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Schmidt S, Bruschewski M, Flassbeck S, John K, Grundmann S, Ladd ME, Schmitter S. Phase-contrast acceleration mapping with synchronized encoding. Magn Reson Med 2021; 86:3201-3210. [PMID: 34313340 DOI: 10.1002/mrm.28948] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 06/14/2021] [Accepted: 07/15/2021] [Indexed: 11/12/2022]
Abstract
PURPOSE To develop a phase-contrast (PC) -based method for direct and unbiased quantification of the acceleration vector field by synchronization of the spatial and acceleration encoding time points. The proposed method explicitly aims at in-vitro applications, requiring high measurement accuracy, as well as the validation of clinically relevant acceleration-encoded sequences. METHODS A velocity-encoded sequence with synchronized encoding (SYNC SPI) was modified to allow direct acceleration mapping by replacing the bipolar encoding gradients with tripolar gradient waveforms. The proposed method was validated in two in-vitro flow cases: a rotation and a stenosis phantom. The thereby obtained velocity and acceleration vector fields were quantitatively compared to those acquired with conventional PC methods, as well as to theoretical data. RESULTS The rotation phantom study revealed a systematic bias of the conventional PC acceleration mapping method that resulted in an average pixel-wise relative angle between the measured and theoretical vector field of (7.8 ± 3.2)°, which was reduced to (-0.4 ± 2.7)° for the proposed SYNC SPI method. Furthermore, flow features in the stenosis phantom were displaced by up to 10 mm in the conventional PC data compared with the acceleration-encoded SYNC SPI data. CONCLUSIONS This work successfully demonstrates a highly accurate method for direct acceleration mapping. It thus complements the existing velocity-encoded SYNC SPI method to enable the direct and unbiased quantification of both the velocity and acceleration vector field for in vitro studies. Hence, this method can be used for the validation of conventional acceleration-encoded PC methods applicable in-vivo.
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Affiliation(s)
- Simon Schmidt
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany.,Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, USA
| | | | - Sebastian Flassbeck
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Department of Radiology, Center for Biomedical Imaging, New York University School of Medicine, New York, New York, USA.,Center for Advanced Imaging Innovation and Research, New York University School of Medicine, New York, New York, USA
| | - Kristine John
- Institute of Fluid Mechanics, University of Rostock, Rostock, Germany
| | - Sven Grundmann
- Institute of Fluid Mechanics, University of Rostock, Rostock, Germany
| | - Mark E Ladd
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany.,Faculty of Medicine, Heidelberg University, Heidelberg, Germany
| | - Sebastian Schmitter
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany
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Giotta Lucifero A, Baldoncini M, Bruno N, Galzio R, Hernesniemi J, Luzzi S. Shedding the Light on the Natural History of Intracranial Aneurysms: An Updated Overview. ACTA ACUST UNITED AC 2021; 57:medicina57080742. [PMID: 34440948 PMCID: PMC8400479 DOI: 10.3390/medicina57080742] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 11/16/2022]
Abstract
The exact molecular pathways underlying the multifactorial natural history of intracranial aneurysms (IAs) are still largely unknown, to the point that their understanding represents an imperative challenge in neurovascular research. Wall shear stress (WSS) promotes the genesis of IAs through an endothelial dysfunction causing an inflammatory cascade, vessel remodeling, phenotypic switching of the smooth muscle cells, and myointimal hyperplasia. Aneurysm growth is supported by endothelial oxidative stress and inflammatory mediators, whereas low and high WSS determine the rupture in sidewall and endwall IAs, respectively. Angioarchitecture, age older than 60 years, female gender, hypertension, cigarette smoking, alcohol abuse, and hypercholesterolemia also contribute to growth and rupture. The improvements of aneurysm wall imaging techniques and the implementation of target therapies targeted against inflammatory cascade may contribute to significantly modify the natural history of IAs. This narrative review strives to summarize the recent advances in the comprehension of the mechanisms underlying the genesis, growth, and rupture of IAs.
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Affiliation(s)
- Alice Giotta Lucifero
- Neurosurgery Unit, Department of Clinical-Surgical, Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy;
| | - Matías Baldoncini
- Department of Neurological Surgery, Hospital San Fernando, Buenos Aires 1646, Argentina;
| | - Nunzio Bruno
- Division of Neurosurgery, Azienda Ospedaliero Universitaria Consorziale Policlinico di Bari, 70124 Bari, Italy;
| | - Renato Galzio
- Neurosurgery Unit, Maria Cecilia Hospital, 48032 Cotignola, Italy;
| | - Juha Hernesniemi
- Juha Hernesniemi International Center for Neurosurgery, Henan Provincial People’s Hospital, Zhengzhou 450000, China;
| | - Sabino Luzzi
- Neurosurgery Unit, Department of Clinical-Surgical, Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy;
- Neurosurgery Unit, Department of Surgical Sciences, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
- Correspondence:
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Eisenmenger LB, Junn JC, Cooke D, Hetts S, Zhu C, Johnson KM, Manunga JM, Saloner D, Hess C, Kim H. Presence of Vessel Wall Hyperintensity in Unruptured Arteriovenous Malformations on Vessel Wall Magnetic Resonance Imaging: Pilot Study of AVM Vessel Wall "Enhancement". Front Neurosci 2021; 15:697432. [PMID: 34366779 PMCID: PMC8334001 DOI: 10.3389/fnins.2021.697432] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 06/28/2021] [Indexed: 01/06/2023] Open
Abstract
Purpose: High-resolution vessel wall magnetic resonance imaging (VW-MRI) could provide a way to identify high risk arteriovenous malformation (AVM) features. We present the first pilot study of clinically unruptured AVMs evaluated by high-resolution VW-MRI. Methods: A retrospective review of clinically unruptured AVMs with VW-MRI between January 1, 2016 and December 31, 2018 was performed documenting the presence or absence of vessel wall “hyperintensity,” or enhancement, within the nidus as well as perivascular enhancement and evidence of old hemorrhage (EOOH). The extent of nidal vessel wall “hyperintensity” was approximated into five groups: 0, 1–25, 26–50, 51–75, and 76–100%. Results: Of the nine cases, eight demonstrated at least some degree of vessel wall nidus “hyperintensity.” Of those eight cases, four demonstrated greater than 50% of the nidus with hyperintensity at the vessel wall, and three cases had perivascular enhancement adjacent to nidal vessels. Although none of the subjects had prior clinical hemorrhage/AVM rupture, of the six patients with available susceptibility weighted imaging to assess for remote hemorrhage, only two had subtle siderosis to suggest prior sub-clinical bleeds. Conclusion: Vessel wall “enhancement” occurs in AVMs with no prior clinical rupture. Additional studies are needed to further investigate the implication of these findings.
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Affiliation(s)
- Laura B Eisenmenger
- Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States
| | - Jacqueline C Junn
- Department of Radiology, Mount Sinai Hospital, New York, NY, United States
| | - Daniel Cooke
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States
| | - Steven Hetts
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States
| | - Chengcheng Zhu
- Department of Radiology, University of Washington, Seattle, WA, United States
| | - Kevin M Johnson
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States
| | - Jesse M Manunga
- Division of Vascular and Endovascular Surgery, Minneapolis Heart Institute, Abbott Northwestern Hospital, Minneapolis, MN, United States
| | - David Saloner
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States
| | - Christopher Hess
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States
| | - Helen Kim
- Department of Anesthesia, University of California, San Francisco, San Francisco, CA, United States
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Abstract
Cells of the vascular wall are exquisitely sensitive to changes in their mechanical environment. In healthy vessels, mechanical forces regulate signaling and gene expression to direct the remodeling needed for the vessel wall to maintain optimal function. Major diseases of arteries involve maladaptive remodeling with compromised or lost homeostatic mechanisms. Whereas homeostasis invokes negative feedback loops at multiple scales to mediate mechanobiological stability, disease progression often occurs via positive feedback that generates mechanobiological instabilities. In this review, we focus on the cell biology, wall mechanics, and regulatory pathways associated with arterial health and how changes in these processes lead to disease. We discuss how positive feedback loops arise via biomechanical and biochemical means. We conclude that inflammation plays a central role in overriding homeostatic pathways and suggest future directions for addressing therapeutic needs.
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Affiliation(s)
- Jay D Humphrey
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut 06520, USA;
| | - Martin A Schwartz
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut 06520, USA;
- Department of Cell Biology, Department of Internal Medicine (Cardiology), and Cardiovascular Research Center, Yale University, New Haven, Connecticut 06520, USA
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55
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Morphological and Hemodynamic Changes during Cerebral Aneurysm Growth. Brain Sci 2021; 11:brainsci11040520. [PMID: 33921861 PMCID: PMC8073033 DOI: 10.3390/brainsci11040520] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/05/2021] [Accepted: 04/09/2021] [Indexed: 11/17/2022] Open
Abstract
Computational fluid dynamics (CFD) has grown as a tool to help understand the hemodynamic properties related to the rupture of cerebral aneurysms. Few of these studies deal specifically with aneurysm growth and most only use a single time instance within the aneurysm growth history. The present retrospective study investigated four patient-specific aneurysms, once at initial diagnosis and then at follow-up, to analyze hemodynamic and morphological changes. Aneurysm geometries were segmented via the medical image processing software Mimics. The geometries were meshed and a computational fluid dynamics (CFD) analysis was performed using ANSYS. Results showed that major geometry bulk growth occurred in areas of low wall shear stress (WSS). Wall shape remodeling near neck impingement regions occurred in areas with large gradients of WSS and oscillatory shear index. This study found that growth occurred in areas where low WSS was accompanied by high velocity gradients between the aneurysm wall and large swirling flow structures. A new finding was that all cases showed an increase in kinetic energy from the first time point to the second, and this change in kinetic energy seems correlated to the change in aneurysm volume.
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56
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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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57
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Oliveira IL, Santos GB, Gasche JL, Militzer J, Baccin CE. Non-Newtonian Blood Modeling in Intracranial Aneurysm Hemodynamics: Impact on the Wall Shear Stress and Oscillatory Shear Index Metrics for Ruptured and Unruptured Cases. J Biomech Eng 2021; 143:1104430. [PMID: 33729441 DOI: 10.1115/1.4050539] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Indexed: 11/08/2022]
Abstract
When simulating blood flow in intracranial aneurysms (IAs), the Newtonian model seems to be ubiquitous. However, analyzing the results from the few studies on this subject, the doubt remains on whether it is necessary to use non-Newtonian models in computational fluid dynamics (CFD) simulations of cerebral vascular flows. The objective of this study is to investigate whether different rheology models would influence the hemodynamic parameters related to the wall shear stress (WSS) for ruptured and unruptured IA cases, especially because ruptured aneurysms normally have morphological features, such as lobular regions and blebs, that could trigger non-Newtonian phenomena in the blood flow due to low shear rates. Using CFD in an open-source framework, we simulated four ruptured and four unruptured patient-specific aneurysms to assess the influence of the blood modeling on the main hemodynamic variables associated with aneurysm formation, growth, and rupture. Results for WSS and oscillatory shear index (OSI) and their metrics were obtained using Casson and Carreau-Yasuda non-Newtonian models and were compared with those obtained using the Newtonian model. We found that all differences between non-Newtonian and the Newtonian models were consistent among all cases irrespective of their rupture status. We further found that the WSS at peak systole is overestimated by more than 50% by using the non-Newtonian models, but its metrics based on time and surface averaged values are less affected-the maximum relative difference among the cases is 7% for the Casson model. On the other hand, the surface-averaged OSI is underestimated by more than 30% by the non-Newtonian models. These results suggest that it is recommended to investigate different blood rheology models in IAs simulations when specific parameters to characterize the flow are needed, such as peak-systole WSS and OSI.
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Affiliation(s)
- Iago L Oliveira
- Mechanical Engineering Department, São Paulo State University (UNESP), Ilha Solteira, São Paulo 15385-000, Brazil
| | - Gabriel B Santos
- Mechanical Engineering Department, São Paulo State University (UNESP), Ilha Solteira, São Paulo 15385-000, Brazil
| | - José L Gasche
- Mechanical Engineering Department, São Paulo State University (UNESP), Ilha Solteira, São Paulo 15385-000, Brazil
| | - Julio Militzer
- Department of Mechanical Engineering, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Carlos E Baccin
- Interventional Neuroradiology, Hospital Israelita Albert Einstein, São Paulo, São Paulo 05652-900, Brazil
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Cai S, Li H, Zheng F, Kong F, Dao M, Karniadakis GE, Suresh S. Artificial intelligence velocimetry and microaneurysm-on-a-chip for three-dimensional analysis of blood flow in physiology and disease. Proc Natl Acad Sci U S A 2021; 118:e2100697118. [PMID: 33762307 PMCID: PMC8020788 DOI: 10.1073/pnas.2100697118] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Understanding the mechanics of blood flow is necessary for developing insights into mechanisms of physiology and vascular diseases in microcirculation. Given the limitations of technologies available for assessing in vivo flow fields, in vitro methods based on traditional microfluidic platforms have been developed to mimic physiological conditions. However, existing methods lack the capability to provide accurate assessment of these flow fields, particularly in vessels with complex geometries. Conventional approaches to quantify flow fields rely either on analyzing only visual images or on enforcing underlying physics without considering visualization data, which could compromise accuracy of predictions. Here, we present artificial-intelligence velocimetry (AIV) to quantify velocity and stress fields of blood flow by integrating the imaging data with underlying physics using physics-informed neural networks. We demonstrate the capability of AIV by quantifying hemodynamics in microchannels designed to mimic saccular-shaped microaneurysms (microaneurysm-on-a-chip, or MAOAC), which signify common manifestations of diabetic retinopathy, a leading cause of vision loss from blood-vessel damage in the retina in diabetic patients. We show that AIV can, without any a priori knowledge of the inlet and outlet boundary conditions, infer the two-dimensional (2D) flow fields from a sequence of 2D images of blood flow in MAOAC, but also can infer three-dimensional (3D) flow fields using only 2D images, thanks to the encoded physics laws. AIV provides a unique paradigm that seamlessly integrates images, experimental data, and underlying physics using neural networks to automatically analyze experimental data and infer key hemodynamic indicators that assess vascular injury.
