of 4D flow MRI was qualitatively agreed with that of PIV, the quantitative comparison shows that the 4D flow MRI overestimates RST showing the linear regression slopes of 1.44 and 1.66, respectively. In this study, we demonstrate that the 4D flow MRI visualize and quantify not only flow velocity and also turbulence tensor. However, further optimization of 4D flow MRI for better accuracy might be remained.

scholarly journals Numerical simulation of time-resolved 3D phase-contrast magnetic resonance imaging

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248816
Author(s):  
Thomas Puiseux ◽  
Anou Sewonu ◽  
Ramiro Moreno ◽  
Simon Mendez ◽  
Franck Nicoud
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Phase Contrast ◽  
Navier Stokes ◽  
Resonance Imaging ◽  
4D Flow Mri ◽  
4D Flow ◽  
Time Resolved ◽  
Contrast Magnetic Resonance ◽  
Flow Mri

A numerical approach is presented to efficiently simulate time-resolved 3D phase-contrast Magnetic resonance Imaging (or 4D Flow MRI) acquisitions under realistic flow conditions. The Navier-Stokes and Bloch equations are simultaneously solved with an Eulerian-Lagrangian formalism. A semi-analytic solution for the Bloch equations as well as a periodic particle seeding strategy are developed to reduce the computational cost. The velocity reconstruction pipeline is first validated by considering a Poiseuille flow configuration. The 4D Flow MRI simulation procedure is then applied to the flow within an in vitro flow phantom typical of the cardiovascular system. The simulated MR velocity images compare favorably to both the flow computed by solving the Navier-Stokes equations and experimental 4D Flow MRI measurements. A practical application is finally presented in which the MRI simulation framework is used to identify the origins of the MRI measurement errors.

Comparison of Particle Image Velocimetry and Phase Contrast MRI in a Patient-Specific Extracardiac Total Cavopulmonary Connection

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Hiroumi D. Kitajima ◽  
Kartik S. Sundareswaran ◽  
Thomas Z. Teisseyre ◽  
Garrett W. Astary ◽  
W. James Parks ◽  
...  
Keyword(s):  
Particle Image Velocimetry ◽  
Pulmonary Artery ◽  
Phase Contrast ◽  
Particle Image ◽  
Vena Cava ◽  
Patient Specific ◽  
Flow Structures ◽  
Total Cavopulmonary Connection ◽  
Image Velocimetry ◽  
Cavopulmonary Connection

Particle image velocimetry (PIV) and phase contrast magnetic resonance imaging (PC-MRI) have not been compared in complex biofluid environments. Such analysis is particularly useful to investigate flow structures in the correction of single ventricle congenital heart defects, where fluid dynamic efficiency is essential. A stereolithographic replica of an extracardiac total cavopulmonary connection (TCPC) is studied using PIV and PC-MRI in a steady flow loop. Volumetric two-component PIV is compared to volumetric three-component PC-MRI at various flow conditions. Similar flow structures are observed in both PIV and PC-MRI, where smooth flow dominates the extracardiac TCPC, and superior vena cava flow is preferential to the right pulmonary artery, while inferior vena cava flow is preferential to the left pulmonary artery. Where three-component velocity is available in PC-MRI studies, some helical flow in the extracardiac TCPC is observed. Vessel cross sections provide an effective means of validation for both experiments, and velocity magnitudes are of the same order. The results highlight similarities to validate flow in a complex patient-specific extracardiac TCPC. Additional information obtained by velocity in three components further describes the complexity of the flow in anatomic structures.

scholarly journals Enhancement of cerebrovascular 4D flow MRI velocity fields using machine learning and computational fluid dynamics simulation data

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
David R. Rutkowski ◽  
Alejandro Roldán-Alzate ◽  
Kevin M. Johnson
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Velocity Fields ◽  
Dynamics Simulation ◽  
Patient Specific ◽  
4D Flow Mri ◽  
4D Flow ◽  
Flow Phase ◽  
Flow Mri ◽  
Trained Network

AbstractBlood flow metrics obtained with four-dimensional (4D) flow phase contrast (PC) magnetic resonance imaging (MRI) can be of great value in clinical and experimental cerebrovascular analysis. However, limitations in both quantitative and qualitative analyses can result from errors inherent to PC MRI. One method that excels in creating low-error, physics-based, velocity fields is computational fluid dynamics (CFD). Augmentation of cerebral 4D flow MRI data with CFD-informed neural networks may provide a method to produce highly accurate physiological flow fields. In this preliminary study, the potential utility of such a method was demonstrated by using high resolution patient-specific CFD data to train a convolutional neural network, and then using the trained network to enhance MRI-derived velocity fields in cerebral blood vessel data sets. Through testing on simulated images, phantom data, and cerebrovascular 4D flow data from 20 patients, the trained network successfully de-noised flow images, decreased velocity error, and enhanced near-vessel-wall velocity quantification and visualization. Such image enhancement can improve experimental and clinical qualitative and quantitative cerebrovascular PC MRI analysis.

