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Shimodoumae R, Tanaka G, Yamaguchi R, Ohta M. Numerical simulation of flow behavior in basilar bifurcation computed tomography angiography. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2024; 40:e3805. [PMID: 38296338 DOI: 10.1002/cnm.3805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 11/20/2023] [Accepted: 01/14/2024] [Indexed: 04/05/2024]
Abstract
In this study, a moving boundary deformation model based on four-dimensional computed tomography angiography (4D-CTA) with high temporal resolution is constructed, and blood flow dynamics of cerebral aneurysms are investigated by numerical simulation. A realistic moving boundary deformation model of a cerebral aneurysm was constructed based on 4D-CTA in each phase. Four hemodynamic factors (wall shear stress [WSS], wall shear stress divergence [WSSD], oscillatory shear index [OSI], and residual residence time [RRT]) were obtained from numerical simulations, and these factors were evaluated in basilar artery aneurysms. Comparison of the rigid body condition and the moving boundary condition investigating the relationship between wall displacement and hemodynamic factors clarified that the spatial-averaged WSS and maximum WSSD considering only the aneurysmal dome has a large difference between conditions during the peak systole, and there were also significant differences in OSI and RRT.
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Affiliation(s)
- Ryo Shimodoumae
- Chiba University Graduate School of Science and Engineering, Chiba, Japan
| | - Gaku Tanaka
- Chiba University Graduate School of Science and Engineering, Chiba, Japan
| | - Ryuhei Yamaguchi
- Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan
| | - Makoto Ohta
- Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan
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Xin S, Chen Y, Zhao B, Liang F. Combination of Morphological and Hemodynamic Parameters for Assessing the Rupture Risk of Intracranial Aneurysms: a Retrospective Study On Mirror Middle Cerebral Artery Aneurysms. J Biomech Eng 2022; 144:1135619. [PMID: 35147191 DOI: 10.1115/1.4053793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Indexed: 11/08/2022]
Abstract
Discordant findings were frequently reported by studies dedicated to exploring the association of morphological/hemodynamic factors with the rupture of intracranial aneurysms (IAs), probably owing to insufficient control of confounding factors. In this study, we aimed to minimize the influences of confounding factors by focusing IAs of interest on mirror aneurysms and, meanwhile, modeling IAs together with the cerebral arterial network to improve the physiological fidelity of hemodynamic simulation. 52 mirror aneurysms located at the middle cerebral artery (MCA) in 26 patients were retrospectively investigated. Numerical tests performed on two randomly selected patients demonstrated that over truncation of cerebral arteries proximal to the MCA during image-based model reconstruction led to uncertain changes in computed values of intra-aneurysmal hemodynamic parameters, which justified the minimal truncation strategy adopted in our study. Five morphological parameters (i.e., volume (V), height (H), dome area (DA), non-sphericity index (NSI), and size ratio (SR)) and two hemodynamic parameters (i.e., peak WSS (peakWSS), and pressure loss coefficient (PLc)) were found to differ significantly between the ruptured and unruptured aneurysms and proved by receiver operating characteristic (ROC) analysis to have potential value for differentiating the rupture status of aneurysm with the areas under curve (AUCs) ranging from 0.681 to 0.763. Integrating V, SR, peakWSS and PLc or some of them into regression models considerably improved the classification of aneurysms, elevating AUC up to 0.864, which indicates that morphological and hemodynamic parameters have complementary roles in assessing the risk of aneurysm rupture.
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Affiliation(s)
- Shangzhe Xin
- State Key Laboratory of Ocean Engineering, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yongchun Chen
- Department of Radiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, Zhejiang
| | - Bing Zhao
- Department of Neurosurgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China
| | - Fuyou Liang
- State Key Laboratory of Ocean Engineering, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
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Ivantsits M, Goubergrits L, Kuhnigk JM, Huellebrand M, Bruening J, Kossen T, Pfahringer B, Schaller J, Spuler A, Kuehne T, Jia Y, Li X, Shit S, Menze B, Su Z, Ma J, Nie Z, Jain K, Liu Y, Lin Y, Hennemuth A. Detection and analysis of cerebral aneurysms based on X-ray rotational angiography - the CADA 2020 challenge. Med Image Anal 2021; 77:102333. [PMID: 34998111 DOI: 10.1016/j.media.2021.102333] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 10/12/2021] [Accepted: 12/07/2021] [Indexed: 01/10/2023]
Abstract
The Cerebral Aneurysm Detection and Analysis (CADA) challenge was organized to support the development and benchmarking of algorithms for detecting, analyzing, and risk assessment of cerebral aneurysms in X-ray rotational angiography (3DRA) images. 109 anonymized 3DRA datasets were provided for training, and 22 additional datasets were used to test the algorithmic solutions. Cerebral aneurysm detection was assessed using the F2 score based on recall and precision, and the fit of the delivered bounding box was assessed using the distance to the aneurysm. The segmentation quality was measured using the Jaccard index and a combination of different surface distance measures. Systematic errors were analyzed using volume correlation and bias. Rupture risk assessment was evaluated using the F2 score. 158 participants from 22 countries registered for the CADA challenge. The U-Net-based detection solutions presented by the community show similar accuracy compared to experts (F2 score 0.92), with a small number of missed aneurysms with diameters smaller than 3.5 mm. In addition, the delineation of these structures, based on U-Net variations, is excellent, with a Jaccard score of 0.92. The rupture risk estimation methods achieved an F2 score of 0.71. The performance of the detection and segmentation solutions is equivalent to that of human experts. The best results are obtained in rupture risk estimation by combining different image-based, morphological, and computational fluid dynamic parameters using machine learning methods. Furthermore, we evaluated the best methods pipeline, from detecting and delineating the vessel dilations to estimating the risk of rupture. The chain of these methods achieves an F2-score of 0.70, which is comparable to applying the risk prediction to the ground-truth delineation (0.71).
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Affiliation(s)
- Matthias Ivantsits
- Charit Universittsmedizin Berlin, Augustenburger Pl. 1, Berlin 13353, Germany.
