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Identification of intra-individual variation in intracranial arterial flow by MRI and the effect on computed hemodynamic descriptors. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2021; 34:659-666. [PMID: 33839985 DOI: 10.1007/s10334-021-00917-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 02/13/2021] [Accepted: 02/16/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVES To determine the intra-individual flow variation in serially acquired studies, and the influence of this variation on subsequent hemodynamic simulations using the inlet flow as a boundary condition. Author: Kindly check and confirm whether the corresponding authors are correctly identified.Confirmed. MATERIALS AND METHODS This prospective study included 51 patients (37 females and 14 males) with unruptured intracranial aneurysms who have received more than three times follow-up of 2D phase-contrast MR. The flow and velocity parameters were extracted to calculate the reproducibility and variation. Patient-specific computational fluid dynamics simulations were performed using the measured flows. RESULTS Intraclass correlation coefficients for mean and maximum velocity and flow parameters ranged from 0.77 to 0.90. A 10% CV of mean flow was identified. Variations of 10% in inlet flow resulted in hemodynamic changes including 41.41% of peak systolic wall shear stress; 39.13% of end-diastolic wall shear stress; 2.79% of low shear area at peak systole; 2.12% of low shear area at end diastole: 47.57% of time-averaged wall shear stress; and 0.17% of oscillatory shear index. CONCLUSION This study identified 10% of intra-individual mean flow variation on phase-contrast MR. Intra-individual flow variation resulted in a non-negligible variation in wall shear stress, but relatively small variation in low shear area in hemodynamic calculations.
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2
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Flow-splitting-based computation of outlet boundary conditions for improved cerebrovascular simulation in multiple intracranial aneurysms. Int J Comput Assist Radiol Surg 2019; 14:1805-1813. [PMID: 31363984 DOI: 10.1007/s11548-019-02036-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 07/18/2019] [Indexed: 01/20/2023]
Abstract
PURPOSE Image-based hemodynamic simulations have great potential for precise blood flow predictions in intracranial aneurysms. Due to model assumptions and simplifications with respect to boundary conditions, clinical acceptance remains limited. METHODS Within this study, we analyzed the influence of outflow-splitting approaches on multiple aneurysm studies and present a new outflow-splitting approach that takes the precise morphological vessel cross sections into account. We provide a detailed comparison of five outflow strategies considering eight intracranial aneurysms: zero-pressure configuration (1), a flow splitting inspired by Murray's law with a square (2) and a cubic (3) vessel diameter, a flow splitting incorporating vessel bifurcations based on circular vessel cross sections (4) and our novel flow splitting including vessel bifurcations and anatomical vessel cross sections (5). Other boundary conditions remain constant. For each simulation and each aneurysm, we conducted an evaluation based on common hemodynamic parameters, e.g., normalized wall shear stress and inflow concentration index. RESULTS The comparison of five outflow strategies for image-based simulations shows a large variability regarding the parameters of interest. Qualitatively, our strategy based on anatomical cross sections yields a more uniform flow rate distribution with increased aneurysm inflow rates. The commonly used zero-pressure approach shows the largest variations, especially for more distal aneurysms. A rank ordering of multiple aneurysms in one patient might still be possible, since the ordering appeared to be independent of the outflow strategy. CONCLUSIONS The results reveal that outlet boundary conditions have a crucial impact on image-based blood flow simulations, especially for multiple aneurysm studies. We could confirm the advantages of the more complex outflow-splitting model (4) including an incremental improvement (5) compared to strategies (1), (2) and (3) for this application scenario. Furthermore, we discourage from using zero-pressure configurations that lack a physiological basis.