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Affiliation(s)
- Shengze Cai
- Division of Applied Mathematics, Brown University, Providence, RI 02912
| | - He Li
- Division of Applied Mathematics, Brown University, Providence, RI 02912
| | - Fuyin Zheng
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
- School of Biological Sciences, Nanyang Technological University, 639798 Singapore
| | - Fang Kong
- School of Biological Sciences, Nanyang Technological University, 639798 Singapore
| | - Ming Dao
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139;
| | - George Em Karniadakis
- Division of Applied Mathematics, Brown University, Providence, RI 02912;
- School of Engineering, Brown University, Providence, RI 02912
| | - Subra Suresh
- Nanyang Technological University, 639798 Singapore
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59
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Steinlauf S, Hazan Shenberger S, Halak M, Liberzon A, Avrahami I. Aortic arch aneurysm repair - Unsteady hemodynamics and perfusion at different heart rates. J Biomech 2021; 121:110351. [PMID: 33794471 DOI: 10.1016/j.jbiomech.2021.110351] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 02/22/2021] [Indexed: 11/27/2022]
Abstract
The aortic arch aneurysm is a complex disease that requires branching of one or more aortic arch vessels and can be fatal if left untreated. In this in vitro study, we examine the effect of the treatment approach on the unsteady hemodynamics and blood perfusion to the upper vessel's in models of an aortic arch aneurysm, and of the three common repair approaches: open-chest surgical repair, chimney, and hybrid approach. A particle image velocimetry method was used to quantify the unsteady hemodynamics in the four models simulated in a mock circulatory loop, to evaluate unsteady hemodynamic parameters and measure perfusion to the brain and the upper body. According to the findings, in terms of perfusion to the brain and upper body, the surgery model has the highest flow rate comparing to the other models in most heart-rate conditions. It also shows oscillatory parameters in the upper vessels which in normal arteries are correlated with a better arterial function. Between the two endovascular procedures, the hybrid model exhibits slightly better hemodynamic characteristics than the chimney model, with lower shear stresses and more oscillatory flow and WSS in the upper vessels. The hybrid model had lower perfusion flow rates to upper vessels during rest conditions (90BPM). However, unlike the other models, perfusion in the hybrid model increased with heart rate, thus at 135 BPM, it results in flow rate to upper vessels similar to that of the chimney model. The results of this study may shed light on future endograft' design and placement techniques.
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Affiliation(s)
- Shirly Steinlauf
- Department of Mechanical Engineering and Mechatronics, Ariel University, Israel; School of Mechanical Engineering, Tel Aviv University, Tel Aviv 69978, Israel
| | | | - Moshe Halak
- Department of Vascular Surgery, the Chaim Sheba Medical Center, Tel Hashomer, Israel
| | - Alex Liberzon
- School of Mechanical Engineering, Tel Aviv University, Tel Aviv 69978, Israel
| | - Idit Avrahami
- Department of Mechanical Engineering and Mechatronics, Ariel University, Israel.
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Inflow Hemodynamics of Intracranial Aneurysms: A Comparison of Computational Fluid Dynamics and 4D Flow Magnetic Resonance Imaging. J Stroke Cerebrovasc Dis 2021; 30:105685. [PMID: 33662703 DOI: 10.1016/j.jstrokecerebrovasdis.2021.105685] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Accepted: 02/13/2021] [Indexed: 11/22/2022] Open
Abstract
PURPOSE Although the inflow hemodynamics of cerebral aneurysms are key factors in their rupture and recurrence after endovascular treatments, the most available method for inflow hemodynamics evaluation remains unestablished. We compared the efficacy of inflow hemodynamics evaluation using computational fluid dynamics (CFD) analysis and that using four-dimensional (4D) flow magnetic resonance imaging (MRI). METHODS In 23 unruptured cerebral aneurysms, the inflow hemodynamics was evaluated using both CFD and 4D flow MRI. The evaluated parameters included visually classified inflow jet patterns, the inflow rate ratio (the ratio of the inflow rate at the aneurysmal orifice to the flow rate in the proximal parent artery), and the velocity ratio (the ratio of the inflow velocity to the velocity in the proximal parent artery). The Shapiro-Wilk test was used to assess the normality of variable data, and logarithmic transformation was performed for variables with non-normal distributions. Data analysis was performed using Pearson correlation analyses and the chi-square test. RESULTS There was a significant correlation between inflow jet patterns evaluated by CFD and 4D flow MRI (p = 0.008). Moreover, there was a strong correlation between the inflow rate ratios evaluated by CFD and 4D flow MRI (r = 0.801; p <0.001). Furthermore, there was a moderate correlation between the velocity ratios measured by CFD and 4D flow MRI (r = 0.559; p = 0.008). CONCLUSION Inflow hemodynamics evaluated by CFD analysis and 4D flow MRI showed good correlations in inflow jet pattern, inflow rate ratio, and velocity ratio.
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Sun A, Zhao C, Gao Z, Deng X, Qiu H. A proposed design of flow diverter and it’s hemodynamic validation. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2021. [DOI: 10.1016/j.medntd.2020.100049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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62
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Leng X, Wan H, Li G, Jiang Y, Huang L, Siddiqui AH, Zhang X, Xiang J. Hemodynamic effects of intracranial aneurysms from stent-induced straightening of parent vessels by stent-assisted coiling embolization. Interv Neuroradiol 2021; 27:181-190. [PMID: 33641496 DOI: 10.1177/1591019921995334] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Straightening of parent vessels happens for stent-assisted coiling embolization (SACE) treatment of intracranial aneurysms. This study aims to investigate aneurysmal hemodynamic modifications caused by stent-induced vessel straightening. METHODS Stent and coil deployments of a SACE-treated distal bifurcation aneurysm by finite element method were performed first with the preoperative (not straightened, NS) and postoperative (straightened, S) vessel models respectively. Computational fluid dynamics were then performed for eight models, including (I) NS only model, (II) NS+stent model, (III) NS+coils model, (IV) NS+stent+coils model, (V) S only model, (VI) S+stent model, (VII) S+coils model, and (VIII) S+stent+coils model. Finally, changes in aneurysmal flow velocity, isovelocity surface and wall shear stress (WSS) were analyzed qualitatively and quantitatively. RESULTS The flow was less in the S models than that in the corresponding NS models. Coils blocked most of the flow into the aneurysm sac in both NS models and S models and vessel straightening had more profound effect on the high aneurysmal flow volume reduction than coiling, while stenting generated adverse effect on flow reduction. Taking the NS only model as baseline (100%), the sac-averaged velocities of models II to VIII were 112%, 36%, 42%, 45%, 39%, 12%, 13%, and high flow volumes were 119%, 21%, 30%, 10%, 8%, 3%, 3%, while the sac-averaged WSSs were 106%, 37%, 44%, 41%, 35%, 17% and 24%, respectively. CONCLUSIONS Stent-induced vessel straightening combined coil embolization has the best performance in hemodynamic modifications and may reduce the recurrence rate, whereas stenting may generate adverse effect on hemodynamic alterations.
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Affiliation(s)
- Xiaochang Leng
- ArteryFlow Technology Co., Ltd., Hangzhou, China.,School of Civil Engineering and Architecture, Nanchang University, Nanchang, China
| | - Hailin Wan
- Department of Radiology, Huashan Hospital Affiliated to Fudan University, Shanghai, China
| | - Gaohui Li
- ArteryFlow Technology Co., Ltd., Hangzhou, China
| | - Yeqing Jiang
- Department of Radiology, Huashan Hospital Affiliated to Fudan University, Shanghai, China
| | - Lei Huang
- Department of Radiology, Huashan Hospital Affiliated to Fudan University, Shanghai, China
| | - Adnan H Siddiqui
- Department of Neurosurgery and Radiology, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | - Xiaolong Zhang
- Department of Radiology, Huashan Hospital Affiliated to Fudan University, Shanghai, China
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Zhang M, Peng F, Li Y, He L, Liu A, Li R. Associations between morphology and hemodynamics of intracranial aneurysms based on 4D flow and black-blood magnetic resonance imaging. Quant Imaging Med Surg 2021; 11:597-607. [PMID: 33532260 DOI: 10.21037/qims-20-440] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Background Previous studies have hypothesized that intracranial aneurysm (IA) morphology interacts with hemodynamic conditions. Magnetic resonance imaging (MRI) provides a single image modality solution for both morphological and hemodynamic measurements for IA. This study aimed to explore the interaction between the morphology and hemodynamics of IA using black-blood MRI (BB-MRI) and 4D flow MRI. Methods A total of 97 patients with unruptured IA were recruited for this study. The IA size, size ratio (SR), and minimum wall thickness (mWT) were measured using BB-MRI. Velocity, blood flow, pulsatility index (PI), and wall shear stress (WSS) were measured with 4D flow MRI. The relationship between hemodynamic parameters and morphological indices was investigated by linear regression analysis and unpaired two-sample t-test. To determine the independent interaction, multiple linear regression analysis was further performed. Results The findings showed that mWT was negatively correlated with IA size (r=-0.665, P<0.001). Maximum blood flow in IA (FlowIA) was positively correlated with IA size (r=0.458, P<0.001). The average WSS (WSSavg) was negatively correlated with IA size (r=-0.650, P<0.001). The relationships remained the same after the multivariate analysis was adjusted for hemodynamic, morphologic, and demographic confounding factors. The WSSavg was positively correlated with mWT (r=0.528, P<0.001). In the unpaired two-sample t-test, mWT, WSSavg, and FlowIA were statistically significantly associated with the size and SR of IAs. Conclusions There is potential for BB-MRI and 4D flow MRI to provide morphological and hemodynamic information regarding IA. Blood flow, WSS, and mWT may serve as non-invasive biomarkers for IA assessments, and may contribute to a more comprehensive understanding of the mechanism of IA.
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Affiliation(s)
- Miaoqi Zhang
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Fei Peng
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.,Department of Interventional Neuroradiology, Beijing Tiantan Hospital, Capital Medical University, China.,China National Clinical Research Center for Neurological Diseases, Beijing, China
| | - Yunduo Li
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Le He
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Aihua Liu
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.,Department of Interventional Neuroradiology, Beijing Tiantan Hospital, Capital Medical University, China.,China National Clinical Research Center for Neurological Diseases, Beijing, China
| | - Rui Li
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
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Xu H, Baroli D, Veneziani A. Global Sensitivity Analysis for Patient-Specific Aortic Simulations: The Role of Geometry, Boundary Condition and Large Eddy Simulation Modeling Parameters. J Biomech Eng 2021; 143:1086637. [PMID: 32879943 DOI: 10.1115/1.4048336] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Indexed: 11/08/2022]
Abstract
Numerical simulations for computational hemodynamics in clinical settings require a combination of many ingredients, mathematical models, solvers and patient-specific data. The sensitivity of the solutions to these factors may be critical, particularly when we have a partial or noisy knowledge of data. Uncertainty quantification is crucial to assess the reliability of the results. We present here an extensive sensitivity analysis in aortic flow simulations, to quantify the dependence of clinically relevant quantities to the patient-specific geometry and the inflow boundary conditions. Geometry and inflow conditions are generally believed to have a major impact on numerical simulations. We resort to a global sensitivity analysis, (i.e., not restricted to a linearization around a working point), based on polynomial chaos expansion (PCE) and the associated Sobol' indices. We regard the geometry and the inflow conditions as the realization of a parametric stochastic process. To construct a physically consistent stochastic process for the geometry, we use a set of longitudinal-in-time images of a patient with an abdominal aortic aneurysm (AAA) to parametrize geometrical variations. Aortic flow is highly disturbed during systole. This leads to high computational costs, even amplified in a sensitivity analysis -when many simulations are needed. To mitigate this, we consider here a large Eddy simulation (LES) model. Our model depends in particular on a user-defined parameter called filter radius. We borrowed the tools of the global sensitivity analysis to assess the sensitivity of the solution to this parameter too. The targeted quantities of interest (QoI) include: the total kinetic energy (TKE), the time-average wall shear stress (TAWSS), and the oscillatory shear index (OSI). The results show that these indexes are mostly sensitive to the geometry. Also, we find that the sensitivity may be different during different instants of the heartbeat and in different regions of the domain of interest. This analysis helps to assess the reliability of in silico tools for clinical applications.
