1
|
Rauh P, Benk C, Beyersdorf F, Russe M. Determination of local flow ratios and velocities in a femoral venous cannula with computational fluid dynamics and 4D flow-sensitive magnetic resonance imaging: A method validation. Artif Organs 2020; 45:506-515. [PMID: 33185904 DOI: 10.1111/aor.13859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 09/09/2020] [Accepted: 10/08/2020] [Indexed: 11/28/2022]
Abstract
Cannulas with multi-staged side holes are the method of choice for femoral cannulation in extracorporeal therapies today. A variety of differently designed products is available on the market. While the preferred tool for the performance assessment of such cannulas are pressure-flow curves, little is known about the flow and velocity distribution. Within this work flow and velocity patterns of a femoral venous cannula with multi-staged side holes were investigated. A mock circulation loop for cannula performance evaluation was built and reproduced using a computer-aided design system. With computational fluid dynamics, volume flows and fluid velocities were determined quantitatively and visually with hole-based precision. In order to ensure the correctness of the flow simulation, the results were subsequently validated by determining the same parameters with four-dimensional flow-sensitive magnetic resonance imaging. Measurement data and numerical solution differed 7% on average throughout the data set for the examined parameters. The highest inflow and velocity were detected at the most proximal holes, where half of the total volume flow enters the cannula. At every hole stage a Y-shaped inflow profile was detected, forming a centered stream in the middle of the cannula. Simultaneously, flow separation creates zones with significant lower flow velocities. Numerical simulation, validated with four-dimensional flow-sensitive magnetic resonance imaging, is a valuable tool to examine flow and velocity distributions of femoral venous cannulas with hole-based accuracy. Flow and velocity distribution in such cannulas are not ideal. Based on this work future cannulas can be effectively optimized.
Collapse
Affiliation(s)
- Patrick Rauh
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Research & Development, Xenios AG, Heilbronn, Germany
| | - Christoph Benk
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Department of Cardiovascular Surgery, Heart Center University Freiburg, Freiburg, Germany
| | - Friedhelm Beyersdorf
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Department of Cardiovascular Surgery, Heart Center University Freiburg, Freiburg, Germany
| | - Maximilian Russe
- Department of Radiology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| |
Collapse
|
2
|
Lenz A, Petersen J, Riedel C, Weinrich JM, Kooijman H, Schoennagel BP, Adam G, von Kodolitsch Y, Reichenspurner H, Girdauskas E, Bannas P. 4D flow cardiovascular magnetic resonance for monitoring of aortic valve repair in bicuspid aortic valve disease. J Cardiovasc Magn Reson 2020; 22:29. [PMID: 32354361 PMCID: PMC7193544 DOI: 10.1186/s12968-020-00608-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 02/17/2020] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Aortic valve repair has become a treatment option for adults with symptomatic bicuspid (BAV) or unicuspid (UAV) aortic valve insufficiency. Our aim was to demonstrate the feasibility of 4D flow cardiovascular magnetic resonance (CMR) to assess the impact of aortic valve repair on changes in blood flow dynamics in patients with symptomatic BAV or UAV. METHODS Twenty patients with adult congenital heart disease (median 35 years, range 18-64; 16 male) and symptomatic aortic valve regurgitation (15 BAV, 5 UAV) were prospectively studied. All patients underwent 4D flow CMR before and after aortic valve repair. Aortic valve regurgitant fraction and systolic peak velocity were estimated. The degree of helical and vortical flow was evaluated according to a 3-point scale. Relative flow displacement and wall shear stress (WSS) were quantified at predefined levels in the thoracic aorta. RESULTS All patients underwent successful aortic valve repair with a significant reduction of aortic valve regurgitation (16.7 ± 9.8% to 6.4 ± 4.4%, p < 0.001) and systolic peak velocity (2.3 ± 0.9 to 1.9 ± 0.4 m/s, p = 0.014). Both helical flow (1.6 ± 0.6 vs. 0.9 ± 0.5, p < 0.001) and vortical flow (1.2 ± 0.8 vs. 0.5 ± 0.6, p = 0.002) as well as both flow displacement (0.3 ± 0.1 vs. 0.25 ± 0.1, p = 0.031) and WSS (0.8 ± 0.2 N/m2 vs. 0.5 ± 0.2 N/m2, p < 0.001) in the ascending aorta were significantly reduced after aortic valve repair. CONCLUSIONS 4D flow CMR allows assessment of the impact of aortic valve repair on changes in blood flow dynamics in patients with bicuspid aortic valve disease.
Collapse
Affiliation(s)
- Alexander Lenz
- Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany.
| | - Johannes Petersen
- Department of Cardiovascular Surgery, University Heart Center, Hamburg, Germany
| | - Christoph Riedel
- Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | - Julius M Weinrich
- Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | | | - Bjoern P Schoennagel
- Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | - Gerhard Adam
- Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | | | | | - Evaldas Girdauskas
- Department of Cardiovascular Surgery, University Heart Center, Hamburg, Germany
| | - Peter Bannas
- Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| |
Collapse
|
3
|
Annio G, Torii R, Ariff B, O'Regan DP, Muthurangu V, Ducci A, Tsang V, Burriesci G. Enhancing Magnetic Resonance Imaging With Computational Fluid Dynamics. ACTA ACUST UNITED AC 2019. [DOI: 10.1115/1.4045493] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Abstract
The analysis of the blood flow in the great thoracic arteries does provide valuable information about the cardiac function and can diagnose the potential development of vascular diseases. Flow-sensitive four-dimensional flow cardiovascular magnetic resonance imaging (4D flow CMR) is often used to characterize patients' blood flow in the clinical environment. Nevertheless, limited spatial and temporal resolution hinders a detailed assessment of the hemodynamics. Computational fluid dynamics (CFD) could expand this information and, integrated with experimental velocity field, enable to derive the pressure maps. However, the limited resolution of the 4D flow CMR and the simplifications of CFD modeling compromise the accuracy of the computed flow parameters. In this article, a novel approach is proposed, where 4D flow CMR and CFD velocity fields are integrated synergistically to obtain an enhanced MR imaging (EMRI). The approach was first tested on a two-dimensional (2D) portion of a pipe, to understand the behavior of the parameters of the model in this novel framework, and afterwards in vivo, to apply it to the analysis of blood flow in a patient-specific human aorta. The outcomes of EMRI are assessed by comparing the computed velocities with the experimental one. The results demonstrate that EMRI preserves flow structures while correcting for experimental noise. Therefore, it can provide better insights into the hemodynamics of cardiovascular problems, overcoming the limitations of MRI and CFD, even when considering a small region of interest. EMRI confirmed its potential to provide more accurate noninvasive estimation of major cardiovascular risk predictors (e.g., flow patterns, endothelial shear stress) and become a novel diagnostic tool.
Collapse
Affiliation(s)
- Giacomo Annio
- Department Medical Physics and Bioengineering, University College London, Torrington Place, London WC1E 7JE, UK
| | - Ryo Torii
- UCL Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
| | - Ben Ariff
- MRC London Institute of Medical Sciences, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Declan P. O'Regan
- MRC London Institute of Medical Sciences, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Vivek Muthurangu
- UCL Institute of Cardiovascular Science, Centre for Cardiovascular Imaging, University College London, 62 Huntley Street, Fitzrovia, London WC1E 6DD, UK; Great Ormond Street Hospital for Children, Great Ormond Street, Holborn, London WC1N 3JH, UK
| | - Andrea Ducci
- UCL Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
| | - Victor Tsang
- Cardiothoracic Surgery Unit, Great Ormond Street Hospital for Children, Great Ormond Street, Holborn, London WC1N 3JH, UK
| | - Gaetano Burriesci
- UCL Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK; Ri.MED Foundation, Via Bandiera, 11, Palermo 90133, Italy
| |
Collapse
|
4
|
Feiger B, Vardhan M, Gounley J, Mortensen M, Nair P, Chaudhury R, Frakes D, Randles A. Suitability of lattice Boltzmann inlet and outlet boundary conditions for simulating flow in image-derived vasculature. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2019; 35:e3198. [PMID: 30838793 PMCID: PMC7605305 DOI: 10.1002/cnm.3198] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 12/18/2018] [Accepted: 03/03/2019] [Indexed: 06/09/2023]
Abstract
The lattice Boltzmann method (LBM) is a popular alternative to solving the Navier-Stokes equations for modeling blood flow. When simulating flow using the LBM, several choices for inlet and outlet boundary conditions exist. While boundary conditions in the LBM have been evaluated in idealized geometries, there have been no extensive comparisons in image-derived vasculature, where the geometries are highly complex. In this study, the Zou-He (ZH) and finite difference (FD) boundary conditions were evaluated in image-derived vascular geometries by comparing their stability, accuracy, and run times. The boundary conditions were compared in four arteries: a coarctation of the aorta, dissected aorta, femoral artery, and left coronary artery. The FD boundary condition was more stable than ZH in all four geometries. In general, simulations using the ZH and FD method showed similar convergence rates within each geometry. However, the ZH method proved to be slightly more accurate compared with experimental flow using three-dimensional printed vasculature. The total run times necessary for simulations using the ZH boundary condition were significantly higher as the ZH method required a larger relaxation time, grid resolution, and number of time steps for a simulation representing the same physiological time. Finally, a new inlet velocity profile algorithm is presented for complex inlet geometries. Overall, results indicated that the FD method should generally be used for large-scale blood flow simulations in image-derived vasculature geometries. This study can serve as a guide to researchers interested in using the LBM to simulate blood flow.