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Watanabe T, Isoda H, Fukuyama A, Takahashi M, Amano T, Takehara Y, Oishi N, Kawate M, Terada M, Kosugi T, Komori Y, Fukuma Y, Alley M. Accuracy of the Flow Velocity and Three-directional Velocity Profile Measured with Three-dimensional Cine Phase-contrast MR Imaging: Verification on Scanners from Different Manufacturers. Magn Reson Med Sci 2019; 18:265-271. [PMID: 30828045 PMCID: PMC6883082 DOI: 10.2463/mrms.mp.2018-0063] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Purpose: The accuracy of flow velocity and three-directional velocity components are important for the precise visualization of hemodynamics by 3D cine phase-contrast MRI (3D cine PC MRI, also referred to as 4D-flow). The aim of this study was to verify the accuracy of these measurements of prototype or commercially available 3D cine PC MRI obtained by three different manufactures’ MR scanners. Methods: The verification of the accuracy of flow velocity in 3D cine PC MRI was performed by circulating blood mimicking fluid through a straight-tube phantom in a slanting position, such that the three-directional velocity components were simultaneously measurable, using three 3T MR scanners from different manufacturers. The data obtained were processed by phase correction, and the velocity and three-directional velocity components in the center of the tube on the central cross section of a slab were calculated. The velocity profile in each three directions and the composite velocity profiles were compared with the calculated reference values, using the Hagen–Poiseuille equation. In addition, velocity profiles and the spatially time-averaged velocity perpendicular to the tube were compared with the theoretical values and measured values by a flowmeter, respectively. Results: An underestimation of the maximum velocity in the center of the tube and an overestimation of the velocity near the tube wall due to partial volume effects were observed in all three scanners. A roughening and flattening of profiles in the center of the tube were observed in one scanner, due, presumably, to the low signal-to-noise ratio. However, the spatially time-averaged velocities corresponded well with the measured values by the flowmeter in all three scanners. Conclusion: In this study, we have demonstrated that the accuracy of flow velocity and three-directional velocity components in 3D cine PC MRI was satisfactory in all three MR scanners.
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Affiliation(s)
- Tomoya Watanabe
- Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine
| | - Haruo Isoda
- Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine.,Brain & Mind Research Center, Nagoya University
| | - Atushi Fukuyama
- Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine
| | | | - Tomoyasu Amano
- Department of Diagnostic Radiological Technology, Seirei Mikatahara General Hospital
| | - Yasuo Takehara
- Department of Fundamental Development for Advanced Low Invasive Diagnostic Imaging, Nagoya University, Graduate School of Medicine.,Department of Radiology, Hamamatsu University Hospital
| | - Naoki Oishi
- Department of Radiology, Hamamatsu University Hospital
| | | | - Masaki Terada
- Department of Diagnostic Radiological Technology, Iwata City Hospital
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Ii S, Adib MAHM, Watanabe Y, Wada S. Physically consistent data assimilation method based on feedback control for patient-specific blood flow analysis. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2018; 34:e2910. [PMID: 28618187 DOI: 10.1002/cnm.2910] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 06/12/2017] [Accepted: 06/12/2017] [Indexed: 06/07/2023]
Abstract
This paper presents a novel data assimilation method for patient-specific blood flow analysis based on feedback control theory called the physically consistent feedback control-based data assimilation (PFC-DA) method. In the PFC-DA method, the signal, which is the residual error term of the velocity when comparing the numerical and reference measurement data, is cast as a source term in a Poisson equation for the scalar potential field that induces flow in a closed system. The pressure values at the inlet and outlet boundaries are recursively calculated by this scalar potential field. Hence, the flow field is physically consistent because it is driven by the calculated inlet and outlet pressures, without any artificial body forces. As compared with existing variational approaches, although this PFC-DA method does not guarantee the optimal solution, only one additional Poisson equation for the scalar potential field is required, providing a remarkable improvement for such a small additional computational cost at every iteration. Through numerical examples for 2D and 3D exact flow fields, with both noise-free and noisy reference data as well as a blood flow analysis on a cerebral aneurysm using actual patient data, the robustness and accuracy of this approach is shown. Moreover, the feasibility of a patient-specific practical blood flow analysis is demonstrated.
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Affiliation(s)
- Satoshi Ii
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531, Japan
| | - Mohd Azrul Hisham Mohd Adib
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531, Japan
| | - Yoshiyuki Watanabe
- Graduate School of Medicine, Osaka University, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Shigeo Wada
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531, Japan
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5
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Tiago J, Guerra T, Sequeira A. A velocity tracking approach for the data assimilation problem in blood flow simulations. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2017; 33:e2856. [PMID: 27883273 DOI: 10.1002/cnm.2856] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 11/20/2016] [Indexed: 06/06/2023]
Abstract
Several advances have been made in data assimilation techniques applied to blood flow modeling. Typically, idealized boundary conditions, only verified in straight parts of the vessel, are assumed. We present a general approach, on the basis of a Dirichlet boundary control problem, that may potentially be used in different parts of the arterial system. The relevance of this method appears when computational reconstructions of the 3D domains, prone to be considered sufficiently extended, are either not possible, or desirable, because of computational costs. On the basis of taking a fully unknown velocity profile as the control, the approach uses a discretize then optimize methodology to solve the control problem numerically. The methodology is applied to a realistic 3D geometry representing a brain aneurysm. The results show that this data assimilation approach may be preferable to a pressure control strategy and that it can significantly improve the accuracy associated to typical solutions obtained using idealized velocity profiles.