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Affiliation(s)
- Huijuan Xu
- School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332; Siemens Coporate Technology, Princeton, NJ 08540
| | - Davide Baroli
- Aachen Institute for Advanced Study in Computational Engineering Science, Aachen 52062, Germany
| | - Alessandro Veneziani
- Department of Mathematics, Emory University, Atlanta, GA 30322; Department of Computer Science, Emory University, Atlanta, GA 30322
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Deshpande A, Jamilpour N, Jiang B, Michel P, Eskandari A, Kidwell C, Wintermark M, Laksari K. Automatic segmentation, feature extraction and comparison of healthy and stroke cerebral vasculature. Neuroimage Clin 2021; 30:102573. [PMID: 33578323 PMCID: PMC7875826 DOI: 10.1016/j.nicl.2021.102573] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 01/13/2021] [Accepted: 01/16/2021] [Indexed: 02/01/2023]
Abstract
Accurate segmentation of cerebral vasculature and a quantitative assessment of its morphology is critical to various diagnostic and therapeutic purposes and is pertinent to studying brain health and disease. However, this is still a challenging task due to the complexity of the vascular imaging data. We propose an automated method for cerebral vascular segmentation without the need of any manual intervention as well as a method to skeletonize the binary segmented map to extract vascular geometric features and characterize vessel structure. We combine a Hessian-based probabilistic vessel-enhancing filtering with an active-contour-based technique to segment magnetic resonance and computed tomography angiograms (MRA and CTA) and subsequently extract the vessel centerlines and diameters to calculate the geometrical properties of the vasculature. Our method was validated using a 3D phantom of the Circle-of-Willis region, demonstrating 84% mean Dice similarity coefficient (DSC) and 85% mean Pearson's correlation coefficient (PCC) with minimal modified Hausdorff distance (MHD) error (3 surface pixels at most), and showed superior performance compared to existing segmentation algorithms upon quantitative comparison using DSC, PCC and MHD. We subsequently applied our algorithm to a dataset of 40 subjects, including 1) MRA scans of healthy subjects (n = 10, age = 30 ± 9), 2) MRA scans of stroke patients (n = 10, age = 51 ± 15), 3) CTA scans of healthy subjects (n = 10, age = 62 ± 12), and 4) CTA scans of stroke patients (n = 10, age = 68 ± 11), and obtained a quantitative comparison between the stroke and normal vasculature for both imaging modalities. The vascular network in stroke patients compared to age-adjusted healthy subjects was found to have a significantly (p < 0.05) higher tortuosity (3.24 ± 0.88 rad/cm vs. 7.17 ± 1.61 rad/cm for MRA, and 4.36 ± 1.32 rad/cm vs. 7.80 ± 0.92 rad/cm for CTA), higher fractal dimension (1.36 ± 0.28 vs. 1.71 ± 0.14 for MRA, and 1.56 ± 0.05 vs. 1.69 ± 0.20 for CTA), lower total length (3.46 ± 0.99 m vs. 2.20 ± 0.67 m for CTA), lower total volume (61.80 ± 18.79 ml vs. 34.43 ± 22.9 ml for CTA), lower average diameter (2.4 ± 0.21 mm vs. 2.18 ± 0.07 mm for CTA), and lower average branch length (4.81 ± 1.97 mm vs. 8.68 ± 2.03 mm for MRA), respectively. We additionally studied the change in vascular features with respect to aging and imaging modality. While we observed differences between features as a result of aging, statistical analysis did not show any significant differences, whereas we found that the number of branches were significantly different (p < 0.05) between the two imaging modalities (201 ± 73 for MRA vs. 189 ± 69 for CTA). Our segmentation and feature extraction algorithm can be applied on any imaging modality and can be used in the future to automatically obtain the 3D segmented vasculature for diagnosis and treatment planning as well as to study morphological changes due to stroke and other cerebrovascular diseases (CVD) in the clinic.
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Affiliation(s)
- Aditi Deshpande
- Department of Biomedical Engineering, University of Arizona, United States
| | - Nima Jamilpour
- Department of Biomedical Engineering, University of Arizona, United States
| | - Bin Jiang
- Department of Radiology, Stanford University, United States
| | - Patrik Michel
- Department of Neurology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Ashraf Eskandari
- Department of Neurology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Chelsea Kidwell
- Department of Neurology, University of Arizona, United States
| | - Max Wintermark
- Department of Radiology, Stanford University, United States
| | - Kaveh Laksari
- Department of Biomedical Engineering, University of Arizona, United States; Department of Aerospace and Mechanical Engineering, University of Arizona, United States.
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Mahrous SA, Sidik NAC, Saqr KM. Numerical study on the energy cascade of pulsatile Newtonian and power-law flow models in an ICA bifurcation. PLoS One 2021; 16:e0245775. [PMID: 33493237 PMCID: PMC7833255 DOI: 10.1371/journal.pone.0245775] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 01/07/2021] [Indexed: 11/18/2022] Open
Abstract
The complex physics and biology underlying intracranial hemodynamics are yet to be fully revealed. A fully resolved direct numerical simulation (DNS) study has been performed to identify the intrinsic flow dynamics in an idealized carotid bifurcation model. To shed the light on the significance of considering blood shear-thinning properties, the power-law model is compared to the commonly used Newtonian viscosity hypothesis. We scrutinize the kinetic energy cascade (KEC) rates in the Fourier domain and the vortex structure of both fluid models and examine the impact of the power-law viscosity model. The flow intrinsically contains coherent structures which has frequencies corresponding to the boundary frequency, which could be associated with the regulation of endothelial cells. From the proposed comparative study, it is found that KEC rates and the vortex-identification are significantly influenced by the shear-thinning blood properties. Conclusively, from the obtained results, it is found that neglecting the non-Newtonian behavior could lead to underestimation of the hemodynamic parameters at low Reynolds number and overestimation of the hemodynamic parameters by increasing the Reynolds number. In addition, we provide physical insight and discussion onto the hemodynamics associated with endothelial dysfunction which plays significant role in the pathogenesis of intracranial aneurysms.
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Affiliation(s)
- Samar A. Mahrous
- Department of Thermo-Fluid Universiti Teknologi Malaysia, Skudai, Malaysia
- College of Engineering and Technology, Arab Academy for Science, Technology and Maritime Transport, Alexandria, Egypt
- * E-mail:
| | - Nor Azwadi Che Sidik
- Department of Thermo-Fluid Universiti Teknologi Malaysia, Skudai, Malaysia
- Malaysia–Japan International Institute of Technology (MJIIT), University Teknologi Malaysia Kuala Lumpur, Kuala Lumpur, Malaysia
| | - Khalid M. Saqr
- College of Engineering and Technology, Arab Academy for Science, Technology and Maritime Transport, Alexandria, Egypt
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Zeng M, Huang Z, Tao W, Zeng F, Chen F. A retrospective longitudinal study of age-related shifts and deformations in the basilar artery bifurcation. Neuroradiology 2021; 63:1305-1311. [PMID: 33475769 DOI: 10.1007/s00234-021-02644-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 01/11/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE Previous studies have indicated that cerebral arterial morphology is linked to aging and some cerebrovascular diseases. However, the mechanisms of morphological changes remain unclear. This study evaluated age-related positional changes in the basilar artery (BA) bifurcation based on longitudinal computed tomography angiography (CTA) data. METHODS This retrospective study evaluated clinical and imaging data from 72 subjects who underwent two CTA scans between July 2011 and August 2019. Three-dimensional (3D) models were reconstructed for each subject based on the two CTA scans with the longest separating interval. Skull landmarks were used to fuse the two models, and the fused model was used to evaluate positional changes in the BA bifurcation. Univariable and multivariable analyses were used to identify variables that were correlated to BA bifurcation shifting. Pearson's correlation test was used to analyze the correlation between the shifting distance and change in the BA bifurcation angle. RESULTS Significant differences between aneurysm and non-aneurysm cases were observed in terms of sex (p = 0.004), CTA scan interval (p = 0.023), and BA bifurcation shifting distance (p = 0.007). Multivariable linear regression analysis revealed that the BA bifurcation shifting distance was significantly correlated with the CTA scan interval (p = 0.038) and the presence of aneurysms (p < 0.001). Furthermore, the shifting distance was positively correlated with widening of the BA bifurcation angle (p = 0.002). CONCLUSIONS Aging-related widening of the BA bifurcation angle may be related to distal shifting of the BA bifurcation's position, and larger distal shifting of the BA bifurcation may be associated with the risk of aneurysm formation.
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Affiliation(s)
- Ming Zeng
- Departments of Neurosurgery, Xiangya Hospital, Central South University, Xiangya Road 87, Kaifu District, Changsha, 410008, China
| | - Zheng Huang
- Departments of Neurosurgery, Xiangya Hospital, Central South University, Xiangya Road 87, Kaifu District, Changsha, 410008, China
| | - Wengui Tao
- Departments of Neurosurgery, Xiangya Hospital, Central South University, Xiangya Road 87, Kaifu District, Changsha, 410008, China
| | - Feiyue Zeng
- Department of Radiology, Xiangya Hospital, Central South University, Xiangya Road 87, Kaifu District, Changsha, 410008, China
| | - Fenghua Chen
- Departments of Neurosurgery, Xiangya Hospital, Central South University, Xiangya Road 87, Kaifu District, Changsha, 410008, China.
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Schmidt S, Flassbeck S, Schmelter S, Schmeyer E, Ladd ME, Schmitter S. The impact of 4D flow displacement artifacts on wall shear stress estimation. Magn Reson Med 2021; 85:3154-3168. [PMID: 33421221 DOI: 10.1002/mrm.28641] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 11/16/2020] [Accepted: 11/23/2020] [Indexed: 12/27/2022]
Abstract
PURPOSE To investigate the amplitude and spatial distribution of errors in wall shear stress (WSS) values derived from 4D flow measurements caused by displacement artifacts intrinsic to the 4D flow acquisition. METHODS Phase-contrast MRI velocimetry was performed in a model of a stenotic aorta using two different timing schemes, both of which are commonly applied in vivo but differ in their resulting displacement artifacts. Whereas one scheme is optimized to minimize the duration of the encoding gradients (herein called FAST), the other aims to specifically minimize displacement artifacts by synchronizing all three spatial-encoding time points (called ECHO). WSS estimates were calculated and compared to unbiased WSS values obtained by a 5-hour single-point imaging acquisition. In addition, MRI simulations based on computational fluid dynamics data were carried out to investigate the impact of gradient timings corresponding to different spatial resolutions. RESULTS 4D flow displacement artifacts were found to have an impact on the quantified WSS peak values, spatial location, and overall WSS pattern. FAST leads to the underestimation of local WSS values in the phantom arch by up to 90%. Moreover, the corresponding WSS estimates depend on the image orientation. This effect was avoided using ECHO, which, however, results in biased WSS values within the stenosis, yielding an underestimation of peak WSS by up to 17%. Computational fluid dynamics-based simulation results show that the bias in WSS due to displacement artifacts increases with increasing spatial resolution, thus counteracting the resolution benefit for WSS due to reduced partial volume effects and segmentation errors. CONCLUSIONS 4D flow displacement artifacts can significantly impact the WSS estimates and depend on the timing scheme as well as potentially the image orientation. Whereas FAST might allow correct WSS estimation for lower resolutions, ECHO is recommended especially when spatial resolutions of 1 mm and smaller are used. Users need to be aware of this nonnegligible effect, particularly when conducting inter-site studies or studies between vendors. The timing scheme should thus be explicitly mentioned in publications.
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Affiliation(s)
- Simon Schmidt
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany
| | - Sebastian Flassbeck
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.,Center for Advanced Imaging Innovation and Research, New York University School of Medicine, New York, NY, USA
| | - Sonja Schmelter
- Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany
| | - Ellen Schmeyer
- Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany
| | - Mark E Ladd
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany.,Faculty of Medicine, Heidelberg University, Heidelberg, Germany
| | - Sebastian Schmitter
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany
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69
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Settecase F, Rayz VL. Advanced vascular imaging techniques. HANDBOOK OF CLINICAL NEUROLOGY 2021; 176:81-105. [DOI: 10.1016/b978-0-444-64034-5.00016-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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70
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Ishida F, Tsuji M, Tanioka S, Tanaka K, Yoshimura S, Suzuki H. Computational Fluid Dynamics for Cerebral Aneurysms in Clinical Settings. ACTA NEUROCHIRURGICA. SUPPLEMENT 2021; 132:27-32. [PMID: 33973025 DOI: 10.1007/978-3-030-63453-7_4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hemodynamics is thought to play an important role in the pathogenesis of cerebral aneurysms and recent development of computer technology makes it possible to simulate blood flow using high-resolution 3D images within several hours. A lot of studies of computational fluid dynamics (CFD) for cerebral aneurysms were reported; therefore, application of CFD for cerebral aneurysms in clinical settings is reviewed in this article.CFD for cerebral aneurysms using a patient-specific geometry model was first reported in 2003 and it has been revealing that hemodynamics brings a certain contribution to understanding aneurysm pathology, including initiation, growth and rupture. Based on the knowledge of the state-of-the-art techniques, this review treats the decision-making process for using CFD in several clinical settings. We introduce our CFD procedure using digital imaging and communication in medicine (DICOM) datasets of 3D CT angiography or 3D rotational angiography. In addition, we review rupture status, hyperplastic remodeling of aneurysm wall, and recurrence of coiled aneurysms using the hemodynamic parameters such as wall shear stress (WSS), oscillatory shear index (OSI), aneurysmal inflow rate coefficient (AIRC), and residual flow volume (RFV).
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Affiliation(s)
- Fujimaro Ishida
- Department of Neurosurgery, Mie Chuo Medical Center, NHO, Tsu, Japan.
| | - Masanori Tsuji
- Department of Neurosurgery, Mie Chuo Medical Center, NHO, Tsu, Japan
| | - Satoru Tanioka
- Department of Neurosurgery, Mie Chuo Medical Center, NHO, Tsu, Japan
| | - Katsuhiro Tanaka
- Department of Neurosurgery, Mie Chuo Medical Center, NHO, Tsu, Japan
| | | | - Hidenori Suzuki
- Department of Neurosurgery, Mie University Graduate School of Medicine, Tsu, Mie, Japan
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Tian X, Cai G, Zhi D, Fan K, Song ZL, Qiu B, Jia L, Gao R. A Transparent Vessel-on-a-Chip Device for Hemodynamic Analysis and Early Diagnosis of Intracranial Aneurysms by CFD and PC-MRI. ACS Sens 2020; 5:4064-4071. [PMID: 33289559 DOI: 10.1021/acssensors.0c02164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Hemodynamics plays a critical role in early diagnosis and investigating the growth mechanism of intracranial aneurysms (IAs), which usually induce hemorrhagic stroke, serious neurological diseases, and even death. We developed a transparent blood vessel-on-a-chip (VOC) device for magnetic resonance imaging (MRI) to provide characteristic flow fields of early IAs as the reference for early diagnosis. This VOC device takes advantage of the transparent property to clearly exhibit the internal structure and identify the needless air bubbles in the biomimetic fluid experiment, which significantly affects the MRI image quality. Furthermore, the device was miniaturized and easily assembled with arbitrary direction using a 3D-printed scaffold in a radiofrequency coil. Computational fluid dynamics (CFD) simulations of the flow field were greatly consistent with those data from MRI. Both internal flow and wall shear stress (WSS) exhibited very low levels during the IA growth, thus leading to the growth and rupture of IAs. PC-MRI images can also provide a reasonable basis for the early diagnosis of IAs. Therefore, we believed that this proposed VOC-based MR imaging technique has great potential for early diagnostic of intracranial aneurysms.