| | - Leonid Goubergrits
- Charit Universittsmedizin Berlin, Augustenburger Pl. 1, Berlin 13353, Germany; Einstein Center Digital Future, Wilhelmstrae 67, Berlin 10117, Germany
| | | | - Markus Huellebrand
- Charit Universittsmedizin Berlin, Augustenburger Pl. 1, Berlin 13353, Germany; Fraunhofer MEVIS, Am Fallturm 1, Bremen 28359, Germany
| | - Jan Bruening
- Charit Universittsmedizin Berlin, Augustenburger Pl. 1, Berlin 13353, Germany
| | - Tabea Kossen
- Charit Universittsmedizin Berlin, Augustenburger Pl. 1, Berlin 13353, Germany
| | - Boris Pfahringer
- Charit Universittsmedizin Berlin, Augustenburger Pl. 1, Berlin 13353, Germany
| | - Jens Schaller
- Charit Universittsmedizin Berlin, Augustenburger Pl. 1, Berlin 13353, Germany
| | - Andreas Spuler
- Helios Hospital Berlin-Buch, Schwanebecker Chaussee 50, Berlin 13125, Germany
| | - Titus Kuehne
- Charit Universittsmedizin Berlin, Augustenburger Pl. 1, Berlin 13353, Germany; German Heart Centre Berlin, Augustenburger Pl. 1, Berlin 13353, Germany; DZHK (German Centre for Cardiovascular Research), Berlin, Germany
| | - Yizhuan Jia
- Mediclouds Medical Technology, Beijing, China
| | - Xuesong Li
- School of Computer Science and Technology, Beijing Institute of Technology, Beijing, China
| | - Suprosanna Shit
- Departments of Informatics, Technical University Munich, Germany; TranslaTUM Center for Translational Cancer Research, Munich, Germany
| | - Bjoern Menze
- Departments of Informatics, Technical University Munich, Germany; TranslaTUM Center for Translational Cancer Research, Munich, Germany; Department of Quantitative Biomedicine of UZH, Zurich, Switzerland
| | - Ziyu Su
- School of Computer Science and Technology, Beijing Institute of Technology, Beijing, China
| | - Jun Ma
- Department of Mathematics, Nanjing University of Science and Technology, Nanjing, China
| | - Ziwei Nie
- Department of Mathematics, Nanjing University, Nanjing, China
| | - Kartik Jain
- Faculty of Engineering Technology, University of Twente, P.O. Box 217, Enschede 7500, AE, the Netherlands
| | - Yanfei Liu
- Jarvis Lab, Tencent, Shenzhen, China; Shenzhen United Imaging Research Institute of Innovative Medical Equipment Innovation Research, Shenzhen, China
| | - Yi Lin
- Jarvis Lab, Tencent, Shenzhen, China
| | - Anja Hennemuth
- Charit Universittsmedizin Berlin, Augustenburger Pl. 1, Berlin 13353, Germany; Fraunhofer MEVIS, Am Fallturm 1, Bremen 28359, Germany; German Heart Centre Berlin, Augustenburger Pl. 1, Berlin 13353, Germany; DZHK (German Centre for Cardiovascular Research), Berlin, Germany
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Shi Z, Chen GZ, Mao L, Li XL, Zhou CS, Xia S, Zhang YX, Zhang B, Hu B, Lu GM, Zhang LJ. Machine Learning-Based Prediction of Small Intracranial Aneurysm Rupture Status Using CTA-Derived Hemodynamics: A Multicenter Study. AJNR Am J Neuroradiol 2021; 42:648-654. [PMID: 33664115 PMCID: PMC8041003 DOI: 10.3174/ajnr.a7034] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 11/09/2020] [Indexed: 01/08/2023]
Abstract
BACKGROUND AND PURPOSE Small intracranial aneurysms are being increasingly detected while the rupture risk is not well-understood. We aimed to develop rupture-risk models of small aneurysms by combining clinical, morphologic, and hemodynamic information based on machine learning techniques and to test the models in external validation datasets. MATERIALS AND METHODS From January 2010 to December 2016, five hundred four consecutive patients with only small aneurysms (<5 mm) detected by CTA and invasive cerebral angiography (or surgery) were retrospectively enrolled and randomly split into training (81%) and internal validation (19%) sets to derive and validate the proposed machine learning models (support vector machine, random forest, logistic regression, and multilayer perceptron). Hemodynamic parameters were obtained using computational fluid dynamics simulation. External validation was performed in other hospitals to test the models. RESULTS The support vector machine performed the best with areas under the curve of 0.88 (95% CI, 0.85-0.92) and 0.91 (95% CI, 0.74-0.98) in the training and internal validation datasets, respectively. Feature ranks suggested hemodynamic parameters, including stable flow pattern, concentrated inflow streams, and a small (<50%) flow-impingement zone, and the oscillatory shear index coefficient of variation, were the best predictors of aneurysm rupture. The support vector machine showed an area under the curve of 0.82 (95% CI, 0.69-0.94) in the external validation dataset, and no significant difference was found for the areas under the curve between internal and external validation datasets (P = .21). CONCLUSIONS This study revealed that machine learning had a good performance in predicting the rupture status of small aneurysms in both internal and external datasets. Aneurysm hemodynamic parameters were regarded as the most important predictors.
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Affiliation(s)
- Z Shi
- From the Department of Diagnostic Radiology (Z.S., C.S.Z., B.H., G.M.L., L.J.Z.), Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - G Z Chen
- Department of Medical Imaging (G.Z.C.), Nanjing First Hospital, Nanjing, Jiangsu, China
| | - L Mao
- Deepwise AI Lab (L.M., X.L.L.), Beijing, China
| | - X L Li
- Deepwise AI Lab (L.M., X.L.L.), Beijing, China
| | - C S Zhou
- From the Department of Diagnostic Radiology (Z.S., C.S.Z., B.H., G.M.L., L.J.Z.), Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - S Xia
- Department of Radiology (S.X.), Tianjin First Central Hospital, Tianjin, China
| | - Y X Zhang
- Laboratory of Image Science and Technology (Y.X.Z.), School of Computer Science and Engineering, Southeast University, Nanjing, China
| | - B Zhang
- Department of Radiology (B.Z.), Taizhou People's Hospital, Taizhou, Jiangsu, China
| | - B Hu
- From the Department of Diagnostic Radiology (Z.S., C.S.Z., B.H., G.M.L., L.J.Z.), Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - G M Lu
- From the Department of Diagnostic Radiology (Z.S., C.S.Z., B.H., G.M.L., L.J.Z.), Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - L J Zhang
- From the Department of Diagnostic Radiology (Z.S., C.S.Z., B.H., G.M.L., L.J.Z.), Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
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Han P, Jin D, Wei W, Song C, Leng X, Liu L, Yu J, Li X. The prognostic effects of hemodynamic parameters on rupture of intracranial aneurysm: A systematic review and meta-analysis. Int J Surg 2021; 86:15-23. [DOI: 10.1016/j.ijsu.2020.12.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/13/2020] [Accepted: 12/28/2020] [Indexed: 12/26/2022]
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6
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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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Mazzi V, Gallo D, Calò K, Najafi M, Khan MO, De Nisco G, Steinman DA, Morbiducci U. A Eulerian method to analyze wall shear stress fixed points and manifolds in cardiovascular flows. Biomech Model Mechanobiol 2019; 19:1403-1423. [PMID: 31865482 DOI: 10.1007/s10237-019-01278-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 12/08/2019] [Indexed: 12/12/2022]
Abstract
Based upon dynamical systems theory, a fixed point of a vector field such as the wall shear stress (WSS) at the luminal surface of a vessel is a point where the vector field vanishes. Unstable/stable manifolds identify contraction/expansion regions linking fixed points. The significance of such WSS topological features lies in their strong link with "disturbed" flow features like flow stagnation, separation and reversal, deemed responsible for vascular dysfunction initiation and progression. Here, we present a Eulerian method to analyze WSS topological skeleton through the identification and classification of WSS fixed points and manifolds in complex vascular geometries. The method rests on the volume contraction theory and analyzes the WSS topological skeleton through the WSS vector field divergence and Poincar[Formula: see text] index. The method is here applied to computational hemodynamics models of carotid bifurcation and intracranial aneurysm. An in-depth analysis of the time dependence of the WSS topological skeleton along the cardiac cycle is provided, enriching the information obtained from cycle-average WSS. Among the main findings, it emerges that on the carotid bifurcation, instantaneous WSS fixed points co-localize with cycle-average WSS fixed points for a fraction of the cardiac cycle ranging from 0 to [Formula: see text]; a persistent instantaneous WSS fixed point confined on the aneurysm dome does not co-localize with the cycle-average low-WSS region. In conclusion, the here presented approach shows the potential to speed up studies on the physiological significance of WSS topological skeleton in cardiovascular flows, ultimately increasing the chance of finding mechanistic explanations to clinical observations.