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Affiliation(s)
- J Tiago
- Department of Mathematics and CEMAT, IST, ULisboa, Portugal
| | - T Guerra
- ESTBarreiro, Instituto Politécnico de Setúbal, Portugal
| | - A Sequeira
- Department of Mathematics and CEMAT, IST, ULisboa, Portugal
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6
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Lawley CM, Broadhouse KM, Callaghan FM, Winlaw DS, Figtree GA, Grieve SM. 4D flow magnetic resonance imaging: role in pediatric congenital heart disease. Asian Cardiovasc Thorac Ann 2017; 26:28-37. [PMID: 28185475 DOI: 10.1177/0218492317694248] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Imaging-based evaluation of cardiac structure and function remains paramount in the diagnosis and monitoring of congenital heart disease in childhood. Accurate measurements of intra- and extracardiac hemodynamics are required to inform decision making, allowing planned timing of interventions prior to deterioration of cardiac function. Four-dimensional flow magnetic resonance imaging is a nonionizing noninvasive technology that allows accurate and reproducible delineation of blood flow at any anatomical location within the imaging volume of interest, and also permits derivation of physiological parameters such as kinetic energy and wall shear stress. Four-dimensional flow is the focus of a great deal of attention in adult medicine, however, the translation of this imaging technique into the pediatric population has been limited to date. A more broad-scaled application of 4-dimensional flow in pediatric congenital heart disease stands to increase our fundamental understanding of the cause and significance of abnormal blood flow patterns, may improve risk stratification, and inform the design and use of surgical and percutaneous correction techniques. This paper seeks to outline the application of 4-dimensional flow in the assessment and management of the pediatric population affected by congenital heart disease.
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Affiliation(s)
- Claire M Lawley
- 1 Sydney Translational Imaging Laboratory, Sydney Heart Research Institute, Charles Perkins Centre, University of Sydney, Sydney, Australia.,2 North Shore Heart Research Group, Kolling Institute of Medical Research, Sydney Medical School Northern, University of Sydney, Sydney, Australia.,3 Clinical Population Perinatal Health Research, Kolling Institute, University of Sydney, Sydney, Australia
| | - Kathryn M Broadhouse
- 1 Sydney Translational Imaging Laboratory, Sydney Heart Research Institute, Charles Perkins Centre, University of Sydney, Sydney, Australia
| | - Fraser M Callaghan
- 1 Sydney Translational Imaging Laboratory, Sydney Heart Research Institute, Charles Perkins Centre, University of Sydney, Sydney, Australia
| | - David S Winlaw
- 4 Heart Centre for Children & University of Sydney, The Children's Hospital at Westmead, Sydney, Australia
| | - Gemma A Figtree
- 1 Sydney Translational Imaging Laboratory, Sydney Heart Research Institute, Charles Perkins Centre, University of Sydney, Sydney, Australia.,2 North Shore Heart Research Group, Kolling Institute of Medical Research, Sydney Medical School Northern, University of Sydney, Sydney, Australia
| | - Stuart M Grieve
- 1 Sydney Translational Imaging Laboratory, Sydney Heart Research Institute, Charles Perkins Centre, University of Sydney, Sydney, Australia.,2 North Shore Heart Research Group, Kolling Institute of Medical Research, Sydney Medical School Northern, University of Sydney, Sydney, Australia.,5 Department of Radiology, Royal Prince Alfred Hospital, Sydney, Australia
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7
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Liu X, Hou F, Qin H, Hao A. Robust Optimization-Based Coronary Artery Labeling From X-Ray Angiograms. IEEE J Biomed Health Inform 2016; 20:1608-1620. [DOI: 10.1109/jbhi.2015.2485227] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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8
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Blanchard R, Morin C, Malandrino A, Vella A, Sant Z, Hellmich C. Patient-specific fracture risk assessment of vertebrae: A multiscale approach coupling X-ray physics and continuum micromechanics. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2016; 32:e02760. [PMID: 26666734 DOI: 10.1002/cnm.2760] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 10/14/2015] [Indexed: 06/05/2023]
Abstract