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Affiliation(s)
- Xin Tian
- School of Instrument Science and Opto-electronic Engineering, Hefei University of Technology, Hefei 230009, China
- Department of Medical Imaging and Neurology, Jincheng People’s Hospital, Jincheng 048000, China
| | - Guochao Cai
- School of Instrument Science and Opto-electronic Engineering, Hefei University of Technology, Hefei 230009, China
| | - Debo Zhi
- Department of Electronic Science and Technology, University of Science and Technology of China, Hefei 230027, China
| | - Ka Fan
- Department of Medical Imaging and Neurology, Jincheng People’s Hospital, Jincheng 048000, China
| | - Zhi-ling Song
- Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, MOE, Shandong Key Laboratory of Biochemical Analysis, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Bensheng Qiu
- Department of Electronic Science and Technology, University of Science and Technology of China, Hefei 230027, China
| | - Longbin Jia
- Department of Medical Imaging and Neurology, Jincheng People’s Hospital, Jincheng 048000, China
| | - Rongke Gao
- School of Instrument Science and Opto-electronic Engineering, Hefei University of Technology, Hefei 230009, China
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Chu C, Xu G, Li X, Duan Z, Tao L, Cai H, Yang M, Zhang X, Chen B, Zheng Y, Shi H, Li X. Sustained expression of MCP-1 induced low wall shear stress loading in conjunction with turbulent flow on endothelial cells of intracranial aneurysm. J Cell Mol Med 2020; 25:110-119. [PMID: 33332775 PMCID: PMC7810920 DOI: 10.1111/jcmm.15868] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 07/30/2020] [Accepted: 08/24/2020] [Indexed: 12/28/2022] Open
Abstract
Shear stress was reported to regulate the expression of AC007362, but its underlying mechanisms remain to be explored. In this study, to isolate endothelial cells of blood vessels, unruptured and ruptured intracranial aneurysm (IA) tissues were collected from IA patients. Subsequently, quantitative real‐time PCR (qRT‐PCR), Western blot and luciferase assay were performed to investigate the relationships between AC007362, miRNAs‐493 and monocyte chemoattractant protein‐1 (MCP‐1) in human umbilical vein endothelial cells (HUVECs) exposed to shear stress. Reduced representation bisulphite sequencing (RRBS) was performed to assess the level of DNA methylation in AC007362 promoter. Accordingly, AC007362 and MCP‐1 were significantly up‐regulated while miR‐493 was significantly down‐regulated in HUVECs exposed to shear stress. AC007362 could suppress the miR‐493 expression and elevate the MCP‐1 expression, and miR‐493 was shown to respectively target AC007362 and MCP‐1. Moreover, shear stress in HUVECs led to the down‐regulated DNA methyltransferase 1 (DNMT1), as well as the decreased DNA methylation level of AC007362 promoter. Similar results were also observed in ruptured IA tissues when compared with unruptured IA tissues. In conclusion, this study presented a deep insight into the operation of the regulatory network of AC007362, miR‐493 and MCP‐1 upon shear stress. Under shear stress, the expression of AC007362 was enhanced by the inhibited promoter DNA methylation, while the expression of MCP‐1 was enhanced by sponging the expression of miR‐493.
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Affiliation(s)
- Cheng Chu
- Department of Neurology, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Gang Xu
- Department of Neurology, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Xiaocong Li
- Department of Neurology, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Zuowei Duan
- Department of Neurology, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Lihong Tao
- Department of Neurology, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Hongxia Cai
- Department of Neurology, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Ming Yang
- Department of Neurology, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Xinjiang Zhang
- Department of Neurology, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Bin Chen
- Department of Neurology, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Yanyu Zheng
- Department of Neurology, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Hongcan Shi
- Department of Neurology, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Xiaoyu Li
- Department of Pathophysiology, Key Laboratory of Cardiovascular Disease and Molecular Intervention, Nanjing Medical University, Nanjing, China
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A review of hemodynamic parameters in cerebral aneurysm. INTERDISCIPLINARY NEUROSURGERY-ADVANCED TECHNIQUES AND CASE MANAGEMENT 2020. [DOI: 10.1016/j.inat.2020.100716] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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74
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Youn SW, Lee J. From 2D to 4D Phase-Contrast MRI in the Neurovascular System: Will It Be a Quantum Jump or a Fancy Decoration? J Magn Reson Imaging 2020; 55:347-372. [PMID: 33236488 DOI: 10.1002/jmri.27430] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 10/20/2020] [Accepted: 10/21/2020] [Indexed: 12/16/2022] Open
Abstract
Considering the crosstalk between the flow and vessel wall, hemodynamic assessment of the neurovascular system may offer a well-integrated solution for both diagnosis and management by adding prognostic significance to the standard CT/MR angiography. 4D flow MRI or time-resolved 3D velocity-encoded phase-contrast MRI has long been promising for the hemodynamic evaluation of the great vessels, but challenged in clinical studies for assessing intracranial vessels with small diameter due to long scan times and low spatiotemporal resolution. Current accelerated MRI techniques, including parallel imaging with compressed sensing and radial k-space undersampling acquisitions, have decreased scan times dramatically while preserving spatial resolution. 4D flow MRI visualized and measured 3D complex flow of neurovascular diseases such as aneurysm, arteriovenous shunts, and atherosclerotic stenosis using parameters including flow volume, velocity vector, pressure gradients, and wall shear stress. In addition to the noninvasiveness of the phase contrast technique and retrospective flow measurement through the wanted windows of the analysis plane, 4D flow MRI has shown several advantages over Doppler ultrasound or computational fluid dynamics. The evaluation of the flow status and vessel wall can be performed simultaneously in the same imaging modality. This article is an overview of the recent advances in neurovascular 4D flow MRI techniques and their potential clinical applications in neurovascular disease. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 3.
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Affiliation(s)
- Sung Won Youn
- Department of Radiology, Catholic University of Daegu School of Medicine, Daegu, Korea
| | - Jongmin Lee
- Department of Radiology and Biomedical Engineering, Kyungpook National University School of Medicine, Daegu, Korea
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Wan H, Lu G, Huang L, Ge L, Jiang Y, Li G, Leng X, Xiang J, Zhang X. Hemodynamic Effect of the Last Finishing Coils in Packing the Aneurysm Neck. Front Neurol 2020; 11:598412. [PMID: 33329354 PMCID: PMC7714910 DOI: 10.3389/fneur.2020.598412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 10/15/2020] [Indexed: 11/13/2022] Open
Abstract
Background: Using the finishing coils to densely pack the aneurysm neck is necessary. However, the exact hemodynamic effect of finishing coils in packing the aneurysm neck is unknown. Objective: To evaluate the hemodynamic characteristics of finishing coils to densely pack the aneurysm neck, using finite element method simulation. Methods: A computational study was performed based on a 44-year-old female patient with an unruptured wide-necked carotid-ophthalmic artery aneurysm treated with low-profile visualized intraluminal support stent-assisted coil embolization. Four computational fluid dynamics models including pre-treatment, post-stenting, common stent-assisted coil embolization (SACE), and common SACE with finishing coils were evaluated qualitatively and quantitatively. Results: Compared with the baseline of pretreatment model (100%), sac-averaged velocity in post-stenting, common SACE, and common SACE with finishing coil models decreased to 95.68%, 24.38%, and 13.20%, respectively; high flow volume (>0.1 m/s) around the aneurysm neck decreased to 92.19%, 9.59%, and 5.57%, respectively; and mean wall shear stress increased or decreased to 107%, 25.94%, and 23.89%, respectively. Conclusion: Finishing coils to densely pack the aneurysm neck can generate favorable hemodynamic modifications, which may decrease the recurrence.
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Affiliation(s)
- Hailin Wan
- Huashan Hospital, Fudan University, Shanghai, China
| | - Gang Lu
- Huashan Hospital, Fudan University, Shanghai, China
| | - Lei Huang
- Huashan Hospital, Fudan University, Shanghai, China
| | - Liang Ge
- Huashan Hospital, Fudan University, Shanghai, China
| | - Yeqing Jiang
- Huashan Hospital, Fudan University, Shanghai, China
| | - Gaohui Li
- ArteryFlow Technology Co., Ltd, Hangzhou, China
| | | | | | - Xiaolong Zhang
- Huashan Hospital, Fudan University, Shanghai, China
- *Correspondence: Xiaolong Zhang
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Juffermans JF, Westenberg JJM, van den Boogaard PJ, Roest AAW, van Assen HC, van der Palen RLF, Lamb HJ. Reproducibility of Aorta Segmentation on 4D Flow MRI in Healthy Volunteers. J Magn Reson Imaging 2020; 53:1268-1279. [PMID: 33179389 PMCID: PMC7984392 DOI: 10.1002/jmri.27431] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 10/20/2020] [Accepted: 10/20/2020] [Indexed: 12/21/2022] Open
Abstract
Background Hemodynamic aorta parameters can be derived from 4D flow MRI, but this requires lumen segmentation. In both commercially available and research 4D flow MRI software tools, lumen segmentation is mostly (semi‐)automatically performed and subsequently manually improved by an observer. Since the segmentation variability, together with 4D flow MRI data and image processing algorithms, will contribute to the reproducibility of patient‐specific flow properties, the observer's lumen segmentation reproducibility and repeatability needs to be assessed. Purpose To determine the interexamination, interobserver reproducibility, and intraobserver repeatability of aortic lumen segmentation on 4D flow MRI. Study Type Prospective and retrospective. Population A healthy volunteer cohort of 10 subjects who underwent 4D flow MRI twice. Also, a clinical cohort of six subjects who underwent 4D flow MRI once. Field Strength/Sequence 3T; time‐resolved three‐directional and 3D velocity‐encoded sequence (4D flow MRI). Assessment The thoracic aorta was segmented on the 4D flow MRI in five systolic phases. By positioning six planes perpendicular to a segmentation's centerline, the aorta was divided into five segments. The volume, surface area, centerline length, maximal diameter, and curvature radius were determined for each segment. Statistical Tests To assess the reproducibility, the coefficient of variation (COV), Pearson correlation coefficient (r), and intraclass correlation coefficient (ICC) were calculated. Results The interexamination and interobserver reproducibility and intraobserver repeatability were comparable for each parameter. For both cohorts there was very good reproducibility and repeatability for volume, surface area, and centerline length (COV = 10–32%, r = 0.54–0.95 and ICC = 0.65–0.99), excellent reproducibility and repeatability for maximal diameter (COV = 3–11%, r = 0.94–0.99, ICC = 0.94–0.99), and good reproducibility and repeatability for curvature radius (COV = 25–62%, r = 0.73–0.95, ICC = 0.84–0.97). Data Conclusion This study demonstrated no major reproducibility and repeatability limitations for 4D flow MRI aortic lumen segmentation. Level of Evidence 3 Technical Efficacy Stage 2
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Affiliation(s)
- Joe F Juffermans
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Jos J M Westenberg
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Arno A W Roest
- Department of Paediatric Cardiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Hans C van Assen
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Roel L F van der Palen
- Department of Paediatric Cardiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Hildo J Lamb
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
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Munarriz PM, Bárcena E, Alén JF, Castaño-Leon AM, Paredes I, Moreno-Gómez LM, García-Pérez D, Jiménez-Roldán L, Gómez PA, Lagares A. Reliability and accuracy assessment of morphometric measurements obtained with software for three-dimensional reconstruction of brain aneurysms relative to cerebral angiography measures. Interv Neuroradiol 2020; 27:191-199. [PMID: 32996346 DOI: 10.1177/1591019920961588] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To analyze the reliability and accuracy of morphological measurements of software employed to three-dimensionally reconstruct aneurysms and vessels (VMTKlab, version 1.6.1,) with computed tomography angiography (CTA) as the source of images. Agreement with measurements from three-dimensional digital subtraction angiography (3 D-DSA) was evaluated. METHODS We evaluated 40 patients presenting with aneurysmal subarachnoid hemorrhage (aSAH). We analyzed four main variables of the aneurysm morphology: absolute height (size), neck (maximum neck width), perpendicular height, and maximum width. The CTA images were uploaded to the software and then segmented to reconstruct the aneurysm. This new method was compared to the current gold standard-3D reconstruction of pretreatment cerebral angiography. We used intraclass correlation coefficient (ICC) and Bland-Altman plot analyses to evaluate the agreement between these methods. RESULTS The ICCs obtained for absolute height, neck, perpendicular height, and maximum width were 0.85, 0.57, 0.85, and 0.89, respectively. This implied good agreement except for the neck of the aneurysm (moderate agreement). Bland-Altman plots are presented for the four indexes. The average of the differences was not significant in terms of absolute height, perpendicular height, and maximum width indicating good agreement. However, it was significant for the neck of the aneurysm. CONCLUSIONS We report good agreement between the values generated using VMTKlab and cerebral angiography for three of the four main variables. Discrepancies in neck diameter are not surprising and its underestimation with a traditional delineation from cerebral angiography has been reported before.