Collapse
Affiliation(s)
- Bradley Feiger
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Madhurima Vardhan
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - John Gounley
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Matthew Mortensen
- Department of Biomedical Engineering, Arizona State University, Tempe, AZ, USA
| | - Priya Nair
- Department of Biomedical Engineering, Arizona State University, Tempe, AZ, USA
| | - Rafeed Chaudhury
- Department of Biomedical Engineering, Arizona State University, Tempe, AZ, USA
| | - David Frakes
- Department of Biomedical Engineering, Arizona State University, Tempe, AZ, USA
| | - Amanda Randles
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| |
Collapse
|
5
|
Abstract
In this work, we present a numerical investigation of blood flow in a portion of the human vascular system. More precisely, the present work analyzed the blood flow in the upper portion of the aorta. The aorta and its ramified blood vessels are surrounded by the cardiac muscle. The blood flow generates pressure on the internal surfaces of the artery and its ramifications, thereby causing deformation of the cardiac muscle. The numerical analysis used the Navier–Stokes equations as the governing equations of blood flow for the calculation of the velocity field and pressure distribution in the blood. The neo-Hookean hyperelastic model was used for the description of the behavior of the vessel walls. The velocity and pressure distributions were analyzed. The deformation of the vessel was also investigated. The numerical results could be used to better understand and predict the factors that trigger cardiovascular diseases and distortions of the aorta and as a diagnostic tool in clinical applications.
Collapse
|
6
|
Gomez A, Marčan M, Arthurs CJ, Wright R, Youssefi P, Jahangiri M, Figueroa CA. Optimal B-spline Mapping of Flow Imaging Data for Imposing Patient-specific Velocity Profiles in Computational Hemodynamics. IEEE Trans Biomed Eng 2018; 66:10.1109/TBME.2018.2880606. [PMID: 30561336 PMCID: PMC6594901 DOI: 10.1109/tbme.2018.2880606] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE We propose a novel method to map patient-specific blood velocity profiles obtained from imaging data such as 2D flow MRI or 3D colour Doppler ultrasound) to geometric vascular models suitable to perform CFD simulations of haemodynamics. We describe the implementation and utilisation of the method within an open-source computational hemodynamics simulation software (CRIMSON). METHODS The proposed method establishes point-wise correspondences between the contour of a fixed geometric model and time-varying contours containing the velocity image data, from which a continuous, smooth and cyclic deformation field is calculated. Our methodology is validated using synthetic data, and demonstrated using two different in-vivo aortic velocity datasets: a healthy subject with normal tricuspid valve and a patient with bicuspid aortic valve. RESULTS We compare our method with the state-of-the-art Schwarz-Christoffel method, in terms of preservation of velocities and execution time. Our method is as accurate as the Schwarz-Christoffel method, while being over 8 times faster. CONCLUSIONS Our mapping method can accurately preserve either the flow rate or the velocity field through the surface, and can cope with inconsistencies in motion and contour shape. SIGNIFICANCE The proposed method and its integration into the CRIMSON software enable a streamlined approach towards incorporating more patient-specific data in blood flow simulations.
Collapse
Affiliation(s)
- Alberto Gomez
- Department of Biomedical Engineering, King’s College London, UK
| | - Marija Marčan
- Department of Biomedical Engineering, King’s College London, UK
| | | | - Robert Wright
- Department of Biomedical Engineering, King’s College London, UK
| | - Pouya Youssefi
- Department of Cardiothoracic Surgery & Cardiology, St. George’s Hospital, London, UK
| | - Marjan Jahangiri
- Department of Cardiothoracic Surgery & Cardiology, St. George’s Hospital, London, UK
| | - C. Alberto Figueroa
- Department of Biomedical Engineering, King’s College London, UK, Departments of Surgery and Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
7
|
Del Gaudio C, Morbiducci U, Grigioni M. Time Dependent Non-Newtonian Numerical Study of the Flow Field in a Realistic Model of Aortic Arch. Int J Artif Organs 2018; 29:709-18. [PMID: 16874678 DOI: 10.1177/039139880602900711] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A three-dimensional time dependent numerical simulation was performed in a geometric model of aortic arch complete with a realistic aortic root and major branches originating from the arch, for a peak Reynolds number set at 2200 and Womersley number set at 20.4. The computational fluid dynamic analysis was aimed to provide spatial and temporal distribution of the shear stress all along the entire model together with the velocity patterns, related both to the non planar geometry of the aortic system here considered and to the pulsatility imposed on the numerical model to simulate physiologic conditions. A non-Newtonian evolving fluid was considered to account for the actual rheological nature of blood; a comparison on the incidence of wall shear stress, implementing a Newtonian fluid, was also made as reference. The spatial shear stress pattern, within the cardiac cycle, was shown to have higher values in correspondence to the inner wall of the aortic arch and the sites where the major vessels originated from the arch itself. The velocity patterns, on transversal sections of the aorta, resulted in highly skewed morphology. The resulting complex fluid dynamics, established in the aortic arch and in its branches, can be related to the possible endothelium response to mechanical stimuli, induced by wall shear stress, in the promotion of inflammatory events.
Collapse
Affiliation(s)
- C Del Gaudio
- Cardiovascular Bioengineering, Technology and Health Department, Istituto Superiore di Sanità, Rome, Italy
| | | | | |
Collapse
|
8
|
Slesnick TC. Role of Computational Modelling in Planning and Executing Interventional Procedures for Congenital Heart Disease. Can J Cardiol 2017; 33:1159-1170. [PMID: 28843327 DOI: 10.1016/j.cjca.2017.05.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 05/26/2017] [Accepted: 05/27/2017] [Indexed: 10/19/2022] Open
Abstract
Increasingly, computational modelling and numerical simulations are used to help plan complex surgical and interventional cardiovascular procedures in children and young adults with congenital heart disease. From its origins more than 30 years ago, surgical planning with analysis of flow hemodynamics and energy loss/efficiency has helped design and implement many modifications to existing techniques. On the basis of patient-specific medical imaging, surgical planning allows accurate model production that can then be manipulated in a virtual surgical environment, with the proposed solutions finally tested with advanced computational fluid dynamics to evaluate the results. Applications include a broad range of congenital heart disease, including patients with single-ventricle anatomy undergoing staged palliation, those with arch obstruction, with double outlet right ventricle, or with tetralogy of Fallot. In the present work, we focus on clinical applications of this exciting field. We describe the framework for these techniques, including brief descriptions of the engineering principles applied and the interaction between "benchtop" data with medical decision-making. We highlight some early insights learned from pioneers over the past few decades, including refinements in Fontan baffle geometries and configurations. Finally, we offer a glimpse into exciting advances that are presently being explored, including use of modelling for transcatheter interventions. In this era of personalized medicine, computational modelling and surgical planning allows patient-specific tailoring of interventions to optimize clinical outcomes.
Collapse
Affiliation(s)
- Timothy C Slesnick
- Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia.
| |
Collapse
|
9
|
van Bogerijen GHW, van Herwaarden JA, Conti M, Auricchio F, Rampoldi V, Trimarchi S, Moll FL. Importance of dynamic aortic evaluation in planning TEVAR. Ann Cardiothorac Surg 2014; 3:300-6. [PMID: 24967170 DOI: 10.3978/j.issn.2225-319x.2014.04.05] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 03/27/2014] [Indexed: 11/14/2022]
Abstract
Dynamic aortic evaluation in planning thoracic endovascular aortic repair (TEVAR) is important to provide optimal stent graft sizing. Static imaging protocols do not consider normal aortic dynamics and may lead to stent graft to aorta mismatch, causing stent graft related complications, such as type I endoleak and stent graft migration. Dynamic imaging can assist in accurate stent graft selection and sizing preoperatively, and evaluate stent graft performance during follow-up. To create new imaging technologies, integration of knowledge between diverse scientific fields is essential (i.e., engineering, informatics and medicine). Different dynamic imaging modalities, such as electrocardiographic-gated computed tomography angiography (ECG-gated CTA) and four-dimensional phase-contrast MRI (4D PC-MRI), are progressively investigated and implemented into clinical practice as important instruments in preoperative planning for TEVAR. In time, further application of dynamic imaging tools for preoperative screening and follow-up after TEVAR might lead to better outcomes for patients. The advances in dynamic imaging for evaluation of the thoracic aorta using new imaging modalities and their future perspectives are addressed in this manuscript.