While in clinical settings, bone mineral density measured by computed tomography (CT) remains the key indicator for bone fracture risk, there is an ongoing quest for more engineering mechanics-based approaches for safety analyses of the skeleton. This calls for determination of suitable material properties from respective CT data, where the traditional approach consists of regression analyses between attenuation-related grey values and mechanical properties. We here present a physics-oriented approach, considering that elasticity and strength of bone tissue originate from the material microstructure and the mechanical properties of its elementary components. Firstly, we reconstruct the linear relation between the clinically accessible grey values making up a CT, and the X-ray attenuation coefficients quantifying the intensity losses from which the image is actually reconstructed. Therefore, we combine X-ray attenuation averaging at different length scales and over different tissues, with recently identified 'universal' composition characteristics of the latter. This gives access to both the normally non-disclosed X-ray energy employed in the CT-device and to in vivo patient-specific and location-specific bone composition variables, such as voxel-specific mass density, as well as collagen and mineral contents. The latter feed an experimentally validated multiscale elastoplastic model based on the hierarchical organization of bone. Corresponding elasticity maps across the organ enter a finite element simulation of a typical load case, and the resulting stress states are increased in a proportional fashion, so as to check the safety against ultimate material failure. In the young patient investigated, even normal physiological loading is probable to already imply plastic events associated with the hydrated mineral crystals in the bone ultrastructure, while the safety factor against failure is still as high as five. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Romane Blanchard
- TU Wien-Vienna University of Technology, Institute for Mechanics of Materials and Structures, Karlsplatz 13/202, Vienna 1040, Austria
| | - Claire Morin
- CIS-EMSE, CNRS:UMR 5307, LGF, Ecole Nationale Supérieure des Mines, Saint-Etienne, F-42023, France
| | - Andrea Malandrino
- Institute for Bioengineering of Catalonia, C/Baldiri Reixac 10-12, Barcelona 08028, Spain
| | - Alain Vella
- Mechanical Engineering Department, University of Malta, Tal Qroqq, Msida MSD, 2080, Malta
| | - Zdenka Sant
- Mechanical Engineering Department, University of Malta, Tal Qroqq, Msida MSD, 2080, Malta
| | - Christian Hellmich
- TU Wien-Vienna University of Technology, Institute for Mechanics of Materials and Structures, Karlsplatz 13/202, Vienna 1040, Austria
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9
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Multi-scale Modeling of the Cardiovascular System: Disease Development, Progression, and Clinical Intervention. Ann Biomed Eng 2016; 44:2642-60. [PMID: 27138523 DOI: 10.1007/s10439-016-1628-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 04/22/2016] [Indexed: 12/19/2022]
Abstract
Cardiovascular diseases (CVDs) are the leading cause of death in the western world. With the current development of clinical diagnostics to more accurately measure the extent and specifics of CVDs, a laudable goal is a better understanding of the structure-function relation in the cardiovascular system. Much of this fundamental understanding comes from the development and study of models that integrate biology, medicine, imaging, and biomechanics. Information from these models provides guidance for developing diagnostics, and implementation of these diagnostics to the clinical setting, in turn, provides data for refining the models. In this review, we introduce multi-scale and multi-physical models for understanding disease development, progression, and designing clinical interventions. We begin with multi-scale models of cardiac electrophysiology and mechanics for diagnosis, clinical decision support, personalized and precision medicine in cardiology with examples in arrhythmia and heart failure. We then introduce computational models of vasculature mechanics and associated mechanical forces for understanding vascular disease progression, designing clinical interventions, and elucidating mechanisms that underlie diverse vascular conditions. We conclude with a discussion of barriers that must be overcome to provide enhanced insights, predictions, and decisions in pre-clinical and clinical applications.