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Affiliation(s)
- Valentina Mazzi
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129, Turin, Italy
- PolitoBIOMed Lab, Politecnico di Torino, Turin, Italy
| | - Diego Gallo
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129, Turin, Italy
- PolitoBIOMed Lab, Politecnico di Torino, Turin, Italy
| | - Karol Calò
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129, Turin, Italy
- PolitoBIOMed Lab, Politecnico di Torino, Turin, Italy
| | - Mehdi Najafi
- Biomedical Simulation Laboratory, Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada
| | | | - Giuseppe De Nisco
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129, Turin, Italy
- PolitoBIOMed Lab, Politecnico di Torino, Turin, Italy
| | - David A Steinman
- Biomedical Simulation Laboratory, Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada
| | - Umberto Morbiducci
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129, Turin, Italy.
- PolitoBIOMed Lab, Politecnico di Torino, Turin, Italy.
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Effect of Ambient Temperature Changes on Blood Flow in Anterior Cerebral Artery of Patients with Skull Prosthesis. World Neurosurg 2019; 135:e358-e365. [PMID: 31837495 DOI: 10.1016/j.wneu.2019.11.171] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 11/28/2019] [Accepted: 11/29/2019] [Indexed: 11/23/2022]
Abstract
BACKGROUND In many cases, an injury to the head leads to the replacement of a part of the skull with materials such as titanium and polyether ether ketone. METHODS Three-dimensional heads model of 15 healthy individuals and 13 patients were prepared. The models were simulated using thermal fluid structure interaction analysis to evaluate the effects of cold (5°C) and hot (55°C) temperatures of the skull on the conditions of blood flow in the anterior cerebral artery. RESULTS The results showed negligible changes (<3%) in wall shear stress (WSS) vessel and von Mises stress between the healthy individuals and patients both at 25°C and 55°C. However, at 5°C, the values of these 2 parameters in the patients were 2.1 and 2.5 times those in healthy individuals, respectively. The value of WSS in healthy individuals and the patients in cold temperature was 1.2 and 2.9 times those at normal temperature. The corresponding values for von Mises stress were 1.1 and 2.2, respectively. Accordingly, the stress changes between cold and hot ambient temperatures were found to be negligible in all samples. CONCLUSIONS The changes in stress were significant only for the patients when exposed to cold ambient temperature, and only in patients, exposure to a cold ambient temperature significantly increased the risks of vascular aneurysm and damage to the brain tissue surrounding the blood vessels. These risks were found to be negligible for both healthy individuals and patients when exposed to hot ambient temperature and also for healthy individuals exposed to cold ambient temperature.
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10
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Meuschke M, Oeltze-Jafra S, Beuing O, Preim B, Lawonn K. Classification of Blood Flow Patterns in Cerebral Aneurysms. IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS 2019; 25:2404-2418. [PMID: 29994310 DOI: 10.1109/tvcg.2018.2834923] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We present a Cerebral Aneurysm Vortex Classification (CAVOCLA) that allows to classify blood flow in cerebral aneurysms. Medical studies assume a strong relation between the progression and rupture of aneurysms and flow patterns. To understand how flow patterns impact the vessel morphology, they are manually classified according to predefined classes. However, manual classifications are time-consuming and exhibit a high inter-observer variability. In contrast, our approach is more objective and faster than manual methods. The classification of integral lines, representing steady or unsteady blood flow, is based on a mapping of the aneurysm surface to a hemisphere by calculating polar-based coordinates. The lines are clustered and for each cluster a representative is calculated. Then, the polar-based coordinates are transformed to the representative as basis for the classification. Classes are based on the flow complexity. The classification results are presented by a detail-on-demand approach using a visual transition from the representative over an enclosing surface to the associated lines. Based on seven representative datasets, we conduct an informal interview with five domain experts to evaluate the system. They confirmed that CAVOCLA allows for a robust classification of intra-aneurysmal flow patterns. The detail-on-demand visualization enables an efficient exploration and interpretation of flow patterns.
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11
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Goubergrits L, Hellmeier F, Bruening J, Spuler A, Hege HC, Voss S, Janiga G, Saalfeld S, Beuing O, Berg P. Multiple Aneurysms AnaTomy CHallenge 2018 (MATCH): uncertainty quantification of geometric rupture risk parameters. Biomed Eng Online 2019; 18:35. [PMID: 30909934 PMCID: PMC6434802 DOI: 10.1186/s12938-019-0657-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 03/19/2019] [Indexed: 03/04/2023] Open
Abstract
Background Geometric parameters have been proposed for prediction of cerebral aneurysm rupture risk. Predicting the rupture risk for incidentally detected unruptured aneurysms could help clinicians in their treatment decision. However, assessment of geometric parameters depends on several factors, including the spatial resolution of the imaging modality used and the chosen reconstruction procedure. The aim of this study was to investigate the uncertainty of a variety of previously proposed geometric parameters for rupture risk assessment, caused by variability of reconstruction procedures. Materials 26 research groups provided segmentations and surface reconstructions of five cerebral aneurysms as part of the Multiple Aneurysms AnaTomy CHallenge (MATCH) 2018. 40 dimensional and non-dimensional geometric parameters, describing aneurysm size, neck size, and irregularity of aneurysm shape, were computed. The medians as well as the absolute and relative uncertainties of the parameters were calculated. Additionally, linear regression analysis was performed on the absolute uncertainties and the median parameter values. Results A large variability of relative uncertainties in the range between 3.9 and 179.8% was found. Linear regression analysis indicates that some parameters capture similar geometric aspects. The lowest uncertainties < 6% were found for the non-dimensional parameters isoperimetric ratio, convexity ratio, and ellipticity index. Uncertainty of 2D and 3D size parameters was significantly higher than uncertainty of 1D parameters. The most extreme uncertainties > 80% were found for some curvature parameters. Conclusions Uncertainty analysis is essential on the road to clinical translation and use of rupture risk prediction models. Uncertainty quantification of geometric rupture risk parameters provided by this study may help support development of future rupture risk prediction models. Electronic supplementary material The online version of this article (10.1186/s12938-019-0657-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Leonid Goubergrits
- Institute for Computational and Imaging Science in Cardiovascular Medicine, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.