Collapse
Affiliation(s)
- Guido H W van Bogerijen
- 1 Department of Vascular Surgery, University Medical Center Utrecht, The Netherlands ; 2 Thoracic Aortic Research Center, Policlinico San Donato IRCCS, University of Milan, Italy ; 3 Department of Civil Engineering and Architecture, Structural Mechanics Division, University of Pavia, Italy
| | - Joost A van Herwaarden
- 1 Department of Vascular Surgery, University Medical Center Utrecht, The Netherlands ; 2 Thoracic Aortic Research Center, Policlinico San Donato IRCCS, University of Milan, Italy ; 3 Department of Civil Engineering and Architecture, Structural Mechanics Division, University of Pavia, Italy
| | - Michele Conti
- 1 Department of Vascular Surgery, University Medical Center Utrecht, The Netherlands ; 2 Thoracic Aortic Research Center, Policlinico San Donato IRCCS, University of Milan, Italy ; 3 Department of Civil Engineering and Architecture, Structural Mechanics Division, University of Pavia, Italy
| | - Ferdinando Auricchio
- 1 Department of Vascular Surgery, University Medical Center Utrecht, The Netherlands ; 2 Thoracic Aortic Research Center, Policlinico San Donato IRCCS, University of Milan, Italy ; 3 Department of Civil Engineering and Architecture, Structural Mechanics Division, University of Pavia, Italy
| | - Vincenzo Rampoldi
- 1 Department of Vascular Surgery, University Medical Center Utrecht, The Netherlands ; 2 Thoracic Aortic Research Center, Policlinico San Donato IRCCS, University of Milan, Italy ; 3 Department of Civil Engineering and Architecture, Structural Mechanics Division, University of Pavia, Italy
| | - Santi Trimarchi
- 1 Department of Vascular Surgery, University Medical Center Utrecht, The Netherlands ; 2 Thoracic Aortic Research Center, Policlinico San Donato IRCCS, University of Milan, Italy ; 3 Department of Civil Engineering and Architecture, Structural Mechanics Division, University of Pavia, Italy
| | - Frans L Moll
- 1 Department of Vascular Surgery, University Medical Center Utrecht, The Netherlands ; 2 Thoracic Aortic Research Center, Policlinico San Donato IRCCS, University of Milan, Italy ; 3 Department of Civil Engineering and Architecture, Structural Mechanics Division, University of Pavia, Italy
| |
Collapse
|
10
|
Bürk J, Blanke P, Stankovic Z, Barker A, Russe M, Geiger J, Frydrychowicz A, Langer M, Markl M. Evaluation of 3D blood flow patterns and wall shear stress in the normal and dilated thoracic aorta using flow-sensitive 4D CMR. J Cardiovasc Magn Reson 2012; 14:84. [PMID: 23237187 PMCID: PMC3534249 DOI: 10.1186/1532-429x-14-84] [Citation(s) in RCA: 153] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Accepted: 11/28/2012] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The purpose of this study was to investigate 3D flow patterns and vessel wall parameters in patients with dilated ascending aorta, age-matched subjects, and healthy volunteers. METHODS Thoracic time-resolved 3D phase contrast CMR with 3-directional velocity encoding was applied to 33 patients with dilated ascending aorta (diameter≥40 mm, age=60±16 years), 15 age-matched normal controls (diameter≤37 mm, age=68±7.5 years) and 15 young healthy volunteers (diameter≤30 mm, age=23±2 years). 3D blood flow was visualized and flow patterns were graded regarding presence of supra-physiologic-helix and vortex flow using a semi-quantitative 3-point grading scale. Blood flow velocities, regional wall shear stress (WSS), and oscillatory shear index (OSI) were quantified. RESULTS Incidence and strength of supra-physiologic-helix and vortex flow in the ascending aorta (AAo) was significantly higher in patients with dilated AAo (16/33 and 31/33, grade 0.9±1.0 and 1.5±0.6) than in controls (2/15 and 7/15, grade 0.2±0.6 and 0.6±0.7, P<.05) or healthy volunteers (1/15 and 0/15, grade 0.1±0.3 P<.05). Greater strength of the ascending aortic helix and vortex flow were associated with significant differences in AAo diameters (P<.05). Peak systolic WSS in the ascending aorta and aortic arch was significantly lower in patients with dilated AAo (P<.0157-.0488). AAo diameter positively correlated to time to peak systolic velocities (r=0.30-0.53, P<.04), OSI (r=0.33-0.49, P<0.02) and inversely correlated to peak systolic WSS (r=0.32-0.40, P<.03). Peak systolic WSS was significantly lower in AAo aneurysms at the right and outer curvature within the AAo and proximal arch (P<.01-.05). CONCLUSIONS Increase in AAo diameter is significantly correlated with the presence and strength of supra-physiologic-helix and vortex formation in the AAo, as well with decrease in systolic WSS and increase in OSI.
Collapse
Affiliation(s)
- Jonas Bürk
- Department of Diagnostic Radiology, Medical Physics, University Hospital, Freiburg, Germany
| | - Philipp Blanke
- Department of Diagnostic Radiology, Medical Physics, University Hospital, Freiburg, Germany
| | - Zoran Stankovic
- Department of Diagnostic Radiology, Medical Physics, University Hospital, Freiburg, Germany
- Departments of Radiology and Biomedical Engineering, Northwestern University, Chicago, IL, USA
| | - Alex Barker
- Department of Diagnostic Radiology, Medical Physics, University Hospital, Freiburg, Germany
- Departments of Radiology and Biomedical Engineering, Northwestern University, Chicago, IL, USA
| | - Maximilian Russe
- Department of Diagnostic Radiology, Medical Physics, University Hospital, Freiburg, Germany
| | - Julia Geiger
- Department of Diagnostic Radiology, Medical Physics, University Hospital, Freiburg, Germany
| | - Alex Frydrychowicz
- Clinic of Radiology and Nuclear Medicine, University Hospital of Schleswig-Holstein, Campus, Lübeck, Germany
| | - Mathias Langer
- Department of Diagnostic Radiology, Medical Physics, University Hospital, Freiburg, Germany
| | - Michael Markl
- Department of Diagnostic Radiology, Medical Physics, University Hospital, Freiburg, Germany
- Departments of Radiology and Biomedical Engineering, Northwestern University, Chicago, IL, USA
| |
Collapse
|
11
|
Geiger J, Arnold R, Herzer L, Hirtler D, Stankovic Z, Russe M, Langer M, Markl M. Aortic wall shear stress in Marfan syndrome. Magn Reson Med 2012; 70:1137-44. [DOI: 10.1002/mrm.24562] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 09/18/2012] [Accepted: 10/24/2012] [Indexed: 11/07/2022]
Affiliation(s)
- Julia Geiger
- Department of Radiology, Medical Physics; University Medical Center; Freiburg Germany
| | - Raoul Arnold
- Department of Congenital Heart Disease and Pediatric Cardiology; University Medical Center; Heidelberg Germany
| | - Lena Herzer
- Department of Congenital Heart Disease and Pediatric Cardiology; University Medical Center; Freiburg Germany
| | - Daniel Hirtler
- Department of Congenital Heart Disease and Pediatric Cardiology; University Medical Center; Freiburg Germany
| | - Zoran Stankovic
- Department of Radiology, Medical Physics; University Medical Center; Freiburg Germany
| | - Max Russe
- Department of Radiology, Medical Physics; University Medical Center; Freiburg Germany
| | - Mathias Langer
- Department of Radiology, Medical Physics; University Medical Center; Freiburg Germany
| | - Michael Markl
- Department of Radiology and Biomedical Engineering; Northwestern University; Chicago Illinois USA
| |
Collapse
|
12
|
Kaufmann TA, Schmitz-Rode T, Steinseifer U. Implementation of Cerebral Autoregulation Into Computational Fluid Dynamics Studies of Cardiopulmonary Bypass. Artif Organs 2012; 36:754-8. [DOI: 10.1111/j.1525-1594.2012.01519.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
13
|
Lillie M, Armstrong T, Gérard S, Shadwick R, Gosline J. Contribution of elastin and collagen to the inflation response of the pig thoracic aorta: Assessing elastin's role in mechanical homeostasis. J Biomech 2012; 45:2133-41. [DOI: 10.1016/j.jbiomech.2012.05.034] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 04/05/2012] [Accepted: 05/24/2012] [Indexed: 11/26/2022]
|
14
|
Chang W, Loecher MW, Wu Y, Niemann DB, Ciske B, Aagaard-Kienitz B, Kecskemeti S, Johnson KM, Wieben O, Mistretta C, Turski P. Hemodynamic changes in patients with arteriovenous malformations assessed using high-resolution 3D radial phase-contrast MR angiography. AJNR Am J Neuroradiol 2012; 33:1565-72. [PMID: 22499844 DOI: 10.3174/ajnr.a3010] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Arteriovenous malformations have a high lifetime risk of hemorrhage; however, treatment carries a significant risk of morbidity and mortality, including permanent neurologic sequelae. WSS and other hemodynamic parameters are altered in patients with symptomatic AVMs, and analysis of hemodynamics may have value in stratifying patients into different risk groups. In this study, we examined hemodynamic data from patients with stable symptoms and those who presented with acute symptoms to identify trends which may help in risk stratification. MATERIALS AND METHODS Phase-contrast MRA using a radial readout (PC-VIPR) is a fast, high-resolution technique that can acquire whole-brain velocity-encoded angiograms with scan times of approximately 5 minutes. Ten patients with AVMs were scanned using PC-VIPR; velocity, area, flow, and WSS in vessels feeding the AVMs and normal contralateral vessels were calculated using velocity data from the phase-contrast acquisition. RESULTS Patients with an asymptomatic presentation or mild symptoms (n = 4) had no significant difference in WSS in feeding vessels compared with normal contralateral vessels, whereas patients presenting with hemorrhage, severe headaches/seizures, or focal neurologic deficits (n = 6) had significantly higher WSS in feeding vessels compared with contralateral vessels. CONCLUSIONS In this study, we demonstrate that estimates of WSS and other hemodynamic parameters can be obtained noninvasively in patients with AVMs in clinically useful imaging times. Variation in WSS between feeders and normal vessels appears to relate to the clinical presentation of the patient. Further analysis of hemodynamic changes may improve characterization and staging of AVM patients, when combined with existing risk factors.
