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Jeanbaptiste Zerlauth - One of the best experts on this subject based on the ideXlab platform.
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impact of metal artifact reduction software on image quality of gemstone spectral imaging dual energy cerebral ct angiography after Intracranial Aneurysm clipping
Neuroradiology, 2017Co-Authors: Vincent Dunet, Martine Bernasconi, Steven D. Hajdu, Reto Meuli, Roy Thomas Daniel, Jeanbaptiste ZerlauthAbstract:Purpose We aimed to assess the impact of metal artifact reduction software (MARs) on image quality of gemstone spectral imaging (GSI) dual-energy (DE) cerebral CT angiography (CTA) after Intracranial Aneurysm clipping.
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impact of metal artifact reduction software on image quality of gemstone spectral imaging dual energy cerebral ct angiography after Intracranial Aneurysm clipping
Neuroradiology, 2017Co-Authors: Vincent Dunet, Martine Bernasconi, Steven D. Hajdu, Reto Meuli, Roy Thomas Daniel, Jeanbaptiste ZerlauthAbstract:We aimed to assess the impact of metal artifact reduction software (MARs) on image quality of gemstone spectral imaging (GSI) dual-energy (DE) cerebral CT angiography (CTA) after Intracranial Aneurysm clipping. This retrospective study was approved by the institutional review board, which waived patient written consent. From January 2013 to September 2016, single source DE cerebral CTA were performed in 45 patients (mean age: 60 ± 9 years, male 9) after Intracranial Aneurysm clipping and reconstructed with and without MARs. Signal-to-noise (SNR), contrast-to-noise (CNR), and relative CNR (rCNR) ratios were calculated from attenuation values measured in the internal carotid artery (ICA) and middle cerebral artery (MCA). Volume of clip and artifacts and relative clip blurring reduction (rCBR) ratios were also measured at each energy level with/without MARs. Variables were compared between GSI and GSI-MARs using the paired Wilcoxon signed-rank test. MARs significantly reduced metal artifacts at all energy levels but 130 and 140 keV, regardless of clips’ location and number. The optimal rCBR was obtained at 110 and 80 keV, respectively, on GSI and GSI-MARs images, with up to 96% rCNR increase on GSI-MARs images. The best compromise between metal artifact reduction and rCNR was obtained at 70–75 and 65–70 keV for GSI and GSI-MARs images, respectively, with up to 15% rCBR and rCNR increase on GSI-MARs images. MARs significantly reduces metal artifacts on DE cerebral CTA after Intracranial Aneurysm clipping regardless of clips’ location and number. It may be used to reduce radiation dose while increasing CNR.
Hui Meng - One of the best experts on this subject based on the ideXlab platform.
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improving accuracy for finite element modeling of endovascular coiling of Intracranial Aneurysm
PLOS ONE, 2019Co-Authors: Robert J Damiano, Adnan H. Siddiqui, Vincent M Tutino, Saeb R Lamooki, Nikhil Paliwal, G F Dargush, Jason M Davies, Hui MengAbstract:Background Computer modeling of endovascular coiling intervention for Intracranial Aneurysm could enable a priori patient-specific treatment evaluation. To that end, we previously developed a finite element method (FEM) coiling technique, which incorporated simplified assumptions. To improve accuracy in capturing real-life coiling, we aimed to enhance the modeling strategies and experimentally test whether improvements lead to more accurate coiling simulations. Methods We previously modeled coils using a pre-shape based on mathematical curves and mechanical properties based on those of platinum wires. In the improved version, to better represent the physical properties of coils, we model coil pre-shapes based on how they are manufactured, and their mechanical properties based on their spring-like geometric structures. To enhance the deployment mechanics, we include coil advancement to the Aneurysm in FEM simulations. To test if these new strategies produce more accurate coil deployments, we fabricated silicone phantoms of 2 patient-specific Aneurysms in duplicate, deployed coils in each, and quantified coil distributions from intra-Aneurysmal cross-sections using coil density (CD) and lacunarity (L). These deployments were simulated 9 times each using the original and improved techniques, and CD and L were calculated for cross-sections matching those in the experiments. To compare the 2 simulation techniques, Euclidean distances (dMin, dMax, and dAvg) between experimental and simulation points in standardized CD-L space were evaluated. Univariate tests were performed to determine if these distances were significantly different between the 2 simulations. Results Coil deployments using the improved technique agreed better with experiments than the original technique. All dMin, dMax, and dAvg values were smaller for the improved technique, and the average values across all simulations for the improved technique were significantly smaller than those from the original technique (dMin: p = 0.014, dMax: p = 0.013, dAvg: p = 0.045). Conclusion Incorporating coil-specific physical properties and mechanics improves accuracy of FEM simulations of endovascular Intracranial Aneurysm coiling.