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10
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Hossain SS, Zhang Y, Fu X, Brunner G, Singh J, Hughes TJR, Shah D, Decuzzi P. Magnetic resonance imaging-based computational modelling of blood flow and nanomedicine deposition in patients with peripheral arterial disease. J R Soc Interface 2016; 12:rsif.2015.0001. [PMID: 25878124 DOI: 10.1098/rsif.2015.0001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Peripheral arterial disease (PAD) is generally attributed to the progressive vascular accumulation of lipoproteins and circulating monocytes in the vessel walls leading to the formation of atherosclerotic plaques. This is known to be regulated by the local vascular geometry, haemodynamics and biophysical conditions. Here, an isogeometric analysis framework is proposed to analyse the blood flow and vascular deposition of circulating nanoparticles (NPs) into the superficial femoral artery (SFA) of a PAD patient. The local geometry of the blood vessel and the haemodynamic conditions are derived from magnetic resonance imaging (MRI), performed at baseline and at 24 months post intervention. A dramatic improvement in blood flow dynamics is observed post intervention. A 500% increase in peak flow rate is measured in vivo as a consequence of luminal enlargement. Furthermore, blood flow simulations reveal a 32% drop in the mean oscillatory shear index, indicating reduced disturbed flow post intervention. The same patient information (vascular geometry and blood flow) is used to predict in silico in a simulation of the vascular deposition of systemically injected nanomedicines. NPs, targeted to inflammatory vascular molecules including VCAM-1, E-selectin and ICAM-1, are predicted to preferentially accumulate near the stenosis in the baseline configuration, with VCAM-1 providing the highest accumulation (approx. 1.33 and 1.50 times higher concentration than that of ICAM-1 and E-selectin, respectively). Such selective deposition of NPs within the stenosis could be effectively used for the detection and treatment of plaques forming in the SFA. The presented MRI-based computational protocol can be used to analyse data from clinical trials to explore possible correlations between haemodynamics and disease progression in PAD patients, and potentially predict disease occurrence as well as the outcome of an intervention.
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Affiliation(s)
- Shaolie S Hossain
- Department of Translational Imaging, Houston Methodist Hospital Research Institute, Houston, TX, USA Department of Nanomedicine, Houston Methodist Hospital Research Institute, Houston, TX, USA
| | - Yongjie Zhang
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Xiaoyi Fu
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Gerd Brunner
- Methodist DeBakey Heart and Vascular Center, Houston Methodist Hospital Research Institute, Houston, TX, USA Division of Atherosclerosis and Vascular Medicine, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Jaykrishna Singh
- Department of Translational Imaging, Houston Methodist Hospital Research Institute, Houston, TX, USA Department of Nanomedicine, Houston Methodist Hospital Research Institute, Houston, TX, USA
| | - Thomas J R Hughes
- Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX, USA
| | - Dipan Shah
- Methodist DeBakey Heart and Vascular Center, Houston Methodist Hospital Research Institute, Houston, TX, USA
| | - Paolo Decuzzi
- Department of Translational Imaging, Houston Methodist Hospital Research Institute, Houston, TX, USA Department of Nanomedicine, Houston Methodist Hospital Research Institute, Houston, TX, USA
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Lee CC, Reardon MA, Ball BZ, Chen CJ, Yen CP, Xu Z, Wintermark M, Sheehan J. The predictive value of magnetic resonance imaging in evaluating intracranial arteriovenous malformation obliteration after stereotactic radiosurgery. J Neurosurg 2015; 123:136-44. [DOI: 10.3171/2014.10.jns141565] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT
The current gold standard for diagnosing arteriovenous malformation (AVM) and assessing its obliteration after stereotactic radiosurgery (SRS) is digital subtraction angiography (DSA). Recently, MRI and MR angiography (MRA) have become increasingly popular imaging modalities for the follow-up of patients with an AVM because of their convenient setup and noninvasiveness. In this study, the authors assessed the sensitivity and specificity of MRI/MRA in evaluating AVM nidus obliteration as assessed by DSA.
METHODS
The authors study a consecutive series of 136 patients who underwent SRS between January 2000 and December 2012 and who underwent regular clinical examinations, several MRI studies, and at least 1 post-SRS DSA follow- up evaluation at the University of Virginia. The average follow-up time was 47.3 months (range 10.1–165.2 months). Two blinded observers were enrolled to interpret the results of MRI/MRA compared with those of DSA. The sensitivity, specificity, positive predictive value, and negative predictive value for the obliteration of AVM were reported.
RESULTS
On the basis of DSA, 73 patients (53.7%) achieved final angiographic obliteration in a median of 28.8 months. The sensitivity (the probability of finding obliteration on MRI/MRA among those for whom complete obliteration was shown on DSA) was 84.9% for one observer (Observer 1) and 76.7% for the other (Observer 2). The specificity was 88.9% and 95.2%, respectively. The false-negative interpretations were significantly related to the presence of draining veins, perinidal edema on T2-weighted images, and the interval between the MRI/MRA and DSA studies.