Collapse
Affiliation(s)
- W Chang
- Department of Medical Physics, University of Wisconsin, Madison, WI 53705, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Pulsatile extracorporeal circulation during on-pump cardiac surgery enhances aortic wall shear stress. J Biomech 2012; 45:156-63. [DOI: 10.1016/j.jbiomech.2011.09.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 08/22/2011] [Accepted: 09/13/2011] [Indexed: 11/18/2022]
|
16
|
Torii R, Xu XY, El-Hamamsy I, Mohiaddin R, Yacoub MH. Computational biomechanics of the aortic root. ACTA ACUST UNITED AC 2011. [DOI: 10.5339/ahcsps.2011.16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Ryo Torii
- 1Qatar Cardiovascular Research Center, Doha,
Qatar
- 2Harefield Heart Science Centre, Imperial College London, Harefield,
UK
- 5Department of Chemical Engineering,
Imperial College London, London, UK
| | - Xiao Yun Xu
- 5Department of Chemical Engineering,
Imperial College London, London, UK
| | - Ismail El-Hamamsy
- 4Department of Cardiac Surgery, Montreal
Heart Institute, Montreal, Canada
| | - Raad Mohiaddin
- 3Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital and
Imperial College London, London, UK
| | - Magdi H. Yacoub
- 1Qatar Cardiovascular Research Center, Doha,
Qatar
- 2Harefield Heart Science Centre, Imperial College London, Harefield,
UK
| |
Collapse
|
17
|
Modin D, Renner J, Gårdhagen R, Ebbers T, Länne T, Karlsson M. Evaluation of aortic geometries created by magnetic resonance imaging data in healthy volunteers. Clin Physiol Funct Imaging 2011; 31:485-91. [PMID: 21981461 DOI: 10.1111/j.1475-097x.2011.01035.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
INTRODUCTION The development of atherosclerotic plaques has been associated with the patterns of wall shear stress (WSS). However, much is still uncertain with the methods used to calculate WSS. Correct vessel geometries are mandatory to get reliable estimations, and the purpose of this study was to evaluate an in vivo method for creating aortic 3D geometry in human based on data from magnetic resonance imaging (MRI) with ultrasound as reference. METHODS The aortas of ten healthy men, 23·4 ± 1·6 years of age, were examined with a 1·5 T MRI system using a 3D gadolinium-enhanced gradient-echo sequence. Three-dimensional geometries were created using manual segmentation of images. Lumen diameters (LD) were measured in the abdominal aorta (AA) and the thoracic aorta (TA) with non-invasive B-mode ultrasound as a reference. RESULTS The anteroposterior diameter of the AA was 13·6 ± 1·1 mm for the MRI and 13·8 ± 1·3 mm for the ultrasound (NS). Intraobserver variability (CV) for MRI and ultrasound was <0·92% and <0·40%, respectively. Interobserver variability for MRI and ultrasound was 0·96% and 0·56%, respectively. The diameter of the TA was 19·2 ± 1·4 mm for the MRI, and the intraobserver variability (CV) was <0·78% and interobserver variability (CV) was 0·92%. CONCLUSION Specific arterial geometries can be constructed with a high degree of accuracy using MRI. This indicates that the MRI geometries may be used to create realistic and correct geometries in the calculation of WSS in the aorta of human.
Collapse
Affiliation(s)
- Daniel Modin
- Department of Medicine and Health Sciences Department of Mechanical Engineering Center for Medical Image Science and Visualization (CMIV), Linköping University, Sweden
| | | | | | | | | | | |
Collapse
|
18
|
Olivieri LJ, de Zélicourt DA, Haggerty CM, Ratnayaka K, Cross RR, Yoganathan AP. Hemodynamic Modeling of Surgically Repaired Coarctation of the Aorta. Cardiovasc Eng Technol 2011; 2:288-295. [PMID: 22347895 DOI: 10.1007/s13239-011-0059-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE: Late morbidity of surgically repaired coarctation of the aorta includes early cardiovascular and cerebrovascular disease, shortened life expectancy, abnormal vasomodulator response, hypertension and exercise-induced hypertension in the absence of recurrent coarctation. Observational studies have linked patterns of arch remodeling (Gothic, Crenel, and Romanesque) to late morbidity, with Gothic arches having the highest incidence. We evaluated flow in native and surgically repaired aortic arches to correlate respective hemodynamic indices with incidence of late morbidity. METHODS: Three dimensional reconstructions of each remodeled arch were created from an anatomic stack of magnetic resonance (MR) images. A structured mesh core with a boundary layer was generated. Computational fluid dynamic (CFD) analysis was performed assuming peak flow conditions with a uniform velocity profile and unsteady turbulent flow. Wall shear stress (WSS), pressure and velocity data were extracted. RESULTS: The region of maximum WSS was located in the mid-transverse arch for the Crenel, Romanesque and Native arches. Peak WSS was located in the isthmus of the Gothic model. Variations in descending aorta flow patterns were also observed among the models. CONCLUSION: The location of peak WSS is a primary difference among the models tested, and may have clinical relevance. Specifically, the Gothic arch had a unique location of peak WSS with flow disorganization in the descending aorta. Our results suggest that varied patterns and locations of WSS resulting from abnormal arch remodeling may exhibit a primary effect on clinical vascular dysfunction.
Collapse
Affiliation(s)
- Laura J Olivieri
- Division of Cardiology, Children s National Medical Center, Washington, DC
| | | | | | | | | | | |
Collapse
|
19
|
Chang W, Landgraf B, Johnson KM, Kecskemeti S, Wu Y, Velikina J, Rowley H, Wieben O, Mistretta C, Turski P. Velocity measurements in the middle cerebral arteries of healthy volunteers using 3D radial phase-contrast HYPRFlow: comparison with transcranial Doppler sonography and 2D phase-contrast MR imaging. AJNR Am J Neuroradiol 2011; 32:54-9. [PMID: 20947642 DOI: 10.3174/ajnr.a2240] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE We have developed PC HYPRFlow, a comprehensive MRA technique that includes a whole-brain CE dynamic series followed by PC velocity-encoding, yielding a time series of high-resolution morphologic angiograms with associated velocity information. In this study, we present velocity data acquired by using the PC component of PC HYPRFlow (PC-VIPR). MATERIALS AND METHODS Ten healthy volunteers (6 women, 4 men) were scanned by using PC HYPRFlow and 2D-PC imaging, immediately followed by velocity measurements by using TCD. Velocity measurements were made in the M1 segments of the MCAs from the PC-VIPR, 2D-PC, and TCD examinations. RESULTS PC-VIPR showed approximately 30% lower mean velocity compared with TCD, consistent with other comparisons of TCD with PC-MRA. The correlation with TCD was r = 0.793, and the correlation of PC-VIPR with 2D-PC was r = 0.723. CONCLUSIONS PC-VIPR is a technique capable of acquiring high-resolution MRA of diagnostic quality with velocity data comparable with TCD and 2D-PC. The combination of velocity information and fast high-resolution whole-brain morphologic angiograms makes PC HYPRFlow an attractive alternative to current MRA methods.