| | - Florian Hellmeier
- Institute for Computational and Imaging Science in Cardiovascular Medicine, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Jan Bruening
- Institute for Computational and Imaging Science in Cardiovascular Medicine, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | | | | | - Samuel Voss
- Department of Fluid Dynamics and Technical Flows, University of Magdeburg, Magdeburg, Germany.,Forschungscampus STIMULATE, Magdeburg, Germany
| | - Gábor Janiga
- Department of Fluid Dynamics and Technical Flows, University of Magdeburg, Magdeburg, Germany.,Forschungscampus STIMULATE, Magdeburg, Germany
| | - Sylvia Saalfeld
- Department of Simulation and Graphics, University of Magdeburg, Magdeburg, Germany.,Forschungscampus STIMULATE, Magdeburg, Germany
| | - Oliver Beuing
- Institute of Neuroradiology, University Hospital Magdeburg, Magdeburg, Germany.,Forschungscampus STIMULATE, Magdeburg, Germany
| | - Philipp Berg
- Department of Fluid Dynamics and Technical Flows, University of Magdeburg, Magdeburg, Germany.,Forschungscampus STIMULATE, Magdeburg, Germany
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Meuschke M, Gunther T, Berg P, Wickenhofer R, Preim B, Lawonn K. Visual Analysis of Aneurysm Data using Statistical Graphics. IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS 2018; 25:997-1007. [PMID: 30130202 DOI: 10.1109/tvcg.2018.2864509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This paper presents a framework to explore multi-field data of aneurysms occurring at intracranial and cardiac arteries by using statistical graphics. The rupture of an aneurysm is often a fatal scenario, whereas during treatment serious complications for the patient can occur. Whether an aneurysm ruptures or whether a treatment is successful depends on the interaction of different morphological such as wall deformation and thickness, and hemodynamic attributes like wall shear stress and pressure. Therefore, medical researchers are very interested in better understanding these relationships. However, the required analysis is a time-consuming process, where suspicious wall regions are difficult to detect due to the time-dependent behavior of the data. Our proposed visualization framework enables medical researchers to efficiently assess aneurysm risk and treatment options. This comprises a powerful set of views including 2D and 3D depictions of the aneurysm morphology as well as statistical plots of different scalar fields. Brushing and linking aids the user to identify interesting wall regions and to understand the influence of different attributes on the aneurysm's state. Moreover, a visual comparison of pre- and post-treatment as well as different treatment options is provided. Our analysis techniques are designed in collaboration with domain experts, e.g., physicians, and we provide details about the evaluation.
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ARANDA ALFREDO, VALENCIA ALVARO. STUDY ON THE RELATIONSHIP BETWEEN WALL SHEAR STRESS AND ASPECT RATIO OF CEREBRAL ANEURYSMS WITH DIFFERENT PRESSURE DIFFERENCES USING CFD SIMULATIONS. J MECH MED BIOL 2018. [DOI: 10.1142/s0219519418500550] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
CFD simulations were performed for 60 human cerebral aneurysms (30 previously ruptured and 30 previously unruptured) to study the behavior of the time-averaged wall shear stress (TAWSS) with respect to the aspect ratio (AR), implementing a set of low, normal, and high-pressure differences between the inlet and the outlets of each artery. It is well known that there exists a direct relationship between TAWSS and the rupture. In this investigation, we presented an important result because the condition of the pressure among the branches and the AR may be measured in any patient, then a slope may be associated, and finally a TAWSS may be estimated. We found that when the pressure difference increased, the absolute slopes between TAWSS and AR increased as well. Also, the magnitude of the slope in the previously unruptured aneurysms was 4.7 times the slope in the previously ruptured aneurysms. On the other hand, TAWSS was higher in the previously unruptured aneurysm than previously ruptured aneurysms due to the unruptured aneurysms that have a smaller surface area. Furthermore, we analyzed the relationship between TAWSS and other geometric parameters of the aneurysm, such as bottleneck and non-sphericity index; however, no correlation was found for either cases.
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Affiliation(s)
- ALFREDO ARANDA
- Department of Mechanical Engineering, Universidad de Chile, Beauchef 851, Santiago 8370456, Chile
| | - ALVARO VALENCIA
- Department of Mechanical Engineering, Universidad de Chile, Beauchef 851, Santiago 8370456, Chile
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Arzani A, Shadden SC. Wall shear stress fixed points in cardiovascular fluid mechanics. J Biomech 2018; 73:145-152. [DOI: 10.1016/j.jbiomech.2018.03.034] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 03/09/2018] [Accepted: 03/21/2018] [Indexed: 12/13/2022]
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Longo M, Granata F, Racchiusa S, Mormina E, Grasso G, Longo GM, Garufi G, Salpietro FM, Alafaci C. Role of Hemodynamic Forces in Unruptured Intracranial Aneurysms: An Overview of a Complex Scenario. World Neurosurg 2017; 105:632-642. [DOI: 10.1016/j.wneu.2017.06.035] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 06/04/2017] [Accepted: 06/05/2017] [Indexed: 12/16/2022]
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Association of wall shear stress with intracranial aneurysm rupture: systematic review and meta-analysis. Sci Rep 2017; 7:5331. [PMID: 28706287 PMCID: PMC5509692 DOI: 10.1038/s41598-017-05886-w] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 05/31/2017] [Indexed: 11/24/2022] Open
Abstract
To evaluate the relationship between wall shear stress (WSS) magnitude and cerebral aneurysm rupture and provide new insight into the disparate computational fluid dynamics (CFD) findings concerning the role of WSS in intracranial aneurysm (IA) rupture. A systematic electronic database (PubMed, Medline, Springer, and EBSCO) search was conducted for all accessible published articles up to July 1, 2016, with no restriction on the publication year. Abstracts, full-text manuscripts, and the reference lists of retrieved articles were analyzed. Random effects meta-analysis was used to pool the complication rates across studies. Twenty-two studies containing CFD data on 1257 patients with aneurysms were included in the analysis. A significantly higher rate of low WSS (0–1.5 Pa) was found in ruptured aneurysms (odds ratio [OR] 2.17; 95% confidence interval [CI], 1.73–2.62). The pooled analyses across 14 studies with low WSS showed significantly lower mean WSS (0.64 vs. 1.4 Pa) (p = 0.037) in the ruptured group. This meta-analysis provides evidence that decreased local WSS may be an important predictive parameter of IA rupture.