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cfd computational fluid dynamics or confounding factor dissemination the role of hemodynamics in Intracranial Aneurysm rupture risk assessment
American Journal of Neuroradiology, 2014Co-Authors: Jianping Xiang, Hui Meng, V M Tutino, Kenneth V SnyderAbstract:SUMMARY: 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 hemodynamicbiologic mechanisms will lead to more accurate predictive models for Intracranial Aneurysm risk assessment from computational fluid dynamics.
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high wss or low wss complex interactions of hemodynamics with Intracranial Aneurysm initiation growth and rupture toward a unifying hypothesis
American Journal of Neuroradiology, 2014Co-Authors: Hui Meng, Jianping Xiang, Vincent M Tutino, Adnan H. SiddiquiAbstract:Summary: Increasing detection of unruptured Intracranial Aneurysms, catastrophic outcomes from subarachnoid hemorrhage, and risks and cost of treatment necessitate defining objective predictive parameters of Aneurysm rupture risk. Image-based computational fluid dynamics models have suggested associations between hemodynamics and Intracranial Aneurysm rupture, albeit with conflicting findings regarding wall shear stress. We propose that the “high-versus-low wall shear stress” controversy is a manifestation of the complexity of Aneurysm pathophysiology, and both high and low wall shear stress can drive Intracranial Aneurysm growth and rupture. Low wall shear stress and high oscillatory shear index trigger an inflammatory-cell-mediated pathway, which could be associated with the growth and rupture of large, atherosclerotic Aneurysm phenotypes, while high wall shear stress combined with a positive wall shear stress gradient trigger a mural-cell-mediated pathway, which could be associated with the growth and rupture of small or secondary bleb Aneurysm phenotypes. This hypothesis correlates disparate Intracranial Aneurysm pathophysiology with the results of computational fluid dynamics in search of more reliable risk predictors.
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hemodynamic morphologic discriminants for Intracranial Aneurysm rupture
Stroke, 2011Co-Authors: Jianping Xiang, Sabareesh K. Natarajan, Markus Tremmel, J Mocco, Adnan H. Siddiqui, Elad I. Levy, Nelson L Hopkins, Hui MengAbstract:Background and purpose the purpose of this study was to identify significant morphological and hemodynamic parameters that discriminate Intracranial Aneurysm rupture status using 3-dimensional angiography and computational fluid dynamics. Methods one hundred nineteen Intracranial Aneurysms (38 ruptured, 81 unruptured) were analyzed from 3-dimensional angiographic images and computational fluid dynamics. Six morphological and 7 hemodynamic parameters were evaluated for significance with respect to rupture. Receiver operating characteristic analysis identified area under the curve (AUC) and optimal thresholds separating ruptured from unruptured Aneurysms for each parameter. Significant parameters were examined by multivariate logistic regression analysis in 3 predictive models-morphology only, hemodynamics only, and combined-to identify independent discriminants, and the AUC receiver operating characteristic of the predicted probability of rupture status was compared among these models. Results morphological parameters (size ratio, undulation index, ellipticity index, and nonsphericity index) and hemodynamic parameters (average wall shear stress [WSS], maximum intra-Aneurysmal WSS, low WSS area, average oscillatory shear index, number of vortices, and relative resident time) achieved statistical significance (P Conclusions all 3 models-morphological (based on size ratio), hemodynamic (based on WSS and oscillatory shear index), and combined-discriminate Intracranial Aneurysm rupture status with high AUC values. Hemodynamics is as important as morphology in discriminating Aneurysm rupture status.