Collapse
Affiliation(s)
- W Chang
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Ariff BB, Glor FP, Crowe L, Xu XY, Vennart W, Firmin DN, Thom SM, Hughes AD. Carotid Artery Hemodynamics: Observing Patient-specific Changes with Amlodipine and Lisinopril by Using MR Imaging Computation Fluid Dynamics. Radiology 2010; 257:662-9. [DOI: 10.1148/radiol.10100788] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
21
|
Harloff A, Nussbaumer A, Bauer S, Stalder AF, Frydrychowicz A, Weiller C, Hennig J, Markl M. In vivo assessment of wall shear stress in the atherosclerotic aorta using flow-sensitive 4D MRI. Magn Reson Med 2010; 63:1529-36. [PMID: 20512856 DOI: 10.1002/mrm.22383] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Andreas Harloff
- Department of Neurology, University Hospital Freiburg, Freiburg, Germany
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Wu Y, Chang W, Johnson KM, Velikina J, Rowley H, Mistretta C, Turski P. Fast whole-brain 4D contrast-enhanced MR angiography with velocity encoding using undersampled radial acquisition and highly constrained projection reconstruction: image-quality assessment in volunteer subjects. AJNR Am J Neuroradiol 2010; 32:E47-50. [PMID: 20223884 DOI: 10.3174/ajnr.a2048] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We report on the image quality obtained by using fast contrast-enhanced whole-brain 4D radial MRA with 0.75-second temporal resolution, isotropic submillimeter spatial resolution, and velocity encoding (HYPRFlow). Images generated by HYPR-LR by using the velocity-encoded data as the constraining image were of diagnostic quality. In addition, we demonstrate that measurements of shear stress within the middle cerebral artery can be derived from the high-resolution 3D velocity data.
Collapse
Affiliation(s)
- Y Wu
- Department of Medical Physics, University of Wisconsin, Madison, 53705, USA.
| | | | | | | | | | | | | |
Collapse
|
23
|
Frydrychowicz A, Stalder AF, Russe MF, Bock J, Bauer S, Harloff A, Berger A, Langer M, Hennig J, Markl M. Three-dimensional analysis of segmental wall shear stress in the aorta by flow-sensitive four-dimensional-MRI. J Magn Reson Imaging 2009; 30:77-84. [PMID: 19557849 DOI: 10.1002/jmri.21790] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To assess the distribution and regional differences of flow and vessel wall parameters such as wall shear stress (WSS) and oscillatory shear index (OSI) in the entire thoracic aorta. MATERIALS AND METHODS Thirty-one healthy volunteers (mean age = 23.7 +/- 3.3 years) were examined by flow-sensitive four-dimensional (4D)-MRI at 3T. For eight retrospectively positioned 2D analysis planes distributed along the thoracic aorta, flow parameters and vectorial WSS and OSI were assessed in 12 segments along the vascular circumference. RESULTS Mean absolute time-averaged WSS ranged between 0.25 +/- 0.04 N/m(2) and 0.33 +/- 0.07 N/m(2) and incorporated a substantial circumferential component (-0.05 +/- 0.04 to 0.07 +/- 0.02 N/m(2)). For each analysis plane, a segment with lowest absolute WSS and highest OSI was identified which differed significantly from mean values within the plane (P < 0.05). The distribution of atherogenic low WSS and high OSI closely resembled typical locations of atherosclerotic lesions at the inner aortic curvature and supraaortic branches. CONCLUSION The normal distribution of vectorial WSS and OSI in the entire thoracic aorta derived from flow-sensitive 4D-MRI data provides a reference constituting an important perquisite for the examination of patients with aortic disease. Marked regional differences in absolute WSS and OSI may help explaining why atherosclerotic lesions predominantly develop and progress at specific locations in the aorta.
Collapse
Affiliation(s)
- Alex Frydrychowicz
- Department of Diagnostic Radiology and Medical Physics, University Hospital Freiburg, Freiburg, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Pashaei A, Fatouraee N. An analytical phantom for the evaluation of medical flow imaging algorithms. Phys Med Biol 2009; 54:1791-821. [DOI: 10.1088/0031-9155/54/6/025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
25
|
Hoskins PR, Hardman D. Three-dimensional imaging and computational modelling for estimation of wall stresses in arteries. Br J Radiol 2009; 82 Spec No 1:S3-17. [DOI: 10.1259/bjr/96847348] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
|
26
|
Pekkan K, Dur O, Sundareswaran K, Kanter K, Fogel M, Yoganathan A, Ündar A. Neonatal Aortic Arch Hemodynamics and Perfusion During Cardiopulmonary Bypass. J Biomech Eng 2008; 130:061012. [DOI: 10.1115/1.2978988] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The objective of this study is to quantify the detailed three-dimensional (3D) pulsatile hemodynamics, mechanical loading, and perfusion characteristics of a patient-specific neonatal aortic arch during cardiopulmonary bypass (CPB). The 3D cardiac magnetic resonance imaging (MRI) reconstruction of a pediatric patient with a normal aortic arch is modified based on clinical literature to represent the neonatal morphology and flow conditions. The anatomical dimensions are verified from several literature sources. The CPB is created virtually in the computer by clamping the ascending aorta and inserting the computer-aided design model of the 10 Fr tapered generic cannula. Pulsatile (130 bpm) 3D blood flow velocities and pressures are computed using the commercial computational fluid dynamics (CFD) software. Second order accurate CFD settings are validated against particle image velocimetry experiments in an earlier study with a complex cardiovascular unsteady benchmark. CFD results in this manuscript are further compared with the in vivo physiological CPB pressure waveforms and demonstrated excellent agreement. Cannula inlet flow waveforms are measured from in vivo PC-MRI and 3 kg piglet neonatal animal model physiological experiments, distributed equally between the head-neck vessels and the descending aorta. Neonatal 3D aortic hemodynamics is also compared with that of the pediatric and fetal aortic stages. Detailed 3D flow fields, blood damage, wall shear stress (WSS), pressure drop, perfusion, and hemodynamic parameters describing the pulsatile energetics are calculated for both the physiological neonatal aorta and for the CPB aorta assembly. The primary flow structure is the high-speed canulla jet flow (∼3.0 m/s at peak flow), which eventually stagnates at the anterior aortic arch wall and low velocity flow in the cross-clamp pouch. These structures contributed to the reduced flow pulsatility (85%), increased WSS (50%), power loss (28%), and blood damage (288%), compared with normal neonatal aortic physiology. These drastic hemodynamic differences and associated intense biophysical loading of the pathological CPB configuration necessitate urgent bioengineering improvements—in hardware design, perfusion flow waveform, and configuration. This study serves to document the baseline condition, while the methodology presented can be utilized in preliminary CPB cannula design and in optimization studies reducing animal experiments. Coupled to a lumped-parameter model the 3D hemodynamic characteristics will aid the surgical decision making process of the perfusion strategies in complex congenital heart surgeries.
Collapse
Affiliation(s)
- Kerem Pekkan
- Department of Biomedical Engineering, Carnegie Mellon University, 2100 Doherty Hall, Pittsburgh, PA 15213-3890
| | - Onur Dur
- Department of Biomedical Engineering, Carnegie Mellon University, 2100 Doherty Hall, Pittsburgh, PA 15213-3890
| | - Kartik Sundareswaran
- Cardiovascular Fluid Mechanics Laboratory, Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 315 Ferst Drive, Atlanta, GA 30332-0535
| | - Kirk Kanter
- Pediatric Cardiothoracic Surgery, Emory University School of Medicine, 1440 Clifton Road, Atlanta, GA 30322
| | - Mark Fogel
- Children’s Hospital of Philadelphia, 34th Street, Civic Center Boulevard, Philadelphia, PA 19104
| | - Ajit Yoganathan
- Cardiovascular Fluid Mechanics Laboratory, Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 315 Ferst Drive, Atlanta, GA 30332-0535A
| | - Akif Ündar
- Department of Pediatrics, Surgery and Bioengineering, Penn State College of Medicine, Hershey, PA 17033
| |
Collapse
|
27
|
Canstein C, Cachot P, Faust A, Stalder AF, Bock J, Frydrychowicz A, Küffer J, Hennig J, Markl M. 3D MR flow analysis in realistic rapid-prototyping model systems of the thoracic aorta: comparison with in vivo data and computational fluid dynamics in identical vessel geometries. Magn Reson Med 2008; 59:535-46. [PMID: 18306406 DOI: 10.1002/mrm.21331] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The knowledge of local vascular anatomy and function in the human body is of high interest for the diagnosis and treatment of cardiovascular disease. A comprehensive analysis of the hemodynamics in the thoracic aorta is presented based on the integration of flow-sensitive 4D MRI with state-of-the-art rapid prototyping technology and computational fluid dynamics (CFD). Rapid prototyping was used to transform aortic geometries as measured by contrast-enhanced MR angiography into realistic vascular models with large anatomical coverage. Integration into a flow circuit with patient-specific pulsatile in-flow conditions and application of flow-sensitive 4D MRI permitted detailed analysis of local and global 3D flow dynamics in a realistic vascular geometry. Visualization of characteristic 3D flow patterns and quantitative comparisons of the in vitro experiments with in vivo data and CFD simulations in identical vascular geometries were performed to evaluate the accuracy of vascular model systems. The results indicate the potential of such patient-specific model systems for detailed experimental simulation of realistic vascular hemodynamics. Further studies are warranted to examine the influence of refined boundary conditions of the human circulatory system such as fluid-wall interaction and their effect on normal and pathological blood flow characteristics associated with vascular geometry.