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Association between hemodynamics, morphology, and rupture risk of intracranial aneurysms: a computational fluid modeling study. Neurol Sci 2017; 38:1009-1018. [PMID: 28285454 PMCID: PMC5486504 DOI: 10.1007/s10072-017-2904-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 03/07/2017] [Indexed: 12/22/2022]
Abstract
The objective of the study was to examine the correlations between intracranial aneurysm morphology and wall shear stress (WSS) to identify reliable predictors of rupture risk. Seventy-two intracranial aneurysms (41 ruptured and 31 unruptured) from 63 patients were studied retrospectively. All aneurysms were divided into two categories: narrow (aspect ratio ≥1.4) and wide-necked (aspect ratio <1.4 or neck width ≥4 mm). Computational fluid dynamics was used to determine the distribution of WSS, which was analyzed between different morphological groups and between ruptured and unruptured aneurysms. Sections of the walls of clipped aneurysms were stained with hematoxylin–eosin, observed under a microscope, and photographed. Ruptured aneurysms were statistically more likely to have a greater low WSS area ratio (LSAR) (P = 0.001) and higher aneurysms parent WSS ratio (P = 0.026) than unruptured aneurysms. Narrow-necked aneurysms were statistically more likely to have a larger LSAR (P < 0.001) and lower values of MWSS (P < 0.001), mean aneurysm-parent WSS ratio (P < 0.001), HWSS (P = 0.012), and the highest aneurysm-parent WSS ratio (P < 0.001) than wide-necked aneurysms. The aneurysm wall showed two different pathological changes associated with high or low WSS in wide-necked aneurysms. Aneurysm morphology could affect the distribution and magnitude of WSS on the basis of differences in blood flow. Both high and low WSS could contribute to focal wall damage and rupture through different mechanisms associated with each morphological type.
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Meuschke M, Voss S, Beuing O, Preim B, Lawonn K. Combined Visualization of Vessel Deformation and Hemodynamics in Cerebral Aneurysms. IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS 2017; 23:761-770. [PMID: 27875190 DOI: 10.1109/tvcg.2016.2598795] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We present the first visualization tool that combines patient-specific hemodynamics with information about the vessel wall deformation and wall thickness in cerebral aneurysms. Such aneurysms bear the risk of rupture, whereas their treatment also carries considerable risks for the patient. For the patient-specific rupture risk evaluation and treatment analysis, both morphological and hemodynamic data have to be investigated. Medical researchers emphasize the importance of analyzing correlations between wall properties such as the wall deformation and thickness, and hemodynamic attributes like the Wall Shear Stress and near-wall flow. Our method uses a linked 2.5D and 3D depiction of the aneurysm together with blood flow information that enables the simultaneous exploration of wall characteristics and hemodynamic attributes during the cardiac cycle. We thus offer medical researchers an effective visual exploration tool for aneurysm treatment risk assessment. The 2.5D view serves as an overview that comprises a projection of the vessel surface to a 2D map, providing an occlusion-free surface visualization combined with a glyph-based depiction of the local wall thickness. The 3D view represents the focus upon which the data exploration takes place. To support the time-dependent parameter exploration and expert collaboration, a camera path is calculated automatically, where the user can place landmarks for further exploration of the properties. We developed a GPU-based implementation of our visualizations with a flexible interactive data exploration mechanism. We designed our techniques in collaboration with domain experts, and provide details about the evaluation.
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Sejkorová A, Dennis KD, Švihlová H, Petr O, Lanzino G, Hejčl A, Dragomir-Daescu D. Hemodynamic changes in a middle cerebral artery aneurysm at follow-up times before and after its rupture: a case report and a review of the literature. Neurosurg Rev 2016; 40:329-338. [DOI: 10.1007/s10143-016-0795-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 10/03/2016] [Accepted: 10/17/2016] [Indexed: 11/30/2022]
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Can A, Du R. Association of Hemodynamic Factors With Intracranial Aneurysm Formation and Rupture: Systematic Review and Meta-analysis. Neurosurgery 2016; 78:510-20. [PMID: 26516819 DOI: 10.1227/neu.0000000000001083] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Recent evidence suggests a link between the magnitude and distribution of hemodynamic factors and the formation and rupture of intracranial aneurysms. However, there are many conflicting results. OBJECTIVE To quantify the effect of hemodynamic factors on aneurysm formation and their association with ruptured aneurysms. METHODS We performed a systematic review and meta-analysis through October 2014. Analysis of the effects of hemodynamic factors on aneurysm formation was performed by pooling the results of studies that compared geometrical models of intracranial aneurysms and "preaneurysm" models where the aneurysm was artificially removed. Furthermore, we calculated pooled standardized mean differences between ruptured and unruptured aneurysms to quantify the association of hemodynamic factors with ruptured aneurysms. Standard PRISMA guidelines were followed. RESULTS The hemodynamic factors that showed high positive correlations with location of aneurysm formation were high wall shear stress (WSS) and high gradient oscillatory number, with pooled proportions of 78.8% and 85.7%, respectively. Positive correlations were largely seen in bifurcation aneurysms, whereas negative correlations were seen in sidewall aneurysms. Mean and normalized WSS were significantly lower and low shear area significantly higher in ruptured aneurysms. CONCLUSION Pooled analyses of computational fluid dynamics models suggest that an increase in WSS and gradient oscillatory number may contribute to aneurysm formation, whereas low WSS is associated with ruptured aneurysms. The location of the aneurysm at the bifurcation or sidewall may influence the correlation of these hemodynamic factors.
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Affiliation(s)
- Anil Can
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
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Huang ZQ, Meng ZH, Hou ZJ, Huang SQ, Chen JN, Yu H, Feng LJ, Wang QJ, Li PA, Wen ZB. Geometric Parameter Analysis of Ruptured and Unruptured Aneurysms in Patients with Symmetric Bilateral Intracranial Aneurysms: A Multicenter CT Angiography Study. AJNR Am J Neuroradiol 2016; 37:1413-7. [PMID: 27102312 PMCID: PMC7960285 DOI: 10.3174/ajnr.a4764] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 01/28/2016] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND PURPOSE Previous studies of geometric and morphologic parameters of intracranial aneurysms have been conducted to determine rupture risk, which remains incompletely defined due to patient-specific risk factors, such as sex, hypertension, and age. To this end, we compared characteristics of ruptured and unruptured aneurysms in the same patients with symmetric bilateral intracranial aneurysms. MATERIALS AND METHODS Between January 2008 and March 2014, 2361 patients with 2674 aneurysms were diagnosed by CT angiography or surgical findings at 4 medical centers. Geometric and morphologic parameters examined for symmetric bilateral intracranial aneurysms comprised aneurysm wall regularity, size, neck width, aspect ratio, size ratio, neck-to-parent artery ratio, and area ratio. Univariate and multivariate statistical analyses were performed to determine independent risk factors for rupture. RESULTS Sixty-three patients (48 women, 15 men; mean age, 62.5 ± 9.8 years) with symmetric bilateral aneurysms were eligible for the study and were included. The most frequent aneurysm location was the posterior communicating artery. Univariate analysis disclosed that aneurysm size, aspect ratio, size ratio, area ratio, and irregular wall differed between patients with ruptured and unruptured aneurysms. Multivariate analysis indicated that aspect ratio of ≥1.6 (adjusted OR, 9.521; 95% CI, 2.182-41.535), area ratio of ≥1.5 (adjusted OR, 4.089; 95% CI, 1.247-13.406), and irregular shape (adjusted OR, 10.443; 95% CI 3.394-32.135) were significant predictive factors for aneurysm rupture after adjustment for aneurysm size. CONCLUSIONS An aspect ratio of ≥1.6, area ratio of ≥1.5, and irregular wall are associated with aneurysm rupture independent of aneurysm size and patient characteristics. These characteristics alone can help in distinguishing ruptured bilateral intracranial aneurysms from unruptured ones.