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size ratio correlates with Intracranial Aneurysm rupture status a prospective study
Stroke, 2010Co-Authors: Maryam Rahman, Adnan H. Siddiqui, Elad I. Levy, Hui Meng, Janel Smietana, Erik F Hauck, Brian L Hoh, Nick Hopkins, J MoccoAbstract:Background and Purpose— The prediction of Intracranial Aneurysm (IA) rupture risk has generated significant controversy. The findings of the International Study of Unruptured Intracranial Aneurysms (ISUIA) that small anterior circulation Aneurysms (<7 mm) have a 0% risk of subarachnoid hemorrhage in 5 years is difficult to reconcile with other studies that reported a significant portion of ruptured IAs are small. These discrepancies have led to the search for better Aneurysm parameters to predict rupture. We previously reported that size ratio (SR), IA size divided by parent vessel diameter, correlated strongly with IA rupture status (ruptured versus unruptured). These data were all collected retrospectively off 3-dimensional angiographic images. Therefore, we performed a blinded prospective collection and evaluation of SR data from 2-dimensional angiographic images for a consecutive series of patients with ruptured and unruptured IAs. Methods— We prospectively enrolled 40 consecutive patients presenting ...
Vincent Dunet - One of the best experts on this subject based on the ideXlab platform.
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impact of metal artifact reduction software on image quality of gemstone spectral imaging dual energy cerebral ct angiography after Intracranial Aneurysm clipping
Neuroradiology, 2017Co-Authors: Vincent Dunet, Martine Bernasconi, Steven D. Hajdu, Reto Meuli, Roy Thomas Daniel, Jeanbaptiste ZerlauthAbstract:Purpose We aimed to assess the impact of metal artifact reduction software (MARs) on image quality of gemstone spectral imaging (GSI) dual-energy (DE) cerebral CT angiography (CTA) after Intracranial Aneurysm clipping.
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impact of metal artifact reduction software on image quality of gemstone spectral imaging dual energy cerebral ct angiography after Intracranial Aneurysm clipping
Neuroradiology, 2017Co-Authors: Vincent Dunet, Martine Bernasconi, Steven D. Hajdu, Reto Meuli, Roy Thomas Daniel, Jeanbaptiste ZerlauthAbstract:We aimed to assess the impact of metal artifact reduction software (MARs) on image quality of gemstone spectral imaging (GSI) dual-energy (DE) cerebral CT angiography (CTA) after Intracranial Aneurysm clipping. This retrospective study was approved by the institutional review board, which waived patient written consent. From January 2013 to September 2016, single source DE cerebral CTA were performed in 45 patients (mean age: 60 ± 9 years, male 9) after Intracranial Aneurysm clipping and reconstructed with and without MARs. Signal-to-noise (SNR), contrast-to-noise (CNR), and relative CNR (rCNR) ratios were calculated from attenuation values measured in the internal carotid artery (ICA) and middle cerebral artery (MCA). Volume of clip and artifacts and relative clip blurring reduction (rCBR) ratios were also measured at each energy level with/without MARs. Variables were compared between GSI and GSI-MARs using the paired Wilcoxon signed-rank test. MARs significantly reduced metal artifacts at all energy levels but 130 and 140 keV, regardless of clips’ location and number. The optimal rCBR was obtained at 110 and 80 keV, respectively, on GSI and GSI-MARs images, with up to 96% rCNR increase on GSI-MARs images. The best compromise between metal artifact reduction and rCNR was obtained at 70–75 and 65–70 keV for GSI and GSI-MARs images, respectively, with up to 15% rCBR and rCNR increase on GSI-MARs images. MARs significantly reduces metal artifacts on DE cerebral CTA after Intracranial Aneurysm clipping regardless of clips’ location and number. It may be used to reduce radiation dose while increasing CNR.
Jianping Xiang - One of the best experts on this subject based on the ideXlab platform.