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Affiliation(s)
- Pablo M Munarriz
- Department of Neurosurgery, Hospital Universitario 12 de Octubre, Instituto de Investigación i±12, Madrid, Spain.,Department of Surgery, Universidad Complutense de Madrid, Madrid, Spain
| | - Eduardo Bárcena
- Department of Radiology, Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Jose F Alén
- Department of Radiology, Hospital Universitario 12 de Octubre, Madrid, Spain.,Department of Neurosurgery, Hospital Universitario La Princesa, Madrid, Spain
| | - Ana M Castaño-Leon
- Department of Neurosurgery, Hospital Universitario 12 de Octubre, Instituto de Investigación i±12, Madrid, Spain.,Department of Surgery, Universidad Complutense de Madrid, Madrid, Spain
| | - Igor Paredes
- Department of Neurosurgery, Hospital Universitario 12 de Octubre, Instituto de Investigación i±12, Madrid, Spain.,Department of Surgery, Universidad Complutense de Madrid, Madrid, Spain
| | - Luis Miguel Moreno-Gómez
- Department of Neurosurgery, Hospital Universitario 12 de Octubre, Instituto de Investigación i±12, Madrid, Spain
| | - Daniel García-Pérez
- Department of Neurosurgery, Hospital Universitario 12 de Octubre, Instituto de Investigación i±12, Madrid, Spain
| | - Luis Jiménez-Roldán
- Department of Neurosurgery, Hospital Universitario 12 de Octubre, Instituto de Investigación i±12, Madrid, Spain.,Department of Surgery, Universidad Complutense de Madrid, Madrid, Spain
| | - Pedro A Gómez
- Department of Neurosurgery, Hospital Universitario 12 de Octubre, Instituto de Investigación i±12, Madrid, Spain.,Department of Surgery, Universidad Complutense de Madrid, Madrid, Spain
| | - Alfonso Lagares
- Department of Neurosurgery, Hospital Universitario 12 de Octubre, Instituto de Investigación i±12, Madrid, Spain.,Department of Surgery, Universidad Complutense de Madrid, Madrid, Spain
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Samaniego EA, Roa JA, Zhang H, Koscik TR, Ortega-Gutierrez S, Bathla G, Sonka M, Derdeyn C, Magnotta VA, Hasan D. Increased contrast enhancement of the parent vessel of unruptured intracranial aneurysms in 7T MR imaging. J Neurointerv Surg 2020; 12:1018-1022. [PMID: 32424006 DOI: 10.1136/neurintsurg-2020-015915] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/26/2020] [Accepted: 04/04/2020] [Indexed: 01/14/2023]
Abstract
BACKGROUND Inflammation of the arterial wall may lead to aneurysm formation. The presence of aneurysm enhancement on high-resolution vessel wall imaging (HR-VWI) is a marker of wall inflammation and instability. We aim to determine if there is any association between increased contrast enhancement in the aneurysmal wall and its parent artery. METHODS Patients with unruptured intracranial aneurysms (UIAs) prospectively underwent 7T HR-VWI. Regions of interest were selected manually and with a semi-automated protocol based on gradient algorithms of intensity patterns. Mean signal intensities in pre- and post-contrast T1-weighted sequences were adjusted to the enhancement of the pituitary stalk and then subtracted to objectively determine: circumferential aneurysmal wall enhancement (CAWE); parent vessel enhancement (PVE); and reference vessel enhancement (RVE). PVE was assessed over regions located 3- and 5 mm from the aneurysm's neck. RVE was assessed in arteries located in a different vascular territory. RESULTS Twenty-five UIAs were analyzed. There was a significant moderate correlation between CAWE and 5 mm PVE (Pearson R=0.52, P=0.008), whereas no correlation was found between CAWE and RVE (Pearson R=0.20, P=0.33). A stronger correlation was found between CAWE and 3 mm PVE (Pearson R=0.78, P<0.001). Intra-class correlation analysis demonstrated good reliability between measurements obtained using semi-automated and manual segmentation (ICC coefficient=0.790, 95% CI 0.58 to 0.90). CONCLUSION Parent arteries exhibit higher contrast enhancement in regions closer to the aneurysm's neck, especially in aneurysms≥7 mm. A localized inflammatory/vasculopathic process in the wall of the parent artery may lead to aneurysm formation and growth.
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Affiliation(s)
- Edgar A Samaniego
- Interventional Neuroradiology/Endovascular Neurosurgery Division Department of Neurology, Neurosurgery and Radiology, The University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Jorge A Roa
- Department of Neurology and Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Honghai Zhang
- Department of Electrical and Computer Engineering, Iowa Institute of Biomedical Imaging, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Timothy R Koscik
- Department of Psychiatry, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Santiago Ortega-Gutierrez
- Interventional Neuroradiology/Endovascular Neurosurgery Division Department of Neurology, Neurosurgery and Radiology, The University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Girish Bathla
- Radiology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Milan Sonka
- Department of Electrical and Computer Engineering, Iowa Institute of Biomedical Imaging, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Colin Derdeyn
- Radiology and Interventional Radiology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Vincent A Magnotta
- Radiology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - David Hasan
- Neurological Surgery, The University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
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Razavi A, Sachdeva S, Frommelt PC, LaDisa JF. Patient-Specific Numerical Analysis of Coronary Flow in Children With Intramural Anomalous Aortic Origin of Coronary Arteries. Semin Thorac Cardiovasc Surg 2020; 33:155-167. [PMID: 32858220 DOI: 10.1053/j.semtcvs.2020.08.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 08/21/2020] [Indexed: 11/11/2022]
Abstract
Unroofing surgery for anomalous aortic origin of a coronary artery (AAOCA) alters coronary anatomy by opening the intramural segment so that the anomalous coronary orifice arises perpendicularly from appropriate aortic sinus. Computational fluid dynamics modeling (CFD) allows for quantification of hemodynamics linked to morbidity such as wall shear stress (WSS), relative to patient-specific features like the angle of origin (AO). We hypothesize that CFD will reveal abnormal WSS indices in unroofed arteries that are related to AO. Six AAOCA patients (3 left, 3 right) status post unroofing (median = 13.5 years, range 9-17) underwent cardiac magnetic resonance imaging. CFD models were created from pre (n = 2) and postunroofing (n = 6) cardiac magnetic resonance imaging data, for the anomalous and contralateral normally-arising arteries. Downstream vasculature was represented by lumped parameter networks. Time-averaged WSS (TAWSS) and oscillatory shear index (OSI) were quantified relative to AO and measured hemodynamics. TAWSS was elevated along the outer wall of the normally-arising left vs right coronary arteries, as well as along unroofed left vs right coronary arteries (n = 6/group). No significant differences were noted when comparing unroofed and same-sided normally-arising coronaries. TAWSS was reduced after unroofing (eg, 276 ± 28 dyne/cm2 vs 91 ± 15 dyne/cm2; n = 2/group). Models with more acute preoperative AO indicated lower TAWSS at the proximity of ostium. Differences in OSI were not significant. Different flow patterns exist natively between right and left coronary arteries. Unroofing may normalize TAWSS but with variance related to the AO. This study suggests CFD may help stratify risk in AAOCA.
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Affiliation(s)
- Atefeh Razavi
- Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin.
| | | | - Peter C Frommelt
- Children's Hospital of Wisconsin, Milwaukee, Wisconsin; Department of Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - John F LaDisa
- Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin; Department of Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin; Departments of Cardiovascular Medicine and Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
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Soldozy S, Norat P, Elsarrag M, Chatrath A, Costello JS, Sokolowski JD, Tvrdik P, Kalani MYS, Park MS. The biophysical role of hemodynamics in the pathogenesis of cerebral aneurysm formation and rupture. Neurosurg Focus 2020; 47:E11. [PMID: 31261115 DOI: 10.3171/2019.4.focus19232] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 04/18/2019] [Indexed: 11/06/2022]
Abstract
The pathogenesis of intracranial aneurysms remains complex and multifactorial. While vascular, genetic, and epidemiological factors play a role, nascent aneurysm formation is believed to be induced by hemodynamic forces. Hemodynamic stresses and vascular insults lead to additional aneurysm and vessel remodeling. Advanced imaging techniques allow us to better define the roles of aneurysm and vessel morphology and hemodynamic parameters, such as wall shear stress, oscillatory shear index, and patterns of flow on aneurysm formation, growth, and rupture. While a complete understanding of the interplay between these hemodynamic variables remains elusive, the authors review the efforts that have been made over the past several decades in an attempt to elucidate the physical and biological interactions that govern aneurysm pathophysiology. Furthermore, the current clinical utility of hemodynamics in predicting aneurysm rupture is discussed.
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Dabagh M, Nair P, Gounley J, Frakes D, Gonzalez LF, Randles A. Hemodynamic and morphological characteristics of a growing cerebral aneurysm. Neurosurg Focus 2020; 47:E13. [PMID: 31261117 DOI: 10.3171/2019.4.focus19195] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 04/29/2019] [Indexed: 11/06/2022]
Abstract
The growth of cerebral aneurysms is linked to local hemodynamic conditions, but the driving mechanisms of the growth are poorly understood. The goal of this study was to examine the association between intraaneurysmal hemodynamic features and areas of aneurysm growth, to present the key hemodynamic parameters essential for an accurate prediction of the growth, and to gain a deeper understanding of the underlying mechanisms. Patient-specific images of a growing cerebral aneurysm in 3 different growth stages acquired over a period of 40 months were segmented and reconstructed. A unique aspect of this patient-specific case study was that while one side of the aneurysm stayed stable, the other side continued to grow. This unique case enabled the authors to examine their aims in the same patient with parent and daughter arteries under the same inlet flow conditions. Pulsatile flow in the aneurysm models was simulated using computational fluid dynamics and was validated with in vitro experiments using particle image velocimetry measurements. The authors' detailed analysis of intrasaccular hemodynamics linked the growing regions of aneurysms to flow instabilities and complex vortex structures. Extremely low velocities were observed at or around the center of the unstable vortex structure, which matched well with the growing regions of the studied cerebral aneurysm. Furthermore, the authors observed that the aneurysm wall regions with a growth greater than 0.5 mm coincided with wall regions of lower (< 0.5 Pa) time-averaged wall shear stress (TAWSS), lower instantaneous (< 0.5 Pa) wall shear stress (WSS), and high (> 0.1) oscillatory shear index (OSI). To determine which set of parameters can best identify growing and nongrowing aneurysms, the authors performed statistical analysis for consecutive stages of the growing CA. The results demonstrated that the combination of TAWSS and the distance from the center of the vortical structure has the highest sensitivity and positive predictive value, and relatively high specificity and negative predictive value. These findings suggest that an unstable, recirculating flow structure within the aneurysm sac created in the region adjacent to the aneurysm wall with low TAWSS may be introduced as an accurate criterion to explain the hemodynamic conditions predisposing the aneurysm to growth. The authors' findings are based on one patient's data set, but the study lays out the justification for future large-scale verification. The authors' findings can assist clinicians in differentiating stable and growing aneurysms during preinterventional planning.
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Affiliation(s)
| | - Priya Nair
- Schools of2Biological and Health Systems Engineering and
| | | | - David Frakes
- Schools of2Biological and Health Systems Engineering and.,3Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona
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Extraluminal Sigmoid Sinus Angioplasty: A Pertinent Reconstructive Surgical Method Targeting Dural Sinus Hemodynamics to Resolve Pulsatile Tinnitus. Otol Neurotol 2020; 41:e132-e145. [PMID: 31568136 DOI: 10.1097/mao.0000000000002464] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVES 1) To provide information on the treatment of pulsatile tinnitus (PT) with transtemporal extraluminal sigmoid sinus angioplasty (ESSA); and 2) to discuss the current clinical management of PT. STUDY DESIGN This was a retrospective study. SETTINGS Multi-institutional tertiary university medical centers. PATIENTS Fifty-four PT patients with transverse-sigmoid sinus enlargement and prominent transverse-sigmoid junction with or without sigmoid sinus wall anomalies or transverse sinus anomalies. INTERVENTION All patients underwent ESSA under local anesthesia. MAIN OUTCOME MEASURES Intraoperative discoveries and surgical resolution of PT, morphology, and computational fluid dynamics. RESULTS Fifty-three of the 54 (98%) patients experienced a significant reduction in, or complete resolution of, PT after ESSA. No major surgical complications occurred, except for one case where we observed a full collapse of the sinus wall. On average, this surgery reduced the cross-sectional area at the transverse-sigmoid junction by 61.5%. Our intraoperative discoveries suggest that sigmoid sinus wall anomalies may not be a definitive cause of PT. The transverse-sigmoid sinus system was significantly larger (in term of both cross-sectional area and volume) on the ipsilesional side compared with the contralesional side. Following ESSA, the vascular wall pressure and vortex flow at the transverse-sigmoid junction decreased considerably, and the flow velocity and wall shear stress increased significantly. CONCLUSION ESSA is a highly effective surgical technique for PT patients with transverse-sigmoid sinus enlargement and prominent transverse-sigmoid junction, regardless of whether they also have sigmoid sinus wall or transverse sinus anomalies. A large transverse-sigmoid system with prominent transverse-sigmoid junction is a predisposing factor for PT, and only by improving patients' intrasinus hemodynamics could PT be resolved efficiently. In cases without complete obstruction of venous return, ESSA is safe. No postoperative complications related to neurological disorders were observed.
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84
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Gholampour S, Mehrjoo S. Effect of bifurcation in the hemodynamic changes and rupture risk of small intracranial aneurysm. Neurosurg Rev 2020; 44:1703-1712. [PMID: 32803404 DOI: 10.1007/s10143-020-01367-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/01/2020] [Accepted: 08/10/2020] [Indexed: 11/29/2022]
Abstract
The role of bifurcations is prominent in the intracranial aneurysm (IA) evaluation, and there are many contradictions and complexities in the rupture risk of small IA. Therefore, in the present study, the effect of bifurcation on the manner of hemodynamic changes and the rupture risk of the small middle cerebral artery (MCA) aneurysm is investigated. 3D anatomical models of the MCAs of 21 healthy subjects, 19 patients/IA/bifurcation, and 19 patients/IA were generated, and the models were analyzed by the computational fluid dynamic (CFD) analysis. The presence of bifurcation in the pathway of the blood flow in the parent artery of healthy subjects has reduced the maximum velocity, flow rate, and wall shear stress (WSS) by 25.8%, 38.6%, and 11.1%, respectively. The bifurcation decreased the maximum velocity and flow rate in the neck and sac of the aneurysm by 1.65~2.1 times, respectively. It increased the maximum WSS, and phase lag between the WSS graph of healthy subjects and patients by 12.8%~13.9% and 10.2%~40.4%, respectively. The effect of bifurcation on the Womersley number change in the aneurysm was insignificant, and the blood flow was in the laminar flow condition in all samples. The results also showed bifurcation increased the phase lag between the flow rate and pressure gradient graphs up to approximately 1.5 times. The rupture prediction index for patients/IA/bifurcation and patients/IA was 62.1%(CV = 4.1) and 51.8%(CV = 4.4), respectively. Thus, in equal conditions, the presence of bifurcation increased the probability of the rupture of the aneurysm by 19.9%.