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Affiliation(s)
- Z-Q Huang
- From the Medical Image Center (Z.-Q.H., H.Y., L.-J.F., Z.-B.W.) Medical Image Center (Z.-Q.H., Z.-H.M., J.-N.C.)
| | - Z-H Meng
- Medical Image Center (Z.-Q.H., Z.-H.M., J.-N.C.)
| | - Z-J Hou
- Department of Radiology (Z.-J.H.), The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong Province, China
| | - S-Q Huang
- Department of Radiology (S.-Q.H.), Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - J-N Chen
- Medical Image Center (Z.-Q.H., Z.-H.M., J.-N.C.)
| | - H Yu
- From the Medical Image Center (Z.-Q.H., H.Y., L.-J.F., Z.-B.W.)
| | - L-J Feng
- From the Medical Image Center (Z.-Q.H., H.Y., L.-J.F., Z.-B.W.)
| | - Q-J Wang
- Department of Neurosurgery (Q.-J.W.), Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - P-A Li
- Department of Neurosurgery (P.-A.L.), Yuebei People's Hospital, Shantou University Medical College, Shantou, Guangdong Province, China
| | - Z-B Wen
- From the Medical Image Center (Z.-Q.H., H.Y., L.-J.F., Z.-B.W.)
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Janiga G, Berg P, Sugiyama S, Kono K, Steinman DA. The Computational Fluid Dynamics Rupture Challenge 2013—Phase I: prediction of rupture status in intracranial aneurysms. AJNR Am J Neuroradiol 2015; 36:530-6. [PMID: 25500315 DOI: 10.3174/ajnr.a4157] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Rupture risk assessment for intracranial aneurysms remains challenging, and risk factors, including wall shear stress, are discussed controversially. The primary purpose of the presented challenge was to determine how consistently aneurysm rupture status and rupture site could be identified on the basis of computational fluid dynamics. MATERIALS AND METHODS Two geometrically similar MCA aneurysms were selected, 1 ruptured, 1 unruptured. Participating computational fluid dynamics groups were blinded as to which case was ruptured. Participants were provided with digitally segmented lumen geometries and, for this phase of the challenge, were free to choose their own flow rates, blood rheologies, and so forth. Participants were asked to report which case had ruptured and the likely site of rupture. In parallel, lumen geometries were provided to a group of neurosurgeons for their predictions of rupture status and site. RESULTS Of 26 participating computational fluid dynamics groups, 21 (81%) correctly identified the ruptured case. Although the known rupture site was associated with low and oscillatory wall shear stress, most groups identified other sites, some of which also experienced low and oscillatory shear. Of the 43 participating neurosurgeons, 39 (91%) identified the ruptured case. None correctly identified the rupture site. CONCLUSIONS Geometric or hemodynamic considerations favor identification of rupture status; however, retrospective identification of the rupture site remains a challenge for both engineers and clinicians. A more precise understanding of the hemodynamic factors involved in aneurysm wall pathology is likely required for computational fluid dynamics to add value to current clinical decision-making regarding rupture risk.
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Affiliation(s)
- G Janiga
- From the Department of Fluid Dynamics and Technical Flows (G.J., P.B.), University of Magdeburg, Magdeburg, Germany
| | - P Berg
- From the Department of Fluid Dynamics and Technical Flows (G.J., P.B.), University of Magdeburg, Magdeburg, Germany
| | - S Sugiyama
- Department of Neurosurgery (S.S.), Tohoku University Graduate School of Medicine, Miyagi, Japan
| | - K Kono
- Department of Neurosurgery (K.K.), Wakayama Rosai Hospital, Wakayama, Japan
| | - D A Steinman
- Department of Mechanical and Industrial Engineering (D.A.S.), University of Toronto, Toronto, Ontario, Canada
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Xiang J, Yu J, Snyder KV, Levy EI, Siddiqui AH, Meng H. Hemodynamic-morphological discriminant models for intracranial aneurysm rupture remain stable with increasing sample size. J Neurointerv Surg 2014; 8:104-10. [PMID: 25488922 DOI: 10.1136/neurintsurg-2014-011477] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 11/15/2014] [Indexed: 11/03/2022]
Abstract
BACKGROUND We previously established three logistic regression models for discriminating intracranial aneurysm rupture status based on morphological and hemodynamic analysis of 119 aneurysms. In this study, we tested if these models would remain stable with increasing sample size, and investigated sample sizes required for various confidence levels (CIs). METHODS We augmented our previous dataset of 119 aneurysms into a new dataset of 204 samples by collecting an additional 85 consecutive aneurysms, on which we performed flow simulation and calculated morphological and hemodynamic parameters, as done previously. We performed univariate significance tests on these parameters, and multivariate logistic regression on significant parameters. The new regression models were compared against the original models. Receiver operating characteristics analysis was applied to compare the performance of regression models. Furthermore, we performed regression analysis based on bootstrapping resampling statistical simulations to explore how many aneurysm cases were required to generate stable models. RESULTS Univariate tests of the 204 aneurysms generated an identical list of significant morphological and hemodynamic parameters as previously (from the analysis of 119 cases). Furthermore, multivariate regression analysis produced three parsimonious predictive models that were almost identical to the previous ones, with model coefficients that had narrower CIs than the original ones. Bootstrapping showed that 10%, 5%, 2%, and 1% convergence levels of CI required 120, 200, 500, and 900 aneurysms, respectively. CONCLUSIONS Our original hemodynamic-morphological rupture prediction models are stable and improve with increasing sample size. Results from resampling statistical simulations provide guidance for designing future large multi-population studies.