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numerical simulation of patient specific endovascular stenting and coiling for Intracranial Aneurysm surgical planning
Journal of Translational Medicine, 2018Co-Authors: Xiaochang Leng, Yang Wang, Yeqing Jiang, Xiaolong Zhang, Jianping XiangAbstract:In this study, we develop reliable and practical virtual coiling and stenting methods for Intracranial Aneurysm surgical planning. Since the purpose of deploying coils and stents is to provide device geometries for subsequent accurate post-treatment computational fluid dynamics analysis, we do not need to accurately capture all the details such as the stress and force distribution for the devices and vessel walls. Our philosophy for developing these methods is to balance accuracy and practicality. We consider the mechanical properties of the devices and recapitulate the clinical practice using a finite element method (FEM) approach. At the same time, we apply some simplifications for FEM modeling to make our methods efficient. For the virtual coiling, the coils are modeled as 3D Euler–Bernoulli beam elements, which is computationally efficient and provides good geometry representation. During the stent deployment process, the stent–catheter system is transformed according to the centerline of the parent vessel since the final configuration of the stent is not dependent of the deployment history. The Aneurysm and vessel walls are assumed to be rigid and are fully constrained during the simulation. All stent–catheter system and coil–catheter system are prepared and packaged as a library which contains all types of stents, coils and catheters, which improves the efficiency of surgical planning process. The stent was delivered to the suitable position during the clinical treatment, achieving good expansion and apposition of the stent to the arterial wall. The coil was deployed into the Aneurysm sac and deformed to different shapes because of the stored strain energy during coil package process and the direction of the microcatheter. The method which we develop here could become surgical planning for Intracranial Aneurysm treatment in the clinical workflow.
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Numerical simulation of patient-specific endovascular stenting and coiling for Intracranial Aneurysm surgical planning
BMC, 2018Co-Authors: Xiaochang Leng, Yang Wang, Yeqing Jiang, Xiaolong Zhang, Jianping XiangAbstract:Abstract Background In this study, we develop reliable and practical virtual coiling and stenting methods for Intracranial Aneurysm surgical planning. Since the purpose of deploying coils and stents is to provide device geometries for subsequent accurate post-treatment computational fluid dynamics analysis, we do not need to accurately capture all the details such as the stress and force distribution for the devices and vessel walls. Our philosophy for developing these methods is to balance accuracy and practicality. Methods We consider the mechanical properties of the devices and recapitulate the clinical practice using a finite element method (FEM) approach. At the same time, we apply some simplifications for FEM modeling to make our methods efficient. For the virtual coiling, the coils are modeled as 3D Euler–Bernoulli beam elements, which is computationally efficient and provides good geometry representation. During the stent deployment process, the stent–catheter system is transformed according to the centerline of the parent vessel since the final configuration of the stent is not dependent of the deployment history. The Aneurysm and vessel walls are assumed to be rigid and are fully constrained during the simulation. All stent–catheter system and coil–catheter system are prepared and packaged as a library which contains all types of stents, coils and catheters, which improves the efficiency of surgical planning process. Results The stent was delivered to the suitable position during the clinical treatment, achieving good expansion and apposition of the stent to the arterial wall. The coil was deployed into the Aneurysm sac and deformed to different shapes because of the stored strain energy during coil package process and the direction of the microcatheter. Conclusions The method which we develop here could become surgical planning for Intracranial Aneurysm treatment in the clinical workflow
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cfd computational fluid dynamics or confounding factor dissemination the role of hemodynamics in Intracranial Aneurysm rupture risk assessment
American Journal of Neuroradiology, 2014Co-Authors: Jianping Xiang, Hui Meng, V M Tutino, Kenneth V SnyderAbstract:SUMMARY: 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 hemodynamicbiologic mechanisms will lead to more accurate predictive models for Intracranial Aneurysm risk assessment from computational fluid dynamics.
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high wss or low wss complex interactions of hemodynamics with Intracranial Aneurysm initiation growth and rupture toward a unifying hypothesis
American Journal of Neuroradiology, 2014Co-Authors: Hui Meng, Jianping Xiang, Vincent M Tutino, Adnan H. SiddiquiAbstract:Summary: Increasing detection of unruptured Intracranial Aneurysms, catastrophic outcomes from subarachnoid hemorrhage, and risks and cost of treatment necessitate defining objective predictive parameters of Aneurysm rupture risk. Image-based computational fluid dynamics models have suggested associations between hemodynamics and Intracranial Aneurysm rupture, albeit with conflicting findings regarding wall shear stress. We propose that the “high-versus-low wall shear stress” controversy is a manifestation of the complexity of Aneurysm pathophysiology, and both high and low wall shear stress can drive Intracranial Aneurysm growth and rupture. Low wall shear stress and high oscillatory shear index trigger an inflammatory-cell-mediated pathway, which could be associated with the growth and rupture of large, atherosclerotic Aneurysm phenotypes, while high wall shear stress combined with a positive wall shear stress gradient trigger a mural-cell-mediated pathway, which could be associated with the growth and rupture of small or secondary bleb Aneurysm phenotypes. This hypothesis correlates disparate Intracranial Aneurysm pathophysiology with the results of computational fluid dynamics in search of more reliable risk predictors.