Collapse
Affiliation(s)
- C Canstein
- Department of Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Pekkan K, Dasi LP, Nourparvar P, Yerneni S, Tobita K, Fogel MA, Keller B, Yoganathan A. In vitro hemodynamic investigation of the embryonic aortic arch at late gestation. J Biomech 2008; 41:1697-706. [PMID: 18466908 PMCID: PMC3805112 DOI: 10.1016/j.jbiomech.2008.03.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Revised: 03/10/2008] [Accepted: 03/11/2008] [Indexed: 10/22/2022]
Abstract
This study focuses on the dynamic flow through the fetal aortic arch driven by the concurrent action of right and left ventricles. We created a parametric pulsatile computational fluid dynamics (CFD) model of the fetal aortic junction with physiologic vessel geometries. To gain a better biophysical understanding, an in vitro experimental fetal flow loop for flow visualization was constructed for identical CFD conditions. CFD and in vitro experimental results were comparable. Swirling flow during the acceleration phase of the cardiac cycle and unidirectional flow following mid-deceleration phase were observed in pulmonary arteries (PA), head-neck vessels, and descending aorta. Right-to-left (oxygenated) blood flowed through the ductus arteriosus (DA) posterior relative to the antegrade left ventricular outflow tract (LVOT) stream and resembled jet flow. LVOT and right ventricular outflow tract flow mixing had not completed until approximately 3.5 descending aorta diameters downstream of the DA insertion into the aortic arch. Normal arch model flow patterns were then compared to flow patterns of four common congenital heart malformations that include aortic arch anomalies. Weak oscillatory reversing flow through the DA junction was observed only for the Tetralogy of Fallot configuration. PA and hypoplastic left heart syndrome configurations demonstrated complex, abnormal flow patterns in the PAs and head-neck vessels. Aortic coarctation resulted in large-scale recirculating flow in the aortic arch proximal to the DA. Intravascular flow patterns spatially correlated with abnormal vascular structures consistent with the paradigm that abnormal intravascular flow patterns associated with congenital heart disease influence vascular growth and function.
Collapse
Affiliation(s)
- Kerem Pekkan
- Department of Biomedical and Mechanical Engineering, Carnegie Mellon University, PA, USA.
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Effect of bundle branch block on cardiac output: a whole heart simulation study. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2008; 97:520-42. [PMID: 18384847 DOI: 10.1016/j.pbiomolbio.2008.02.022] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The heart is an electrically controlled fluid pump which operates by mechanical contraction. Whole heart modelling is a computationally daunting task which must incorporate several subsystems: mechanical, electrical, and fluidic. Numerous feedback mechanisms on many levels, and operating at different scales, exist to finely control behaviour. Understanding these interactions is necessary to understand heart operation, as well as pathologies and therapies. A review of the components in such a model is given. The authors then present a framework for their electro-mechano-fluidic whole heart model based on cable methods. The model incorporates atria and ventricles, and has functioning valves with papillary muscles. The effect of altered propagation due to left and right bundle branch block on cardiac output is examined using the cable-based model. Results are compared to clinically observed phenomena. Good agreement was obtained, but tighter coupling of mechanical and electrical events is needed to fully account for behaviour. Cable-based models offer an alternative to continuum models.
Collapse
|
30
|
Kolachalama VB, Bressloff NW, Nair PB. Mining data from hemodynamic simulations via Bayesian emulation. Biomed Eng Online 2007; 6:47. [PMID: 18078522 PMCID: PMC2231366 DOI: 10.1186/1475-925x-6-47] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2007] [Accepted: 12/13/2007] [Indexed: 12/15/2022] Open
Abstract
Background: Arterial geometry variability is inevitable both within and across individuals. To ensure realistic prediction of cardiovascular flows, there is a need for efficient numerical methods that can systematically account for geometric uncertainty. Methods and results: A statistical framework based on Bayesian Gaussian process modeling was proposed for mining data generated from computer simulations. The proposed approach was applied to analyze the influence of geometric parameters on hemodynamics in the human carotid artery bifurcation. A parametric model in conjunction with a design of computer experiments strategy was used for generating a set of observational data that contains the maximum wall shear stress values for a range of probable arterial geometries. The dataset was mined via a Bayesian Gaussian process emulator to estimate: (a) the influence of key parameters on the output via sensitivity analysis, (b) uncertainty in output as a function of uncertainty in input, and (c) which settings of the input parameters result in maximum and minimum values of the output. Finally, potential diagnostic indicators were proposed that can be used to aid the assessment of stroke risk for a given patient's geometry.
Collapse
Affiliation(s)
- Vijaya B Kolachalama
- Biomedical Engineering Center, Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA 02139, USA.
| | | | | |
Collapse
|
31
|
Yang GZ, Merrifield R, Masood S, Kilner PJ. Flow and myocardial interaction: an imaging perspective. Philos Trans R Soc Lond B Biol Sci 2007; 362:1329-41. [PMID: 17584731 PMCID: PMC2440399 DOI: 10.1098/rstb.2007.2119] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Heart failure due to coronary artery disease has considerable morbidity and poor prognosis. An understanding of the underlying mechanics governing myocardial contraction is a prerequisite for interpreting and predicting changes induced by heart disease. Gross changes in contractile behaviour of the myocardium are readily detected with existing techniques. For more subtle changes during early stages of cardiac dysfunction, however, a sensitive method for measuring, as well as a precise criterion for quantifying, normal and impaired myocardial function is required. The purpose of this paper is to outline the role of imaging, particularly cardiovascular magnetic resonance (CMR), for investigating the fundamental relationships between cardiac morphology, function and flow. CMR is emerging as an important clinical tool owing to its safety, versatility and the high-quality images it produces that allow accurate and reproducible quantification of cardiac structure and function. We demonstrate how morphological and functional assessment of the heart can be achieved by CMR and illustrate how blood flow imaging can be used to study flow and structure interaction, particularly for elucidating the underlying haemodynamic significance of directional changes and asymmetries of the cardiac looping. Future outlook on combining imaging with engineering approaches in subject-specific biomechanical simulation is also provided.
Collapse
Affiliation(s)
- Guang-Zhong Yang
- Royal Society/Wolfson Foundation Medical Image Computing Laboratory, Imperial College of Science, Technology and Medicine, London SW7 2BZ, UK.
| | | | | | | |
Collapse
|
32
|
Friedman MH, Himburg HA, LaMack JA. Statistical hemodynamics: a tool for evaluating the effect of fluid dynamic forces on vascular biology in vivo. J Biomech Eng 2007; 128:965-8. [PMID: 17154699 DOI: 10.1115/1.2354212] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND In vivo experimentation is the most realistic approach for exploring the vascular biological response to the hemodynamic stresses that are present in life. Post-mortem vascular casting has been used to define the in vivo geometry for hemodynamic simulation; however, this procedure damages or destroys the tissue and cells on which biological assays are to be performed. METHOD OF APPROACH Two statistical approaches, regional (RSH) and linear (LSH) statistical hemodynamics, are proposed and illustrated, in which flow simulations from one series of experiments are used to define a best estimate of the hemodynamic environment in a second series. As an illustration of the technique, RSH is used to compare the gene expression profiles of regions of the proximal external iliac arteries of swine exposed to different levels of time-average shear stress. RESULTS The results indicate that higher shears promote a more atheroprotective expression phenotype in porcine arterial endothelium. CONCLUSION Statistical hemodynamics provides a realistic estimate of the hemodynamic stress on vascular tissue that can be correlated against biological response.