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Affiliation(s)
- Jianping Xiang
- Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Mechanical and Aerospace Engineering, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, New York, USA
| | - Jihnhee Yu
- Department of Biostatistics, University at Buffalo, State University of New York, Buffalo, New York, USA
| | - Kenneth V Snyder
- Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Radiology, University at Buffalo, State University of New York, Buffalo, New York, USA
| | - Elad I Levy
- Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Radiology, University at Buffalo, State University of New York, Buffalo, New York, USA
| | - Adnan H Siddiqui
- Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Radiology, University at Buffalo, State University of New York, Buffalo, New York, USA
| | - Hui Meng
- Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Mechanical and Aerospace Engineering, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, New York, USA
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25
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Chung B, Cebral JR. CFD for Evaluation and Treatment Planning of Aneurysms: Review of Proposed Clinical Uses and Their Challenges. Ann Biomed Eng 2014; 43:122-38. [DOI: 10.1007/s10439-014-1093-6] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 08/08/2014] [Indexed: 11/29/2022]
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26
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In vitro study of hemodynamic treatment improvement: Hunterian ligation of a fenestrated basilar artery aneurysm after coiling. Int J Artif Organs 2014; 37:325-35. [PMID: 24811187 DOI: 10.5301/ijao.5000314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/04/2014] [Indexed: 11/20/2022]
Abstract
Hunterian ligation affecting hemodynamics in vessels was proposed to avoid rebleeding in a case of a fenestrated basilar artery aneurysm after incomplete coil occlusion. We studied the hemodynamics in vitro to predict the hemodynamic changes near the aneurysm remnant caused by Hunterian ligation. A transparent model was fabricated based on three-dimensional rotational angiography imaging. Arteries were segmented and reconstructed. Pulsatile flow in the artery segments near the partially occluded (coiled) aneurysm was investigated by means of particle image velocimetry. The hemodynamic situation was investigated before and after Hunterian ligation of either the left or the right vertebral artery (LVA/RVA). Since post-ligation flow rate in the basilar artery was unknown, reduced and retained flow rates were simulated for both ligation options. Flow in the RVA and in the corresponding fenestra vessel is characterized by a vortex at the vertebrobasilar junction, whereas the LVA exhibits undisturbed laminar flow. Both options (RVA or LVA ligation) cause a significant flow reduction near the aneurysm remnant with a retained flow rate. The impact of RVA ligation is, however, significantly higher. This in vitro case study shows that flow reduction near the aneurysm remnant can be achieved by Hunterian ligation and that this effect depends largely on the selection of the ligated vessel. Thus the ability of the proposed in vitro pipe-line to improve hemodynamic impact of the proposed therapy was successfully proved.
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Pereira VM, Brina O, Bijlenga P, Bouillot P, Narata AP, Schaller K, Lovblad KO, Ouared R. Wall shear stress distribution of small aneurysms prone to rupture: a case-control study. Stroke 2013; 45:261-4. [PMID: 24253545 DOI: 10.1161/strokeaha.113.003247] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Subarachnoid hemorrhage after intracranial aneurysm rupture remains a serious condition. We performed a case-control study to evaluate the use of computed hemodynamics to detect cerebral aneurysms prone to rupture. METHODS Four patients with incidental aneurysms that ultimately ruptured (cases) were studied after initially being included in a prospective database including their 3-dimensional imaging before rupture. Ruptures were located in different arterial segments: M1 segment of the middle cerebral artery; basilar tip; posterior inferior cerebellar artery; and anterior communicating artery. For each case, 5 controls matched by location and size were randomly selected. An empirical cumulative distribution function of aneurysm wall shear stress percentiles was evaluated for every case and used to define a critical prone-to-rupture range. Univariate logistic regression analysis was then used to assess the individual risk of rupture. RESULTS A cumulative wall shear stress distribution characterizing a hemodynamic prone-to-rupture range for small-sized aneurysms was identified and fitted independent of the location. Sensitivity and specificity of the preliminary tests were 90% and 93%, respectively. CONCLUSIONS The wall shear stress cumulative probability function may be a potential predictor of small-sized aneurysm rupture.
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Affiliation(s)
- Vitor Mendes Pereira
- From the Interventional Neuroradiology Unit, Service of Neuroradiology (V.M.P., O.B., P.B., A.P.N., K.-O.L., R.O.) and Service of Neurosurgery (P.B., K.S.), Faculty of Medicine, University of Geneva Hospitals, Geneva, Switzerland
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Propose a wall shear stress divergence to estimate the risks of intracranial aneurysm rupture. ScientificWorldJournal 2013; 2013:508131. [PMID: 24191140 PMCID: PMC3804446 DOI: 10.1155/2013/508131] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 08/29/2013] [Indexed: 11/17/2022] Open
Abstract
Although wall shear stress (WSS) has long been considered a critical indicator of intracranial aneurysm rupture, there is still no definite conclusion as to whether a high or a low WSS results in aneurysm rupture. The reason may be that the effect of WSS direction has not been fully considered. The objectives of this study are to investigate the magnitude of WSS (|WSS|) and its divergence on the aneurysm surface and to test the significance of both in relation to the aneurysm rupture. Patient-specific computational fluid dynamics (CFD) was used to compute WSS and wall shear stress divergence (WSSD) on the aneurysm surface for nineteen patients. Our results revealed that if high |WSS| is stretching aneurysm luminal surface, and the stretching region is concentrated, the aneurysm is under a high risk of rupture. It seems that, by considering both direction and magnitude of WSS, WSSD may be a better indicator for the risk estimation of aneurysm rupture (154).
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Pereira VM, Brina O, Gonzalez AM, Narata AP, Ouared R, Karl-Olof L. Biology and hemodynamics of aneurismal vasculopathies. Eur J Radiol 2013; 82:1606-17. [DOI: 10.1016/j.ejrad.2012.12.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 12/11/2012] [Accepted: 12/13/2012] [Indexed: 10/27/2022]
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Inthavong K, Shang Y, Tu J. Surface mapping for visualization of wall stresses during inhalation in a human nasal cavity. Respir Physiol Neurobiol 2013; 190:54-61. [PMID: 24051139 DOI: 10.1016/j.resp.2013.09.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 09/09/2013] [Accepted: 09/10/2013] [Indexed: 11/25/2022]
Abstract
Airflow analysis can assist in better understanding the physiology however the human nasal cavity is an extremely complicated geometry that is difficult to visualize in 3D space, let alone in 2D space. In this paper, an anatomically accurate 3D surface of the nasal passages derived from CT data was unwrapped and transformed into a 2D space, into a UV-domain (where u and v are the coordinates) to allow a complete view of the entire wrapped surface. This visualization technique allows surface flow parameters to be analyzed with greater precision. A UV-unwrapping tool is developed and a strategy is presented to allow deeper analysis to be performed. This includes (i) the ability to present instant comparisons of geometry and flow variables between any number of different nasal cavity models through normalization of the 2D unwrapped surface; (ii) visualization of an entire surface in one view and; (iii) a planar surface that allows direct 1D and 2D analytical solutions of diffusion of inhaled vapors and particles through the nasal walls. This work lays a foundation for future investigations that correlates adverse and therapeutic health responses to local inhalation of gases and particles.
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Affiliation(s)
- Kiao Inthavong
- School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Australia
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Xiang J, Tutino VM, Snyder KV, Meng H. CFD: computational fluid dynamics or confounding factor dissemination? The role of hemodynamics in intracranial aneurysm rupture risk assessment. AJNR Am J Neuroradiol 2013; 35:1849-57. [PMID: 24029393 DOI: 10.3174/ajnr.a3710] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Image-based computational fluid dynamics holds a prominent position in the evaluation of intracranial aneurysms, especially as a promising tool to stratify rupture risk. Current computational fluid dynamics findings correlating both high and low wall shear stress with intracranial aneurysm growth and rupture puzzle researchers and clinicians alike. These conflicting findings may stem from inconsistent parameter definitions, small datasets, and intrinsic complexities in intracranial aneurysm growth and rupture. In Part 1 of this 2-part review, we proposed a unifying hypothesis: both high and low wall shear stress drive intracranial aneurysm growth and rupture through mural cell-mediated and inflammatory cell-mediated destructive remodeling pathways, respectively. In the present report, Part 2, we delineate different wall shear stress parameter definitions and survey recent computational fluid dynamics studies, in light of this mechanistic heterogeneity. In the future, we expect that larger datasets, better analyses, and increased understanding of hemodynamic-biologic mechanisms will lead to more accurate predictive models for intracranial aneurysm risk assessment from computational fluid dynamics.