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Affiliation(s)
- Seifollah Gholampour
- Department of Biomedical Engineering, North Tehran Branch, Islamic Azad University, Tehran, Iran.
| | - Saeed Mehrjoo
- Department of Biomedical Engineering, North Tehran Branch, Islamic Azad University, Tehran, Iran
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Takehara Y, Isoda H, Takahashi M, Unno N, Shiiya N, Ushio T, Goshima S, Naganawa S, Alley M, Wakayama T, Nozaki A. Abnormal Flow Dynamics Result in Low Wall Shear Stress and High Oscillatory Shear Index in Abdominal Aortic Dilatation: Initial in vivo Assessment with 4D-flow MRI. Magn Reson Med Sci 2020; 19:235-246. [PMID: 32655086 PMCID: PMC7553816 DOI: 10.2463/mrms.mp.2019-0188] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 05/13/2020] [Indexed: 12/05/2022] Open
Abstract
PURPOSE To characterize the non-laminar flow dynamics and resultant decreased wall shear stress (WSS) and high oscillatory shear index (OSI) of the infrarenal abdominal aortic dilatation, cardiac phase-resolved 3D phase-contrast MRI (4D-flow MRI) was performed. METHODS The prospective single-arm study was approved by the Institutional Review Board and included 18 subjects (median 67.5 years) with the dilated infrarenal aorta (median diameter 35 mm). 4D-flow MRI was conducted on a 1.5T MRI system. On 3D streamline images, laminar and non-laminar (i.e., vortex or helical) flow patterns were visually assessed both for the dilated aorta and for the undilated upstream aorta. Cardiac phase-resolved flow velocities, WSS and OSI, were also measured for the dilated aorta and the upstream undilated aorta. RESULTS Non-laminar flow represented by vortex or helical flow was more frequent and overt in the dilated aorta than in the undilated upstream aorta (P < 0.0156) with a very good interobserver agreement (weighted kappa: 0.82-1.0). The WSS was lower, and the OSI was higher on the dilated aortic wall compared with the proximal undilated segments. In mid-systole, mean spatially-averaged WSS was 0.20 ± 0.016 Pa for the dilated aorta vs. 0.68 ± 0.071 Pa for undilated upstream aorta (P < 0.0001), and OSI on the dilated aortic wall was 0.093 ± 0.010 vs. 0.041 ± 0.0089 (P = 0.013). The maximum values and the amplitudes of the WSS at the dilated aorta were inversely proportional to the ratio of dilated/undilated aortic diameter (r = -0.694, P = 0.0014). CONCLUSION 4D-flow can characterize abnormal non-laminar flow dynamics within the dilated aorta in vivo. The wall of the infrarenal aortic dilatation is continuously and increasingly affected by atherogenic stimuli due to the flow disturbances represented by vortex or helical flow, which is reflected by lower WSS and higher OSI.
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Affiliation(s)
- Yasuo Takehara
- Department of Fundamental Development for Advanced Low Invasive Diagnostic Imaging, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Haruo Isoda
- Department of Brain & Mind Sciences, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Mamoru Takahashi
- Department of Radiology, Seirei Mikatahara General Hospital, Shizuoka, Japan
| | - Naoki Unno
- Department of Vascular Surgery, Hamamatsu Medical Center, Shizuoka, Japan
| | - Norihiko Shiiya
- First Department of Surgery, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Takasuke Ushio
- Department of Diagnostic Radiology & Nuclear Medicine, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Satoshi Goshima
- Department of Diagnostic Radiology & Nuclear Medicine, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Shinji Naganawa
- Department of Radiology, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Marcus Alley
- Department of Radiology, Stanford University School of Medicine, CA, USA
| | | | - Atsushi Nozaki
- MR Applications and Workflow, GE Healthcare Japan, Tokyo, Japan
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Ding A, Braschkat A, Guber A, Cattaneo G. New Concept of Patient-specific Flow Diversion Treatment of Intracranial Aneurysms : Design Aspects and in vitro Fluid Dynamics. Clin Neuroradiol 2020; 31:671-679. [PMID: 32651611 DOI: 10.1007/s00062-020-00930-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 06/20/2020] [Indexed: 11/29/2022]
Abstract
PURPOSE Current flow diverter (FD) designs limit the possibilities to achieve ideal functional parameters for intra-aneurysmal flow alteration in the implanted state. In this work, we evaluate the technical feasibility of a new patient-specific FD concept and the impact on intra-aneurysmal flow reduction compared to standard FD. METHODS Based on a literature review, we defined functional requirements, followed by the design and manufacturing of two different prototypes, which we implanted in a patient-specific phantom model. Functional porosity distributions and contour parameters were evaluated in the implanted state and compared to standard FD. Subsequently, we carried out a series of particle image velocimetry (PIV) measurements, in order to assess the impact on intra-aneurysmal flow. RESULTS With both patient-specific prototypes, it was possible to achieve stronger intra-aneurysmal flow reductions in terms of maximum and mean velocity and vorticity than a standard FD; however, one design showed a strong sensitivity against malpositioning. Overall, fluid dynamics parameters correlated with geometrical aspects such as the porosity and its grade of homogeneity. Beyond that, we found influences by the FD contour projection within the aneurysm, especially connected to the formation of in-jets. CONCLUSION Our results show that there is a technically feasible concept, which enables a more specific adjustment of functional FD parameters and more effective intra-aneurysmal flow reduction. This could potentially lead to improvements in the efficacy of aneurysm occlusion in cases with challenging fluid dynamics.
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Affiliation(s)
- Andreas Ding
- Acandis GmbH, R&D, Pforzheim, Baden-Württemberg, Germany. .,, Weltzienstr. 24, 76135, Karlsruhe, Germany.
| | | | - Andreas Guber
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Karlsruhe, Baden-Württemberg, Germany
| | - Giorgio Cattaneo
- Institute of Biomedical Engineering, University of Stuttgart, Stuttgart, Baden-Württemberg, Germany
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Li X, Qiao H, Shi Y, Xue J, Bai T, Liu Y, Sun L. Role of proximal and distal tear size ratio in hemodynamic change of acute type A aortic dissection. J Thorac Dis 2020; 12:3200-3210. [PMID: 32642241 PMCID: PMC7330793 DOI: 10.21037/jtd-20-1920] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Background Acute type A aortic dissection (ATAAD) is a life-threatening disease. The aim of this study was to examine the role of tear size in the hemodynamic change and help improve the treatment level of this extremely dangerous disease. Methods A total of 120 ATAAD patients treated in our institution from November 2014 to December 2016 were divided into three groups according to proximal and distal tear size ratio (PDTSR). There were 35 patients in group A (PDTSR ≥2:1), 44 patients in group B (1:2< PDTSR <2:1), and 41 patients in Group C (PDTSR ≤1:2). Three computational fluid dynamics (CFD) models with different PDTSRs were established to investigate the hemodynamic difference in the three groups. Results The mean age (± SD) of the 120 patients included in this study was 47.7±10.1 years. Patients in Group A had a significantly larger proximal tear size (219.1±76.5 vs. 127.7±70.1 vs. 75.7±49.7 mm2; P<0.001). The mortality of the patients in group A was significantly higher than those in group B and group C in the acute phase (37.1% vs. 2.3% vs. 2.4%, respectively; P<0.001). A proximal tear larger than a distal tear was found to be significantly associated with preoperative death in logistic regression analysis (odds ratio: 15.89; 95% confidence interval, 2.702-93.477; P=0.002). Conclusions A proximal tear larger than a distal tear was associated with a significantly high-pressure difference between false and true lumens and more blood flow into the false lumen. In such cases, patients would experience extremely high mortality and morbidity.
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Affiliation(s)
- Xiaonan Li
- Department of Cardiovascular Surgery, Beijing Anzhen Hospital of Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China
| | - Huanyu Qiao
- Department of Cardiovascular Surgery, Beijing Anzhen Hospital of Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China
| | - Yue Shi
- School of Life Science and BioEngineering, Beijing University of Technology, Beijing, China
| | - Jinrong Xue
- Department of Cardiovascular Surgery, Beijing Anzhen Hospital of Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China
| | - Tao Bai
- Department of Cardiovascular Surgery, Beijing Anzhen Hospital of Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China
| | - Yongmin Liu
- Department of Cardiovascular Surgery, Beijing Anzhen Hospital of Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China
| | - Lizhong Sun
- Department of Cardiovascular Surgery, Beijing Anzhen Hospital of Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China
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88
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Cherian J, Dabagh M, Srinivasan VM, Chen S, Johnson J, Wakhloo A, Gupta V, Macho J, Randles A, Kan P. Balloon-Mounted Stents for Treatment of Refractory Flow Diverting Device Wall Malapposition. Oper Neurosurg (Hagerstown) 2020; 19:37-42. [PMID: 31665489 DOI: 10.1093/ons/opz297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Accepted: 07/29/2019] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND As indications for flow diversion (FD) have expanded, new challenges in deployment of flow diverting devices (FDDs) have been encountered. We present 4 cases with aneurysms in which deployment of FDDs were complicated by device malapposition and compromised opening in regions of parent vessel stenosis. In all 4 cases, a balloon-mounted stent was ultimately deployed within the FDD. OBJECTIVE To describe the use of balloon-mounted stents (BMS) within FDDs for correction of flow-limiting stenosis and device malapposition. METHODS Patients undergoing FD for treatment of aneurysms complicated by refractory flow-limiting stenosis were identified through multi-center retrospective review. Those cases requiring use of BMS were identified. Further investigation in one of the cases was performed with a simulated pulsatile blood flow model. RESULTS After attempts to perform balloon angioplasty proved unsuccessful, BMS deployment successfully opened the stenotic parent artery and improved FDD wall apposition in all 4 cases. Simulated pulsatile blood flow modeling confirmed improvements in the distribution of velocity, wall shear stress, oscillatory shear index, and flow pattern structure after stent deployment. One case was complicated by asymptomatic in-stent thrombosis. CONCLUSION In cases of FDD deployment complicated by flow-limiting stenosis refractory to conventional techniques, a BMS deployed within the FD can provide radial support to open both the stenotic device and parent artery. Resulting improvements in device wall apposition may portend greater long-term efficacy of FD. In-stent occlusion can occur and may reflect a thrombogenic interaction between the devices.
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Affiliation(s)
- Jacob Cherian
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, Georgia
| | - Mahsa Dabagh
- Department of Biomedical Engineering, Duke University, Durham, North Carolina
| | | | - Stephen Chen
- Department of Neurosurgery, Baylor College of Medicine, Houston, Texas
| | - Jeremiah Johnson
- Department of Neurosurgery, Baylor College of Medicine, Houston, Texas
| | - Ajay Wakhloo
- Department of Neurointerventional Radiology, Beth Israel Lahey Health, TUFTS University Medical School, Boston, Massachusetts
| | - Vipul Gupta
- Artemis-Agrim Institute of Neurosciences, Artemis Hospital, Gurugram, India
| | - J Macho
- Hospital Clinic de Barcelona, Barcelona, Spain
| | - Amanda Randles
- Department of Biomedical Engineering, Duke University, Durham, North Carolina
| | - Peter Kan
- Department of Neurosurgery, Baylor College of Medicine, Houston, Texas
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89
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Li W, Wang S, Tian Z, Zhu W, Zhang Y, Zhang Y, Wang Y, Wang K, Yang X, Liu J. Discrimination of intracranial aneurysm rupture status: patient-specific inflow boundary may not be a must-have condition in hemodynamic simulations. Neuroradiology 2020; 62:1485-1495. [PMID: 32588092 DOI: 10.1007/s00234-020-02473-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 06/08/2020] [Indexed: 11/26/2022]
Abstract
BACKGROUND Computational fluid dynamics (CFD) are important in evaluating the hemodynamics of intracranial aneurysm rupture, and the setting of inflow boundary conditions is critical. We evaluated intracranial aneurysm hemodynamics based on generalized versus patient-specific inflow boundary conditions to examine the effect of different hemodynamic results on the discrimination of intracranial aneurysm rupture status. METHODS We enrolled 148 patients with 156 intracranial aneurysms. For each included aneurysm, we performed CFD simulation once based on patient-specific and once based on generalized inflow boundary conditions. First, we compared the hemodynamics of intracranial aneurysms based on different inflow boundary conditions. Then, we divided the included aneurysms into a ruptured and unruptured group and compared the hemodynamics between the two groups under patient-specific and generalized inflow boundary conditions. RESULTS For the hemodynamic parameters using specific inflow boundary conditions, more complex flow (p = 0.002), larger minimum WSS (p = 0.024), lower maximum low WSS area (LSA) (p = 0.038), and oscillatory shear index (p = 0.002) were found. Furthermore, we compared the hemodynamics between ruptured and unruptured groups based on different inflow boundary conditions. We found that the significant hemodynamic parameters associated with rupture status were the same, including the proportion of aneurysms with flow complex and unstable flow and the minimum and maximum of LSA (p = 0.011, p = 0.003, p = 0.001 and p = 0.004, respectively). CONCLUSION Patient-specific and generalized inflow boundary conditions of aneurysmal hemodynamics resulted in significant differences. However, the significant parameters associated with rupture status were the same in both conditions, indicating that patient-specific inflow boundary conditions may not be necessary for predicting rupture risk.
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Affiliation(s)
- Wenqiang Li
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, NansanhuanXilu 119, Fengtai District, Beijing, 100070, China
| | - Shengzhang Wang
- Institute of Biomechanics, Department of Aeronautics and Astronautics, Fudan University, Shanghai, China
| | - Zhongbin Tian
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, NansanhuanXilu 119, Fengtai District, Beijing, 100070, China
| | - Wei Zhu
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, NansanhuanXilu 119, Fengtai District, Beijing, 100070, China
| | - Yisen Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, NansanhuanXilu 119, Fengtai District, Beijing, 100070, China
| | - Ying Zhang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, NansanhuanXilu 119, Fengtai District, Beijing, 100070, China
| | - Yang Wang
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang University, Nanchang, China
| | - Kun Wang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, NansanhuanXilu 119, Fengtai District, Beijing, 100070, China
| | - Xinjian Yang
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, NansanhuanXilu 119, Fengtai District, Beijing, 100070, China
| | - Jian Liu
- Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, NansanhuanXilu 119, Fengtai District, Beijing, 100070, China.