Collapse
Affiliation(s)
- Morton H Friedman
- Duke University, Department of Biomedical Engineering, Box 90281, Durham, NC 27708, USA
| | | | | |
Collapse
|
33
|
Eichhorn JG, Fink C, Delorme S, Hagl S, Kauczor HU, Ulmer HE. Magnetic resonance blood flow measurements in the follow-up of pediatric patients with aortic coarctation – A re-evaluation. Int J Cardiol 2006; 113:291-8. [PMID: 16377005 DOI: 10.1016/j.ijcard.2005.11.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2005] [Revised: 10/25/2005] [Accepted: 11/04/2005] [Indexed: 11/28/2022]
Abstract
BACKGROUND Previous studies have suggested the feasibility of a non-invasive quantification of vascular trans-stenotic pressure gradients (DeltaP) by phase-contrast MR imaging (PC-MRI). Our purpose was to assess the value of MRI estimated pressure gradients as a screening tool for assessing hemodynamically significant (re-)coarctation of the aorta (CoA) in pediatric patients. METHODS Forty-three patients (median age (range), 16 (5-25) years) with CoA (38 postoperative and 5 native) and clinically suspected hemodynamically significant stenosis underwent quantitative and semi-quantitative PC-MRI blood flow measurements and 3D MR-angiography, Doppler ultrasound (US) and conventional catheter angiography (CCA, n=20). Estimated DeltaP for each modality was correlated with percent stenosis. RESULTS The percent stenosis correlated only moderately with DeltaP(MRI) (r=0.55, p<0.001) and DeltaP(CCA) (r=0.48, p<0.001). Only moderate correlations were observed between DeltaP(MRI) vs. DeltaP(CCA) (r=0.54, p=0.02) and vs. DeltaP(US) (r=0.40, p=0.01). In contrast, semi-quantitative analysis of PC-MRI flow profiles predicted with good sensitivity (88%) and specificity (88%) who would be operated on. Thirteen patients met hemodynamic and percent stenosis criteria by CCA for surgical intervention. CONCLUSION Measured pressure gradients using PC-MRI should be used cautiously when assessing patients for recoarctation of the aorta. The analysis of blood flow profiles by PC-MRI might be a promising alternative in assessing the hemodynamic significance of CoA.
Collapse
Affiliation(s)
- Joachim G Eichhorn
- Department of Paediatric Cardiology, University Children's Hospital, Im Neuenheimer Feld 153, 69120 Heidelberg, Germany.
| | | | | | | | | | | |
Collapse
|
34
|
Wood NB, Zhao SZ, Zambanini A, Jackson M, Gedroyc W, Thom SA, Hughes AD, Xu XY. Curvature and tortuosity of the superficial femoral artery: a possible risk factor for peripheral arterial disease. J Appl Physiol (1985) 2006; 101:1412-8. [PMID: 16825527 DOI: 10.1152/japplphysiol.00051.2006] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Atherosclerosis in the superficial femoral artery (SFA) resulting in peripheral arterial disease is more common in men than women and shows a predilection for the region of the adductor canal. Blood flow patterns are related to development of atherosclerosis, and we investigated if curvature and tortuosity of the femoral artery differed between young men and women and if differences resulted in adverse flow patterns. Magnetic resonance imaging (MRI) and computational fluid dynamics (CFD) were combined in 18 young adult volunteers (9 men) to assess the relationship of flow features to likely sites of future atherosclerosis formation. Subjects underwent MRI of the right SFA, three-dimensional vascular geometry was reconstructed, and measures of tortuosity and curvature were calculated. Tortuosity and curvature were significantly greater for men than women, and this was related to increased body surface area, body mass index, or weight in men. In both sexes, “tortuosity” increased from the midthigh to the popliteal fossa. The greatest curvature was found within the distal quarter of the SFA. CFD modeling was undertaken on MRI-based reconstructions of the SFA. Wall shear stresses (WSS) were extracted from the computations. WSS showed greater spatial variation in the men than in the women, and the men exhibited lower mean WSS. These data indicate that sex differences related to body size and anatomical course of the femoral artery may contribute to the enhanced risk of focal atherosclerosis in the adductor canal.
Collapse
Affiliation(s)
- N B Wood
- Chemical Engineering, International Centre for Circulatory Health, Imperial College London, London, SW7 2AZ, UK
| | | | | | | | | | | | | | | |
Collapse
|
35
|
YAMAGUCHI T, ISHIKAWA T, TSUBOTA KI, IMAI Y, NAKAMURA M, FUKUI T. Computational Blood Flow Analysis -New Trends and Methods. ACTA ACUST UNITED AC 2006. [DOI: 10.1299/jbse.1.29] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Takami YAMAGUCHI
- Dept. of Bioengineering and Robotics, Grad. Sch. Eng., Tohoku University
| | - Takuji ISHIKAWA
- Dept. of Bioengineering and Robotics, Grad. Sch. Eng., Tohoku University
| | - Ken-ichi TSUBOTA
- Dept. of Bioengineering and Robotics, Grad. Sch. Eng., Tohoku University
| | - Yohsuke IMAI
- Dept. of Bioengineering and Robotics, Grad. Sch. Eng., Tohoku University
| | - Masanori NAKAMURA
- Dept. of Bioengineering and Robotics, Grad. Sch. Eng., Tohoku University
| | - Tomohiro FUKUI
- Dept. of Bioengineering and Robotics, Grad. Sch. Eng., Tohoku University
| |
Collapse
|
36
|
Grigioni M, Daniele C, Morbiducci U, Del Gaudio C, D'Avenio G, Balducci A, Barbaro V. A mathematical description of blood spiral flow in vessels: application to a numerical study of flow in arterial bending. J Biomech 2005; 38:1375-86. [PMID: 15922748 DOI: 10.1016/j.jbiomech.2004.06.028] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2004] [Accepted: 06/30/2004] [Indexed: 10/26/2022]
Abstract
Local arterial haemodynamics has been associated with the pathophysiology of several cardiovascular diseases. The stable spiral blood-flows that were observed in vivo in several vessels, may play a dual role in vascular haemodynamics, beneficial since it induces stability, reducing turbulence in the arterial tree, and accounts for normal organ perfusion, but detrimental in view of the imparted tangential velocities that are involved in plaque formation and development. Being a spiral flow considered representative of the local blood dynamics in certain vessels, a method is proposed to quantify the spiral structure of blood flow. The proposed function, computed along a cluster of particle trajectories, has been tested for the quantitative determination of the spiral blood flow in a three-dimensional, s-shaped femoral artery numerical model in which three degrees of stenosis were simulated in a site prone to atherosclerotic development. Our results confirm the efficacy of the Lagrangian analysis as a tool for vascular blood dynamics investigation. The proposed method quantified spiral motion, and revealed the progression in the degree of stenosis, in the presented case study. In the future, it could be used as a synthetic tool to approach specific clinical complications.
Collapse
Affiliation(s)
- Mauro Grigioni
- Laboratory of Biomedical Engineering, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy.
| | | | | | | | | | | | | |
Collapse
|
37
|
Shojima M, Oshima M, Takagi K, Torii R, Hayakawa M, Katada K, Morita A, Kirino T. Magnitude and Role of Wall Shear Stress on Cerebral Aneurysm. Stroke 2004; 35:2500-5. [PMID: 15514200 DOI: 10.1161/01.str.0000144648.89172.0f] [Citation(s) in RCA: 465] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Wall shear stress (WSS) is one of the main pathogenic factors in the development of saccular cerebral aneurysms. The magnitude and distribution of the WSS in and around human middle cerebral artery (MCA) aneurysms were analyzed using the method of computed fluid dynamics (CFD). METHODS Twenty mathematical models of MCA vessels with aneurysms were created by 3-dimensional computed tomographic angiography. CFD calculations were performed by using our original finite-element solver with the assumption of Newtonian fluid property for blood and the rigid wall property for the vessel and the aneurysm. RESULTS The maximum WSS in the calculated region tended to occur near the neck of the aneurysm, not in its tip or bleb. The magnitude of the maximum WSS was 14.39+/-6.21 N/m2, which was 4-times higher than the average WSS in the vessel region (3.64+/-1.25 N/m2). The average WSS of the aneurysm region (1.64+/-1.16 N/m2) was significantly lower than that of the vessel region (P<0.05). The WSSs at the tip of ruptured aneurysms were markedly low. CONCLUSIONS These results suggest that in contrast to the pathogenic effect of a high WSS in the initiating phase, a low WSS may facilitate the growing phase and may trigger the rupture of a cerebral aneurysm by causing degenerative changes in the aneurysm wall. The WSS of the aneurysm region may be of some help for the prediction of rupture.
Collapse
Affiliation(s)
- Masaaki Shojima
- Department of Neurosurgery, Faculty of Medicine, University of Tokyo, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Tateshima S, Grinstead J, Sinha S, Nien YL, Murayama Y, Villablanca JP, Tanishita K, Viñuela F. Intraaneurysmal flow visualization by using phase-contrast magnetic resonance imaging: feasibility study based on a geometrically realistic in vitro aneurysm model. J Neurosurg 2004; 100:1041-8. [PMID: 15200119 DOI: 10.3171/jns.2004.100.6.1041] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The aim of this study was to evaluate the feasibility of complex intraaneurysmal flow visualization with the currently available phase-contrast magnetic resonance (MR) imaging modality. METHODS A geometrically realistic in vitro aneurysm model, in which detailed flow velocity analysis had already been conducted using laser Doppler velocimetry was used for this in vitro hemodynamic simulation, so that the results of phase-contrast velocity measurements could be compared with the previous reliable results. On a 1.5-tesla unit, three orthogonal components of velocity were obtained using a standard two-dimensional fast low-angle shot flow quantification sequence. Three-dimensional (3D) intraaneurysmal flow structures recorded during one cardiac cycle were depicted in one midsagittal and three axial cross-sectional planes with the aid of gray scale phase-contrast velocity maps. Isovelocity contour maps and secondary flow vectors were also created based on the phase-contrast velocity maps by using MATLAB software. The isovelocity contours in those three axial sections could demonstrate the shapes of inward and outward flow areas and their alternation over one cardiac cycle. The secondary flow vectors demonstrated twin vortices within the outward flow area adjacent to the boundary layer of inward and outward flow in all axial planes. CONCLUSIONS The phase-contrast MR imaging method was able to depict the complex 3D intraaneurysmal flow structures in the in vitro aneurysm model. Detailed 3D intraaneurysmal flow information will be obtainable in vivo after improvements are made in spatial resolution, which is expected in the near future. The capability to visualize intraaneurysmal flow structures directly with the use of noninvasive MR imaging technology will have a positive impact on future clinical practice.