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Affiliation(s)
- J Xiang
- From the Toshiba Stroke and Vascular Research Center (J.X., V.M.T., K.V.S., H.M.) Departments of Neurosurgery (J.X.)
| | - V M Tutino
- From the Toshiba Stroke and Vascular Research Center (J.X., V.M.T., K.V.S., H.M.) Biomedical Engineering (V.M.T.)
| | - K V Snyder
- From the Toshiba Stroke and Vascular Research Center (J.X., V.M.T., K.V.S., H.M.)
| | - H Meng
- From the Toshiba Stroke and Vascular Research Center (J.X., V.M.T., K.V.S., H.M.) Mechanical and Aerospace Engineering (H.M.), University at Buffalo, State University of New York, Buffalo, New York.
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Yu Y, Xu J, Fang Y, Wu X, Yang P, Jiang C, Qian Y, Liu J, Huang Q. Analysis of morphologic and hemodynamic parameters for unruptured posterior communicating artery aneurysms with oculomotor nerve palsy. AJNR Am J Neuroradiol 2013; 34:2187-91. [PMID: 23744688 DOI: 10.3174/ajnr.a3575] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Posterior communicating artery aneurysms with oculomotor nerve palsy may imply sudden enlargement of the aneurysm sac and have a high risk of rupture. Our aim was to identify the morphologic and hemodynamic parameters in this special period of aneurysm progression and to assess related rupture risk indices. MATERIALS AND METHODS We analyzed the morphologic and hemodynamic parameters of 9 unruptured posterior communicating artery aneurysms with oculomotor nerve palsy and 9 ruptured ones. The morphologic parameters were measured and calculated from patient-specific 3D rotational angiographic images, and pulsatile computational fluid dynamic simulation was then performed for hemodynamic parameters. RESULTS There was no significant statistical difference between the 2 groups in size, aspect ratio, size ratio, aneurysm angle, or vessel angle; analysis only demonstrated a significantly lower wall shear stress of the aneurysm wall in the symptomatic unruptured group in hemodynamics (P = .024), whereas there were no differences in wall shear stress of the parent artery, low wall shear stress area, and oscillatory shear index. CONCLUSIONS From morphologic and hemodynamic perspectives, we demonstrated that posterior communicating artery aneurysms with oculomotor nerve palsy had characteristics similar to those of ruptured ones, except for lower wall shear stress on the aneurysm wall, which might indicate an important role in aneurysm rupture.
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Affiliation(s)
- Y Yu
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
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Sadasivan C, Fiorella DJ, Woo HH, Lieber BB. Physical factors effecting cerebral aneurysm pathophysiology. Ann Biomed Eng 2013; 41:1347-65. [PMID: 23549899 DOI: 10.1007/s10439-013-0800-z] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2012] [Accepted: 03/21/2013] [Indexed: 12/21/2022]
Abstract
Many factors that are either blood-, wall-, or hemodynamics-borne have been associated with the initiation, growth, and rupture of intracranial aneurysms. The distribution of cerebral aneurysms around the bifurcations of the circle of Willis has provided the impetus for numerous studies trying to link hemodynamic factors (flow impingement, pressure, and/or wall shear stress) to aneurysm pathophysiology. The focus of this review is to provide a broad overview of such hemodynamic associations as well as the subsumed aspects of vascular anatomy and wall structure. Hemodynamic factors seem to be correlated to the distribution of aneurysms on the intracranial arterial tree and complex, slow flow patterns seem to be associated with aneurysm growth and rupture. However, both the prevalence of aneurysms in the general population and the incidence of ruptures in the aneurysm population are extremely low. This suggests that hemodynamic factors and purely mechanical explanations by themselves may serve as necessary, but never as necessary and sufficient conditions of this disease's causation. The ultimate cause is not yet known, but it is likely an additive or multiplicative effect of a handful of biochemical and biomechanical factors.
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Affiliation(s)
- Chander Sadasivan
- Department of Neurological Surgery, Stony Brook University Medical Center, 100 Nicolls Road, HSC T12, Room 080, Stony Brook, NY 11794-8122, USA
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Xu J, Yu Y, Wu X, Wu Y, Jiang C, Wang S, Huang Q, Liu J. Morphological and hemodynamic analysis of mirror posterior communicating artery aneurysms. PLoS One 2013; 8:e55413. [PMID: 23383184 PMCID: PMC3561240 DOI: 10.1371/journal.pone.0055413] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 12/21/2012] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND AND PURPOSE Hemodynamic factors are commonly believed to play an important role in the pathogenesis, progression, and rupture of cerebral aneurysms. In this study, we aimed to identify significant hemodynamic and morphological parameters that discriminate intracranial aneurysm rupture status using 3-dimensional-angiography and computational fluid dynamics technology. MATERIALS AND METHODS 3D-DSA was performed in 8 patients with mirror posterior communicating artery aneurysms (Pcom-MANs). Each pair was divided into ruptured and unruptured groups. Five morphological and three hemodynamic parameters were evaluated for significance with respect to rupture. RESULTS The normalized mean wall shear stress (WSS) of the aneurysm sac in the ruptured group was significantly lower than that in the unruptured group (0.52±0.20 versus 0.81±0.21, P = .012). The percentage of the low WSS area in the ruptured group was higher than that in the unruptured group (4.11±4.66% versus 0.02±0.06%, P = .018). The AR was 1.04±0.21 in the ruptured group, which was significantly higher than 0.70±0.17 in the unruptured group (P = .012). By contrast, parameters that had no significant differences between the two groups were OSI (P = .674), aneurysm size (P = .327), size ratio (P = .779), vessel angle (P = 1.000) and aneurysm inclination angle (P = 1.000). CONCLUSIONS Pcom-MANs may be a useful disease model to investigate possible causes of aneurysm rupture. The ruptured aneurysms manifested lower WSS, higher percentage of low WSS area, and higher AR, compared with the unruptured one. And hemodynamics is as important as morphology in discriminating aneurysm rupture status.
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Affiliation(s)
- Jinyu Xu
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Ying Yu
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Xi Wu
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Yongfa Wu
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Che Jiang
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Shengzhang Wang
- Department of Mechanics and Engineering Science, Fudan University, Shanghai, China
| | - Qinghai Huang
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
- * E-mail: (JL); (QH)
| | - Jianmin Liu
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
- * E-mail: (JL); (QH)
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