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hemodynamic morphologic discriminants for Intracranial Aneurysm rupture
Stroke, 2011Co-Authors: Jianping Xiang, Sabareesh K. Natarajan, Markus Tremmel, J Mocco, Adnan H. Siddiqui, Elad I. Levy, Nelson L Hopkins, Hui MengAbstract:Background and purpose the purpose of this study was to identify significant morphological and hemodynamic parameters that discriminate Intracranial Aneurysm rupture status using 3-dimensional angiography and computational fluid dynamics. Methods one hundred nineteen Intracranial Aneurysms (38 ruptured, 81 unruptured) were analyzed from 3-dimensional angiographic images and computational fluid dynamics. Six morphological and 7 hemodynamic parameters were evaluated for significance with respect to rupture. Receiver operating characteristic analysis identified area under the curve (AUC) and optimal thresholds separating ruptured from unruptured Aneurysms for each parameter. Significant parameters were examined by multivariate logistic regression analysis in 3 predictive models-morphology only, hemodynamics only, and combined-to identify independent discriminants, and the AUC receiver operating characteristic of the predicted probability of rupture status was compared among these models. Results morphological parameters (size ratio, undulation index, ellipticity index, and nonsphericity index) and hemodynamic parameters (average wall shear stress [WSS], maximum intra-Aneurysmal WSS, low WSS area, average oscillatory shear index, number of vortices, and relative resident time) achieved statistical significance (P Conclusions all 3 models-morphological (based on size ratio), hemodynamic (based on WSS and oscillatory shear index), and combined-discriminate Intracranial Aneurysm rupture status with high AUC values. Hemodynamics is as important as morphology in discriminating Aneurysm rupture status.
Enju Lee - One of the best experts on this subject based on the ideXlab platform.
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endovascular coiling versus neurosurgical clipping in patients with unruptured Intracranial Aneurysm a systematic review
BMC Neurology, 2012Co-Authors: Jin Seub Hwang, Min Kyung Hyun, Hyun Joo Lee, Ji Eun Choi, Jonghee Kim, Na Rae Lee, Jinwon Kwon, Enju LeeAbstract:Background To compare the effects of endovascular coiling and neurosurgical clipping in patients with unruptured Intracranial Aneurysm.
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endovascular coiling versus neurosurgical clipping in patients with unruptured Intracranial Aneurysm a systematic review
BMC Neurology, 2012Co-Authors: Jin Seub Hwang, Min Kyung Hyun, Hyun Joo Lee, Ji Eun Choi, Jonghee Kim, Na Rae Lee, Jinwon Kwon, Enju LeeAbstract:To compare the effects of endovascular coiling and neurosurgical clipping in patients with unruptured Intracranial Aneurysm. Sixteen electronic databases were searched for articles published between 1950 and July 2010 to compare clinical outcomes of clipping and coiling. Researchers reviewed all searched articles and extracted data independently. The quality of studies and evidence were evaluated using MINORS and GRADEprofiler, respectively. The odds ratio (OR) was calculated using the inverse variance meta-analysis method for each study outcome. To assess heterogeneity of ORs across cohorts, Cochran’s Q statistic and I2 were used. Of 4160 studies, 24 were identified (n = 31865). Clipping resulted in significantly higher disability using the Glasgow Outcome Scale (OR, 2.38; 95% CI, 1.33–4.26) and Modified Rankin Scale (OR, 2.83; 95% CI, 1.42–5.63) when compared with coiling. ORs for complications were also higher with clipping (ORs for neurological and cardiac complications were 1.94 with a 95% confidence interval [CI] of 1.09–3.47 and 2.51 with a 95% CI of 1.15–5.50). Clipping resulted in significantly greater disability in the short term (≤6 m)(OR on the Glasgow Outcome Scale, 2.72; 95% CI, 1.16–6.34), but not in the long term (>6 m)(OR for Glasgow Outcome Scale, 2.12; 95% CI, 0.93–4.84). Coiling was a better procedure for treatment of unruptured Intracranial Aneurysm in terms of disability, complications, especially in the short term. Because of the limitations of the reviewed studies, further studies are required to support the present results.