scholarly journals In vitro evaluation of cerebrospinal fluid velocity measurement in type I Chiari malformation: repeatability, reproducibility, and agreement using 2D phase contrast and 4D flow MRI

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Gwendolyn Williams ◽  
Suraj Thyagaraj ◽  
Audrey Fu ◽  
John Oshinski ◽  
Daniel Giese ◽  
...  
Keyword(s):  
Chiari Malformation ◽  
Phase Contrast ◽  
Patient Specific ◽  
Type I ◽  
4D Flow ◽  
Csf Dynamics ◽  
Flow Measurements ◽  
Repeatability And Reproducibility ◽  
Flow Techniques

Abstract Background Phase contrast magnetic resonance imaging, PC MRI, is a valuable tool allowing for non-invasive quantification of CSF dynamics, but has lacked adoption in clinical practice for Chiari malformation diagnostics. To improve these diagnostic practices, a better understanding of PC MRI based measurement agreement, repeatability, and reproducibility of CSF dynamics is needed. Methods An anatomically realistic in vitro subject specific model of a Chiari malformation patient was scanned three times at five different scanning centers using 2D PC MRI and 4D Flow techniques to quantify intra-scanner repeatability, inter-scanner reproducibility, and agreement between imaging modalities. Peak systolic CSF velocities were measured at nine axial planes using 2D PC MRI, which were then compared to 4D Flow peak systolic velocity measurements extracted at those exact axial positions along the model. Results Comparison of measurement results showed good overall agreement of CSF velocity detection between 2D PC MRI and 4D Flow (p = 0.86), fair intra-scanner repeatability (confidence intervals ± 1.5 cm/s), and poor inter-scanner reproducibility. On average, 4D Flow measurements had a larger variability than 2D PC MRI measurements (standard deviations 1.83 and 1.04 cm/s, respectively). Conclusion Agreement, repeatability, and reproducibility of 2D PC MRI and 4D Flow detection of peak CSF velocities was quantified using a patient-specific in vitro model of Chiari malformation. In combination, the greatest factor leading to measurement inconsistency was determined to be a lack of reproducibility between different MRI centers. Overall, these findings may help lead to better understanding for application of 2D PC MRI and 4D Flow techniques as diagnostic tools for CSF dynamics quantification in Chiari malformation and related diseases.

A particle image velocimetry study on the pulsatile flow characteristics in straight tubes with an asymmetric bulge

2000 ◽  
Vol 214 (5) ◽  
pp. 655-671 ◽  
Author(s):  
S C M Yu ◽  
J B Zhao
Keyword(s):  
Particle Image Velocimetry ◽  
Steady Flow ◽  
Pulsatile Flow ◽  
Flow Condition ◽  
Particle Image ◽  
Flow Characteristics ◽  
Reynolds Numbers ◽  
Working Fluid ◽  
Flow Conditions ◽  
Image Velocimetry

Flow characteristics in straight tubes with an asymmetric bulge have been investigated using particle image velocimetry (PIV) over a range of Reynolds numbers from 600 to 1200 and at a Womersley number of 22. A mixture of glycerine and water (approximately 40:60 by volume) was used as the working fluid. The study was carried out because of their relevance in some aspects of physiological flows, such as arterial flow through a sidewall aneurysm. Results for both steady and pulsatile flow conditions were obtained. It was found that at a steady flow condition, a weak recirculating vortex formed inside the bulge. The recirculation became stronger at higher Reynolds numbers but weaker at larger bulge sizes. The centre of the vortex was located close to the distal neck. At pulsatile flow conditions, the vortex appeared and disappeared at different phases of the cycle, and the sequence was only punctuated by strong forward flow behaviour (near the peak flow condition). In particular, strong flow interactions between the parent tube and the bulge were observed during the deceleration phase. Stents and springs were used to dampen the flow movement inside the bulge. It was found that the recirculation vortex could be eliminated completely in steady flow conditions using both devices. However, under pulsatile flow conditions, flow velocities inside the bulge could not be suppressed completely by both devices, but could be reduced by more than 80 per cent.

Sign in / Sign up

Export Citation Format

Share Document