CONCLUSIONS
MRI/MRA predicted AVM obliteration after SRS in most patients and can be used in their follow-up. However, because the specificity of MRI/MRA is not perfect, DSA should still be performed to confirm AVM nidus obliteration after SRS.
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Affiliation(s)
- Cheng-Chia Lee
- Departments of 1Neurological Surgery,
- 4Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital
- 5School of Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China; and
| | - Michael A. Reardon
- 3Radiology & Medical Imaging, Neuroradiology Division, University of Virginia Health System, Charlottesville, Virginia
| | | | | | | | | | - Max Wintermark
- 6Department of Radiology, Stanford University, Palo Alto, California
| | - Jason Sheehan
- Departments of 1Neurological Surgery,
- 2Radiation Oncology, and
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ISODA H, TAKEHARA Y, KOSUGI T, TERADA M, NAITO T, ONISHI Y, TANOI C, AMAYA K, SAKAHARA H. MR-based Computational Fluid Dynamics with Patient-specific Boundary Conditions for the Initiation of a Sidewall Aneurysm of a Basilar Artery. Magn Reson Med Sci 2015; 14:139-44. [DOI: 10.2463/mrms.2014-0003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Haruo ISODA
- Department of Brain & Mind Sciences, Nagoya University Graduate School of Medicine
- Brain & Mind Research Center, Nagoya University
| | | | | | - Masaki TERADA
- Department of Diagnostic Radiological Technology, Iwata City Hospital
| | - Takehiro NAITO
- Department of Neurosurgery, Iwata City Hospital
- Department of Neurosurgery, Kasugai Municipal Hospital
| | - Yuki ONISHI
- Department of Mechanical and Environmental Informatics, Tokyo Institute of Technology, Graduate School of Information Science and Engineering
| | | | - Kenji AMAYA
- Department of Mechanical and Environmental Informatics, Tokyo Institute of Technology, Graduate School of Information Science and Engineering
| | - Harumi SAKAHARA
- Department of Radiology, Hamamatsu University School of Medicine
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13
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Chung B, Cebral JR. CFD for Evaluation and Treatment Planning of Aneurysms: Review of Proposed Clinical Uses and Their Challenges. Ann Biomed Eng 2014; 43:122-38. [DOI: 10.1007/s10439-014-1093-6] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 08/08/2014] [Indexed: 11/29/2022]
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14
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Zhang JM, Zhong L, Su B, Wan M, Yap JS, Tham JPL, Chua LP, Ghista DN, Tan RS. Perspective on CFD studies of coronary artery disease lesions and hemodynamics: a review. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2014; 30:659-680. [PMID: 24459034 DOI: 10.1002/cnm.2625] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2013] [Revised: 10/30/2013] [Accepted: 11/04/2013] [Indexed: 06/03/2023]
Abstract
Coronary artery disease (CAD) is the most common cardiovascular disease. Early diagnosis of CAD's physiological significance is of utmost importance for guiding individualized risk-tailored treatment strategies. In this paper, we first review the state-of-the-art clinical diagnostic indices to quantify the severity of CAD and the associated invasive and noninvasive imaging technologies in order to quantify the anatomical parameters of diameter stenosis, area stenosis, and hemodynamic indices of coronary flow reserve and fractional flow reserve. With the development of computational technologies and CFD methods, tremendous progress has been made in applying image-based CFD simulation techniques to elucidate the effects of hemodynamics in vascular pathophysiology toward the initialization and progression of CAD. So then, we review the advancements of CFD technologies in patient-specific modeling, involving the development of geometry reconstruction, boundary conditions, and fluid-structure interaction. Next, we review the applications of CFD to stenotic sites, in order to compute their hemodynamic parameters and study the relationship between the hemodynamic conditions and the clinical indices, to thereby assess the amount of viable myocardium and candidacy for percutaneous coronary intervention. Finally, we review the strengths and limitations of current researches of applying CFD to CAD studies.
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Affiliation(s)
- Jun-Mei Zhang
- National Heart Center Singapore, Mistri Wing 17, 3rd Hospital Avenue, 168752, Singapore
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