Collapse
Affiliation(s)
- Satoshi Tateshima
- Department of Radiological Sciences, University of California at Los Angeles Medical Center, Los Angeles, California 90095-1721, USA.
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Markl M, Draney MT, Hope MD, Levin JM, Chan FP, Alley MT, Pelc NJ, Herfkens RJ. Time-Resolved 3-Dimensional Velocity Mapping in the Thoracic Aorta. J Comput Assist Tomogr 2004; 28:459-68. [PMID: 15232376 DOI: 10.1097/00004728-200407000-00005] [Citation(s) in RCA: 166] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
OBJECTIVE An analysis of thoracic aortic blood flow in normal subjects and patients with aortic pathologic findings is presented. Various visualization tools were used to analyze blood flow patterns within a single 3-component velocity volumetric acquisition of the entire thoracic aorta METHODS Time-resolved, 3-dimensional phase-contrast magnetic resonance imaging (3D CINE PC MRI) was employed to obtain complete spatial and temporal coverage of the entire thoracic aorta combined with spatially registered 3-directional pulsatile blood flow velocities. Three-dimensional visualization tools, including time-resolved velocity vector fields reformatted to arbitrary 2-dimensional cut planes, 3D streamlines, and time-resolved 3D particle traces, were applied in a study with 10 normal volunteers. Results from 4 patient examinations with similar scan prescriptions to those of the volunteer scans are presented to illustrate flow features associated with common pathologic findings in the thoracic aorta. RESULTS Previously reported blood flow patterns in the thoracic aorta, including right-handed helical outflow, late systolic retrograde flow, and accelerated passage through the aortic valve plane, were visualized in all volunteers. The effects of thoracic aortic disease on spatial and temporal blood flow patterns are illustrated in clinical cases, including ascending aortic aneurysms, aortic regurgitation, and aortic dissection. CONCLUSION Time-resolved 3D velocity mapping was successfully applied in a study of 10 healthy volunteers and 4 patients with documented aortic pathologic findings and has proven to be a reliable tool for analysis and visualization of normal characteristic as well as pathologic flow features within the entire thoracic aorta.
Collapse
Affiliation(s)
- Michael Markl
- Department of Radiology, Stanford University, Stanford, CA 94304, USA.
| | | | | | | | | | | | | | | |
Collapse
|
40
|
Houston JG, Gandy SJ, Sheppard DG, Dick JB, Belch JJF, Stonebridge PA. Two-dimensional flow quantitative MRI of aortic arch blood flow patterns: Effect of age, sex, and presence of carotid atheromatous disease on prevalence of spiral blood flow. J Magn Reson Imaging 2003; 18:169-74. [PMID: 12884328 DOI: 10.1002/jmri.10341] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To determine the effect of age, sex, and presence of carotid atheromatous disease on the presence of aortic spiral blood flow pattern using two-dimensional flow quantitative magnetic resonance imaging (MRI). MATERIALS AND METHODS Sixty subjects (37 women, 23 men) were examined. Prospective phase contrast flow quantitative MRI (1.5 T, Siemens Symphony) sequences in the plane of the aortic arch, and three-dimensional contrast-enhanced MR angiography of the vessels from the aortic arch to the circle of Willis, were performed. Flow quantitative analysis, using circular regions of interest, in the root, apex, and descending aortic arch to determine the presence of a spiral blood flow pattern was undertaken. The results were correlated with the subjects age, sex, and presence of significant carotid arterial disease. RESULTS A spiral blood flow pattern was seen during diastole in 43 of 50 (86%), 42 of 48 (88%), and in 26 of 28 (93%) subjects in the root, apex, and descending aortic arch, respectively. Spiral flow was seen during systole in 14 of 35 (40%), 20 of 47 (42%), and 11 of 31 (35%) subjects in the root, apex, and descending aortic arch, respectively. There was no clear effect of age or sex on the presence of spiral flow. Carotid disease was associated with a significant reduction in the prevalence of systolic spiral flow from 51%-19% subjects (P < 0.05). CONCLUSION Spiral flow pattern can be seen in the arch of the aorta in clinical practice using flow quantitative MRI. The prevalence of spiral flow pattern does not appear affected by subject age or sex. Carotid atheromatous disease is associated with a reduction in prevalence of systolic spiral flow pattern in the aortic arch.
Collapse
Affiliation(s)
- J Graeme Houston
- Department of Clinical Radiology, Ninewells Hospital and Medical School, Tayside University Hospitals NHS Trust, Dundee, Scotland, UK.
| | | | | | | | | | | |
Collapse
|
41
|
Wentzel JJ, Aguiar SH, Fayad ZA. Vascular MRI in the diagnosis and therapy of the high risk atherosclerotic plaque. J Interv Cardiol 2003; 16:129-42. [PMID: 12768916 DOI: 10.1046/j.1540-8183.2003.08024.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Disruption of a high risk plaque is known as the primary cause of cardiovascular events. Characterization of arterial wall components has become an essential adjunct in the identification of patients with plaques prone to rupture. Magnetic Resonance Imaging (MRI) has been revealed as one of the noninvasive tools possibly capable of identifying and characterizing high risk atherosclerotic plaque. MRI may facilitate diagnosis, and guide and serially monitor interventional and pharmacological treatment of atherosclerotic disease. In addition, it permits the simultaneous assessment of the anatomy, morphology, and hemodynamics for the study of flow-induced atherogenesis. It possibly will identify asymptomatic patients with subclinical atherosclerosis. This has potential significance for the improvement of strategies in primary and secondary prevention.
Collapse
Affiliation(s)
- Jolanda J Wentzel
- Zena and Michael A. Wiener Cardiovascular Institute, Imaging Science Laboratories, Mount Sinai School of Medicine, New York, NY, USA
| | | | | |
Collapse
|
42
|
Glor FP, Westenberg JJM, Vierendeels J, Danilouchkine M, Verdonck P. Validation of the coupling of magnetic resonance imaging velocity measurements with computational fluid dynamics in a U bend. Artif Organs 2002; 26:622-35. [PMID: 12081521 DOI: 10.1046/j.1525-1594.2002.07085.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Magnetic resonance imaging (MRI) can be used in vivo in combination with computational fluid dynamics (CFD) to derive velocity profiles in space and time and accordingly, pressure drop and wall shear stress distribution in natural or artificial vessel segments. These hemodynamic data are difficult or impossible to acquire directly in vivo. Therefore, research has been performed combining MRI and CFD for flow simulations in flow phantoms, such as bends or anastomoses, and even in human vessels such as the aorta, the carotid, and the abdominal bifurcation. There is, however, no unanimity concerning the use of MRI velocity measurements as input for the inflow boundary condition of a CFD simulation. In this study, different input possibilities for the inflow boundary conditions are compared. MRI measurements of steady and pulsatile flow were performed on a U bend phantom, representing the aorta geometry. PAMFLOW (ESI Software, Krimpen aan den Ussel, The Netherlands), an industrial CFD software package, was used to solve the Navier-Stokes equations for incompressible flow. Three main parameters were found to influence the choice of an inflow boundary condition type. First, the flow rate through a vessel should be exact, since it proves to be a determining factor for the accuracy of the velocity profile. The other decisive parameters are the physiology of the flow profile and the required computer processing unit time. Our comparative study indicates that the best way to handle an inflow boundary condition is to use the velocities measured by MRI at the inflow plane as being fixed velocities. However, before using these MRI velocity data, they first should be corrected for the partial volume effect by filtering and second scaled in order to obtain the correct flow rate. This implies that a reliable flow rate measurement absolutely is needed for CFD calculations based on MRI velocity measurements.
Collapse
Affiliation(s)
- F P Glor
- Hydraulics Laboratory, Institute of Biomedical Technology, Ghent University, Ghent, Belgium
| | | | | | | | | |
Collapse
|
43
|
Current awareness in NMR in biomedicine. NMR IN BIOMEDICINE 2002; 15:251-262. [PMID: 11968141 DOI: 10.1002/nbm.748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|