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90
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Gottwald LM, Töger J, Markenroth Bloch K, Peper ES, Coolen BF, Strijkers GJ, van Ooij P, Nederveen AJ. High Spatiotemporal Resolution 4D Flow MRI of Intracranial Aneurysms at 7T in 10 Minutes. AJNR Am J Neuroradiol 2020; 41:1201-1208. [PMID: 32586964 DOI: 10.3174/ajnr.a6603] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/21/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND PURPOSE Patients with intracranial aneurysms may benefit from 4D flow MR imaging because the derived wall shear stress is considered a useful marker for risk assessment and growth of aneurysms. However, long scan times limit the clinical implementation of 4D flow MR imaging. Therefore, this study aimed to investigate whether highly accelerated, high resolution, 4D flow MR imaging at 7T provides reliable quantitative blood flow values in intracranial arteries and aneurysms. MATERIALS AND METHODS We used pseudospiral Cartesian undersampling with compressed sensing reconstruction to achieve high spatiotemporal resolution (0.5 mm isotropic, ∼30 ms) in a scan time of 10 minutes. We analyzed the repeatability of accelerated 4D flow scans and compared flow rates, stroke volume, and the pulsatility index with 2D flow and conventional 4D flow MR imaging in a flow phantom and 15 healthy subjects. Additionally, accelerated 4D flow MR imaging with high spatiotemporal resolution was acquired in 5 patients with aneurysms to derive wall shear stress. RESULTS Flow-rate bias compared with 2D flow was lower for accelerated than for conventional 4D flow MR imaging (0.31 ± 0.13, P = .22, versus 0.79 ± 0.17 mL/s, P < .01). Pulsatility index bias gave similar results. Stroke volume bias showed no difference for accelerated as well as for conventional 4D flow compared to 2D flow MR imaging. Repeatability for accelerated 4D flow was similar to that of 2D flow MR imaging. Increased temporal resolution for wall shear stress measurements in 5 intracranial aneurysms did not show a consistent effect for the wall shear stress but did show an effect for the oscillatory shear index. CONCLUSIONS Highly accelerated high spatiotemporal resolution 4D flow MR imaging at 7T in intracranial arteries and aneurysms provides repeatable and accurate quantitative flow values. Flow rate accuracy is significantly increased compared with conventional 4D flow scans.
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Affiliation(s)
- L M Gottwald
- From the Departments of Radiology and Nuclear Medicine (L.M.G., E.S.P., P.v.O., A.J.N.)
| | - J Töger
- Department of Diagnostic Radiology (J.T.), Skane University Hospital, Lund, Sweden
| | - K Markenroth Bloch
- Lund University Bioimaging Center (K.M.B.), Lund University, Lund, Sweden
| | - E S Peper
- From the Departments of Radiology and Nuclear Medicine (L.M.G., E.S.P., P.v.O., A.J.N.)
| | - B F Coolen
- Biomedical Engineering and Physics (B.F.C., G.J.S.), Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands
| | - G J Strijkers
- Biomedical Engineering and Physics (B.F.C., G.J.S.), Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands
| | - P van Ooij
- From the Departments of Radiology and Nuclear Medicine (L.M.G., E.S.P., P.v.O., A.J.N.)
| | - A J Nederveen
- From the Departments of Radiology and Nuclear Medicine (L.M.G., E.S.P., P.v.O., A.J.N.)
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91
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An Automated Workflow for Hemodynamic Computations in Cerebral Aneurysms. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2020; 2020:5954617. [PMID: 32655681 PMCID: PMC7317611 DOI: 10.1155/2020/5954617] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 04/03/2020] [Accepted: 04/28/2020] [Indexed: 01/06/2023]
Abstract
In recent years, computational fluid dynamics (CFD) has become a valuable tool for investigating hemodynamics in cerebral aneurysms. CFD provides flow-related quantities, which have been shown to have a potential impact on aneurysm growth and risk of rupture. However, the adoption of CFD tools in clinical settings is currently limited by the high computational cost and the engineering expertise required for employing these tools, e.g., for mesh generation, appropriate choice of spatial and temporal resolution, and of boundary conditions. Herein, we address these challenges by introducing a practical and robust methodology, focusing on computational performance and minimizing user interaction through automated parameter selection. We propose a fully automated pipeline that covers the steps from a patient-specific anatomical model to results, based on a fast, graphics processing unit- (GPU-) accelerated CFD solver and a parameter selection methodology. We use a reduced order model to compute the initial estimates of the spatial and temporal resolutions and an iterative approach that further adjusts the resolution during the simulation without user interaction. The pipeline and the solver are validated based on previously published results, and by comparing the results obtained for 20 cerebral aneurysm cases with those generated by a state-of-the-art commercial solver (Ansys CFX, Canonsburg PA). The automatically selected spatial and temporal resolutions lead to results which closely agree with the state-of-the-art, with an average relative difference of only 2%. Due to the GPU-based parallelization, simulations are computationally efficient, with a median computation time of 40 minutes per simulation.
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92
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Oka M, Shimo S, Ohno N, Imai H, Abekura Y, Koseki H, Miyata H, Shimizu K, Kushamae M, Ono I, Nozaki K, Kawashima A, Kawamata T, Aoki T. Dedifferentiation of smooth muscle cells in intracranial aneurysms and its potential contribution to the pathogenesis. Sci Rep 2020; 10:8330. [PMID: 32433495 PMCID: PMC7239886 DOI: 10.1038/s41598-020-65361-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 05/04/2020] [Indexed: 12/18/2022] Open
Abstract
Smooth muscle cells (SMCs) are the major type of cells constituting arterial walls and play a role to maintain stiffness via producing extracellular matrix. Here, the loss and degenerative changes of SMCs become the major histopathological features of an intracranial aneurysm (IA), a major cause of subarachnoid hemorrhage. Considering the important role of SMCs and the loss of this type of cells in IA lesions, we in the present study subjected rats to IA models and examined how SMCs behave during disease progression. We found that, at the neck portion of IAs, SMCs accumulated underneath the internal elastic lamina according to disease progression and formed the intimal hyperplasia. As these SMCs were positive for a dedifferentiation marker, myosin heavy chain 10, and contained abundant mitochondria and rough endoplasmic reticulum, SMCs at the intimal hyperplasia were dedifferentiated and activated. Furthermore, dedifferentiated SMCs expressed some pro-inflammatory factors, suggesting the role in the formation of inflammatory microenvironment to promote the disease. Intriguingly, some SMCs at the intimal hyperplasia were positive for CD68 and contained lipid depositions, indicating similarity with atherosclerosis. We next examined a potential factor mediating dedifferentiation and recruitment of SMCs. Platelet derived growth factor (PDGF)-BB was expressed in endothelial cells at the neck portion of lesions where high wall shear stress (WSS) was loaded. PDGF-BB facilitated migration of SMCs across matrigel-coated pores in a transwell system, promoted dedifferentiation of SMCs and induced expression of pro-inflammatory genes in these cells in vitro. Because, in a stenosis model of rats, PDGF-BB expression was expressed in endothelial cells loaded in high WSS regions, and SMCs present nearby were dedifferentiated, hence a correlation existed between high WSS, PDGFB and dedifferentiation in vivo. In conclusion, dedifferentiated SMCs presumably by PDGF-BB produced from high WSS-loaded endothelial cells accumulate in the intimal hyperplasia to form inflammatory microenvironment leading to the progression of the disease.
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Affiliation(s)
- Mieko Oka
- Department of Molecular Pharmacology, Research Institute, National Cerebral and Cardiovascular Center, 6-1 Kishibeshinmachi, Suita City, Osaka, 564-8565, Japan.,Core Research for Evolutional Science and Technology from Japan Agency for Medical Research and Development, National Cerebral and Cardiovascular Center, 6-1 Kishibeshinmachi, Suita City, Osaka, 564-8565, Japan.,Department of Neurosurgery, Tokyo Women's Medical University, 8-1 Kawata-cho, Shinjyuku-ku, Tokyo, 162-8666, Japan
| | - Satoshi Shimo
- Department of Occupational Therapy, Health Science University, 7181 Kodachi, Minamitsurugun Fujikawaguchikomachi, Yamanashi, 401-0380, Japan
| | - Nobuhiko Ohno
- Division of Histology and Cell Biology, Department of Anatomy, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke City, Tochigi, 329-0498, Japan.,Division of Ultrastructural Research, National Institute for Physiological Sciences, 38 Saigonaka, Meidaiji-cho, Okazaki City, Aichi, 444-8787, Japan
| | - Hirohiko Imai
- Department of Systems Science, Graduate School of Informatics, Kyoto University, 36-1 Yoshidahomachi Saikyo-ku, Kyoto City, Kyoto, 606-8317, Japan
| | - Yu Abekura
- Department of Molecular Pharmacology, Research Institute, National Cerebral and Cardiovascular Center, 6-1 Kishibeshinmachi, Suita City, Osaka, 564-8565, Japan.,Core Research for Evolutional Science and Technology from Japan Agency for Medical Research and Development, National Cerebral and Cardiovascular Center, 6-1 Kishibeshinmachi, Suita City, Osaka, 564-8565, Japan.,Department of Neurosurgery, Kyoto University Graduate School of Medicine, 54 Kawahara-cho Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Hirokazu Koseki
- Department of Molecular Pharmacology, Research Institute, National Cerebral and Cardiovascular Center, 6-1 Kishibeshinmachi, Suita City, Osaka, 564-8565, Japan.,Core Research for Evolutional Science and Technology from Japan Agency for Medical Research and Development, National Cerebral and Cardiovascular Center, 6-1 Kishibeshinmachi, Suita City, Osaka, 564-8565, Japan.,Department of Neurosurgery, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo, 105-8461, Japan
| | - Haruka Miyata
- Department of Molecular Pharmacology, Research Institute, National Cerebral and Cardiovascular Center, 6-1 Kishibeshinmachi, Suita City, Osaka, 564-8565, Japan.,Core Research for Evolutional Science and Technology from Japan Agency for Medical Research and Development, National Cerebral and Cardiovascular Center, 6-1 Kishibeshinmachi, Suita City, Osaka, 564-8565, Japan.,Department of Neurosurgery, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu City, Shiga, 520-2192, Japan
| | - Kampei Shimizu
- Department of Molecular Pharmacology, Research Institute, National Cerebral and Cardiovascular Center, 6-1 Kishibeshinmachi, Suita City, Osaka, 564-8565, Japan.,Core Research for Evolutional Science and Technology from Japan Agency for Medical Research and Development, National Cerebral and Cardiovascular Center, 6-1 Kishibeshinmachi, Suita City, Osaka, 564-8565, Japan.,Department of Neurosurgery, Kyoto University Graduate School of Medicine, 54 Kawahara-cho Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Mika Kushamae
- Department of Molecular Pharmacology, Research Institute, National Cerebral and Cardiovascular Center, 6-1 Kishibeshinmachi, Suita City, Osaka, 564-8565, Japan.,Core Research for Evolutional Science and Technology from Japan Agency for Medical Research and Development, National Cerebral and Cardiovascular Center, 6-1 Kishibeshinmachi, Suita City, Osaka, 564-8565, Japan.,Department of Neurosurgery, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8666, Japan
| | - Isao Ono
- Department of Molecular Pharmacology, Research Institute, National Cerebral and Cardiovascular Center, 6-1 Kishibeshinmachi, Suita City, Osaka, 564-8565, Japan.,Core Research for Evolutional Science and Technology from Japan Agency for Medical Research and Development, National Cerebral and Cardiovascular Center, 6-1 Kishibeshinmachi, Suita City, Osaka, 564-8565, Japan.,Department of Neurosurgery, Kyoto University Graduate School of Medicine, 54 Kawahara-cho Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Kazuhiko Nozaki
- Department of Neurosurgery, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu City, Shiga, 520-2192, Japan
| | - Akitsugu Kawashima
- Department of Neurosurgery, Tokyo Women's Medical University Yachiyo Medical Center, 477-96 Oowadashinden, Yachiyo City, Chiba, 276-8524, Japan
| | - Takakazu Kawamata
- Department of Neurosurgery, Tokyo Women's Medical University, 8-1 Kawata-cho, Shinjyuku-ku, Tokyo, 162-8666, Japan
| | - Tomohiro Aoki
- Department of Molecular Pharmacology, Research Institute, National Cerebral and Cardiovascular Center, 6-1 Kishibeshinmachi, Suita City, Osaka, 564-8565, Japan. .,Core Research for Evolutional Science and Technology from Japan Agency for Medical Research and Development, National Cerebral and Cardiovascular Center, 6-1 Kishibeshinmachi, Suita City, Osaka, 564-8565, Japan.
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93
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Lipp SN, Niedert EE, Cebull HL, Diorio TC, Ma JL, Rothenberger SM, Stevens Boster KA, Goergen CJ. Computational Hemodynamic Modeling of Arterial Aneurysms: A Mini-Review. Front Physiol 2020; 11:454. [PMID: 32477163 PMCID: PMC7235429 DOI: 10.3389/fphys.2020.00454] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 04/09/2020] [Indexed: 01/02/2023] Open
Abstract
Arterial aneurysms are pathological dilations of blood vessels, which can be of clinical concern due to thrombosis, dissection, or rupture. Aneurysms can form throughout the arterial system, including intracranial, thoracic, abdominal, visceral, peripheral, or coronary arteries. Currently, aneurysm diameter and expansion rates are the most commonly used metrics to assess rupture risk. Surgical or endovascular interventions are clinical treatment options, but are invasive and associated with risk for the patient. For aneurysms in locations where thrombosis is the primary concern, diameter is also used to determine the level of therapeutic anticoagulation, a treatment that increases the possibility of internal bleeding. Since simple diameter is often insufficient to reliably determine rupture and thrombosis risk, computational hemodynamic simulations are being developed to help assess when an intervention is warranted. Created from subject-specific data, computational models have the potential to be used to predict growth, dissection, rupture, and thrombus-formation risk based on hemodynamic parameters, including wall shear stress, oscillatory shear index, residence time, and anomalous blood flow patterns. Generally, endothelial damage and flow stagnation within aneurysms can lead to coagulation, inflammation, and the release of proteases, which alter extracellular matrix composition, increasing risk of rupture. In this review, we highlight recent work that investigates aneurysm geometry, model parameter assumptions, and other specific considerations that influence computational aneurysm simulations. By highlighting modeling validation and verification approaches, we hope to inspire future computational efforts aimed at improving our understanding of aneurysm pathology and treatment risk stratification.
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Affiliation(s)
- Sarah N Lipp
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
| | - Elizabeth E Niedert
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
| | - Hannah L Cebull
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
| | - Tyler C Diorio
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
| | - Jessica L Ma
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
| | - Sean M Rothenberger
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
| | - Kimberly A Stevens Boster
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States.,School of Mechanical Engineering, Purdue University, West Lafayette, IN, United States
| | - Craig J Goergen
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
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94
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Saqr KM, Rashad S, Tupin S, Niizuma K, Hassan T, Tominaga T, Ohta M. What does computational fluid dynamics tell us about intracranial aneurysms? A meta-analysis and critical review. J Cereb Blood Flow Metab 2020; 40:1021-1039. [PMID: 31213162 PMCID: PMC7181089 DOI: 10.1177/0271678x19854640] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Despite the plethora of published studies on intracranial aneurysms (IAs) hemodynamic using computational fluid dynamics (CFD), limited progress has been made towards understanding the complex physics and biology underlying IA pathophysiology. Guided by 1733 published papers, we review and discuss the contemporary IA hemodynamics paradigm established through two decades of IA CFD simulations. We have traced the historical origins of simplified CFD models which impede the progress of comprehending IA pathology. We also delve into the debate concerning the Newtonian fluid assumption used to represent blood flow computationally. We evidently demonstrate that the Newtonian assumption, used in almost 90% of studies, might be insufficient to describe IA hemodynamics. In addition, some fundamental properties of the Navier-Stokes equation are revisited in supplementary material to highlight some widely spread misconceptions regarding wall shear stress (WSS) and its derivatives. Conclusively, our study draws a roadmap for next-generation IA CFD models to help researchers investigate the pathophysiology of IAs.
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Affiliation(s)
- Khalid M Saqr
- Biomedical Flow Dynamics Laboratory, Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan.,Department of Mechanical Engineering, College of Engineering and Technology, Arab Academy for Science, Technology and Maritime Transport, Alexandria, Egypt
| | - Sherif Rashad
- Department of Neurosurgical Engineering and Translational Neuroscience, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.,Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Simon Tupin
- Biomedical Flow Dynamics Laboratory, Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan
| | - Kuniyasu Niizuma
- Department of Neurosurgical Engineering and Translational Neuroscience, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.,Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.,Department of Neurosurgical Engineering and Translational Neuroscience, Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan
| | - Tamer Hassan
- Department of Neurosurgery, Alexandria University School of Medicine, Azarita Medical Campus, Alexandria, Egypt
| | - Teiji Tominaga
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Makoto Ohta
- Biomedical Flow Dynamics Laboratory, Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan
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95
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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.
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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
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96
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Rayz VL, Cohen-Gadol AA. Hemodynamics of Cerebral Aneurysms: Connecting Medical Imaging and Biomechanical Analysis. Annu Rev Biomed Eng 2020; 22:231-256. [PMID: 32212833 DOI: 10.1146/annurev-bioeng-092419-061429] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In the last two decades, numerous studies have conducted patient-specific computations of blood flow dynamics in cerebral aneurysms and reported correlations between various hemodynamic metrics and aneurysmal disease progression or treatment outcomes. Nevertheless, intra-aneurysmal flow analysis has not been adopted in current clinical practice, and hemodynamic factors usually are not considered in clinical decision making. This review presents the state of the art in cerebral aneurysm imaging and image-based modeling, discussing the advantages and limitations of each approach and focusing on the translational value of hemodynamic analysis. Combining imaging and modeling data obtained from different flow modalities can improve the accuracy and fidelity of resulting velocity fields and flow-derived factors that are thought to affect aneurysmal disease progression. It is expected that predictive models utilizing hemodynamic factors in combination with patient medical history and morphological data will outperform current risk scores and treatment guidelines. Possible future directions include novel approaches enabling data assimilation and multimodality analysis of cerebral aneurysm hemodynamics.
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Affiliation(s)
- Vitaliy L Rayz
- Weldon School of Biomedical Engineering and School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, USA;
| | - Aaron A Cohen-Gadol
- Department of Neurosurgery, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.,Goodman Campbell Brain and Spine, Carmel, Indiana 46032, USA
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97
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A Hypothetical Vascular Stent with Locally Enlarged Segment and the Hemodynamic Evaluation. Cardiol Res Pract 2020; 2020:7041284. [PMID: 32185077 PMCID: PMC7060871 DOI: 10.1155/2020/7041284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 02/03/2020] [Indexed: 11/17/2022] Open
Abstract
Among the interventional stenting methods for treating coronary bifurcation lesions, the conventional treatments still have disadvantages, which include increased intervention difficulties or inadequate supply of blood flow to side branches and may alter the physiological function of downstream organs. Thus, the optimized design of stent geometry needs to be improved based on the specific shape of branches to minimize the complications of inadequate blood flow to the downstream organs and tissues. Our research used 3D modeling and fluid dynamics simulation to design and evaluate a new stent with locally enlarged segment by altering the proportion and length of enlarged surface area based on Bernoulli's equation. The aim is to increase the pressure and blood flow supply at side branches. According to series of blood flow simulations, the stent with 10% enlargement of surface area and length of 3 folders of stent diameter was assigned as the optimized design. The results revealed that by using this design, according to the simulation results, the average pressure on side branches increased at the rate of 43.6%, which would contribute to the adequate blood supply to the downstream organs. Besides, the average wall shear stress (WSS) at sidewalls increased at 9.2% while the average WSS on the host artery wall decreased at 14.1%. There is in the absent of noticeable rise in the total area of low WSS that blows the threshold of 0.5 Pa. Therefore, the present study provides a new method to optimize the hemodynamics features of stent for bifurcation arteries.
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98
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Oliveira REMD, Costa HDS, Araújo Júnior HND, Lopes IRG, Lopes PMA, Gurgel JVDO, de Oliveira MF. Collateral arteries of the aortic arch of the red-rumped agouti (Dasyprocta leporina Linnaeus, 1758). Anat Histol Embryol 2020; 49:417-424. [PMID: 32112454 DOI: 10.1111/ahe.12544] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 01/29/2020] [Accepted: 02/05/2020] [Indexed: 11/29/2022]
Abstract
Detailed knowledge of the arterial system is an important prerequisite when interpreting experimental data in research, as well as in the diagnosis of cardiovascular disease using imaging techniques such as Doppler echocardiography and contrast radiography. Thus, considering the importance of the aortic arrangement, the objective of this study was to describe the collateral arteries of the aortic arch of agoutis in order to establish the standard model, and therefore contribute to studies involving research related to heart disease, and produce information for a more accurate diagnosis in complementary imaging examinations. In this study, 14 adult animals were used, comprising eight males and six females. The vascular system was washed with 0.9% aqueous saline solution and perfused with Neoprene 450 latex coloured with yellow or red pigment, which was subsequently dissected and analysed. One male animal was used for the digital contrast radiography technique perfused with a liquid barium sulphate solution (Bariogel® ) (1 g/ml) and Neoprene 450 latex, both diluted 1/3. The aortic arch of the agouti presented with only the brachiocephalic trunk as collateral branch in all the animals studied. Thus, agouti falls into type 1 for mammalian aortic arch vascular arrangements.
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Affiliation(s)
- Radan Elvis Matias de Oliveira
- Department of Animal Sciences, Applied Animal Morphophysiology Laboratory - LABMORFA, Federal Rural University of Semi-Árido - UFERSA, Mossoró, Brazil.,Department of Morphology - DMOR, Bioscience Center - CB, Federal University of Rio Grande do Norte - UFRN, Natal, Brazil
| | - Herson da Silva Costa
- Department of Animal Sciences, Applied Animal Morphophysiology Laboratory - LABMORFA, Federal Rural University of Semi-Árido - UFERSA, Mossoró, Brazil
| | - Hélio Noberto de Araújo Júnior
- Department of Animal Sciences, Applied Animal Morphophysiology Laboratory - LABMORFA, Federal Rural University of Semi-Árido - UFERSA, Mossoró, Brazil
| | - Igor Renno Guimarães Lopes
- Department of Animal Sciences, Applied Animal Morphophysiology Laboratory - LABMORFA, Federal Rural University of Semi-Árido - UFERSA, Mossoró, Brazil
| | - Paulo Mateus Alves Lopes
- Department of Animal Sciences, Applied Animal Morphophysiology Laboratory - LABMORFA, Federal Rural University of Semi-Árido - UFERSA, Mossoró, Brazil
| | - João Vitor de Oliveira Gurgel
- Department of Animal Sciences, Applied Animal Morphophysiology Laboratory - LABMORFA, Federal Rural University of Semi-Árido - UFERSA, Mossoró, Brazil
| | - Moacir Franco de Oliveira
- Department of Animal Sciences, Applied Animal Morphophysiology Laboratory - LABMORFA, Federal Rural University of Semi-Árido - UFERSA, Mossoró, Brazil
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99
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Size-Dependent Distribution of Patient-Specific Hemodynamic Factors in Unruptured Cerebral Aneurysms Using Computational Fluid Dynamics. Diagnostics (Basel) 2020; 10:diagnostics10020064. [PMID: 31991621 PMCID: PMC7168895 DOI: 10.3390/diagnostics10020064] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/17/2020] [Accepted: 01/23/2020] [Indexed: 12/26/2022] Open
Abstract
PURPOSE To analyze size-dependent hemodynamic factors [velocity, shear rate, blood viscosity, wall shear stress (WSS)] in unruptured cerebral aneurysms using computational fluid dynamics (CFD) based on the measured non-Newtonian model of viscosity. METHODS Twenty-one patients with unruptured aneurysms formed the study cohort. Patient-specific geometric models were reconstructed for CFD analyses. Aneurysms were divided into small and large groups based on a cutoff size of 5 mm. For comparison between small and large aneurysms, 5 morphologic variables were measured. Patient-specific non-Newtonian blood viscosity was applied for more detailed CFD simulation. Quantitative and qualitative analyses of velocity, shear rate, blood viscosity, and WSS were conducted to compare small and large aneurysms. RESULTS Complex flow patterns were found in large aneurysms. Large aneurysms had a significantly lower shear rate (235 ± 341 s-1)) than small aneurysms (915 ± 432 s-1) at peak-systole. Two times higher blood viscosity was observed in large aneurysms compared with small aneurysms. Lower WSS was found in large aneurysms (1.38 ± 1.36 Pa) than in small aneurysms (3.53 ± 1.22 Pa). All the differences in hemodynamic factors between small and large aneurysms were statistically significant. CONCLUSIONS Large aneurysms tended to have complex flow patterns, low shear rate, high blood viscosity, and low WSS. The hemodynamic factors that we analyzed might be useful for decision making before surgical treatment of aneurysms.
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100
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Wan H, Huang L, Ge L, Jiang Y, Li G, Leng X, Feng X, Xiang J, Zhang X. Are hemodynamics of irregular small carotid-ophthalmic aneurysms different from those of regular ones and large aneurysms based on numerical simulation? Neuroradiology 2020; 62:511-518. [PMID: 31925470 DOI: 10.1007/s00234-019-02348-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 12/11/2019] [Indexed: 10/25/2022]
Abstract
PURPOSE The purpose of this study is to investigate whether hemodynamics of unruptured, irregular small intracranial aneurysms (SIAs) are different from those of regular ones and large intracranial aneurysms (LIAs) in ophthalmic artery segment of internal carotid artery (ICA). METHODS Between April 2015 and June 2018, 106 carotid-ophthalmic artery aneurysms were retrospectively analyzed using 3D angiographic images and computational fluid dynamics (CFD). Three categories were stratified: regular SIAs, irregular SIAs and LIAs. Statistical comparisons of the differences in clinical, morphological and hemodynamic parameters among regular SIA, irregular SIA and LIA groups were performed by one-way analysis of variance (ANOVA) or Kruskal-Wallis Test. RESULTS The median maximal height of regular SIA, irregular SIA and LIA were 3.03 (interquartile range: 2.49-4.22) mm, 4.59 (interquartile range: 3.86-5.32) mm and 11.06 (interquartile range: 9.28-13.69) mm, all P < 0.05). Low shear-stress area percentage (LSA%) and oscillatory shear index (OSI) of irregular SIAs and LIAs were not significantly different (P = 0.72, P = 0.27 respectively), and were significantly higher than those of regular SIAs (all P < 0.01). Wall shear stress (WSS) and normalized wall shear stress (NWSS) of irregular SIAs were significantly higher than those of LIAs (P < 0.01, P < 0.01 respectively), but lower than those of regular SIAs (P < 0.01, P < 0.01 respectively). CONCLUSIONS Special unruptured irregular SIAs share a similarity of hemodynamic characteristics with LIAs in high LSA% and high OSI, and are different from regular SIAs in hemodynamics.
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Affiliation(s)
- Hailin Wan
- Department of Radiology, Huashan Hospital, Fudan University, No. 12 Middle Wulumuqi Road, Shanghai, 200040, China
| | - Lei Huang
- Department of Radiology, Huashan Hospital, Fudan University, No. 12 Middle Wulumuqi Road, Shanghai, 200040, China
| | - Liang Ge
- Department of Radiology, Huashan Hospital, Fudan University, No. 12 Middle Wulumuqi Road, Shanghai, 200040, China
| | - Yeqing Jiang
- Department of Radiology, Huashan Hospital, Fudan University, No. 12 Middle Wulumuqi Road, Shanghai, 200040, China
| | - Gaohui Li
- ArteryFlow Technology Co., Ltd, 459 Qianmo Road, Hangzhou, 310051, China
| | - Xiaochang Leng
- ArteryFlow Technology Co., Ltd, 459 Qianmo Road, Hangzhou, 310051, China
| | - Xiaoyuan Feng
- Department of Radiology, Huashan Hospital, Fudan University, No. 12 Middle Wulumuqi Road, Shanghai, 200040, China
| | - Jianping Xiang
- ArteryFlow Technology Co., Ltd, 459 Qianmo Road, Hangzhou, 310051, China
| | - Xiaolong Zhang
- Department of Radiology, Huashan Hospital, Fudan University, No. 12 Middle Wulumuqi Road, Shanghai, 200040, China.
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