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Sadid SR, Kabir MS, Mahmud ST, Islam MS, Islam AHMW, Arafat MT. Segmenting 3D geometry of left coronary artery from coronary CT angiography using deep learning for hemodynamic evaluation. Biomed Phys Eng Express 2022; 8. [DOI: 10.1088/2057-1976/ac9e03] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 10/27/2022] [Indexed: 11/11/2022]
Abstract
Abstract
While coronary CT angiography (CCTA) is crucial for detecting several coronary artery diseases, it fails to provide essential hemodynamic parameters for early detection and treatment. These parameters can be easily obtained by performing computational fluid dynamic (CFD) analysis on the 3D artery geometry generated by CCTA image segmentation. As the coronary artery is small in size, manually segmenting the left coronary artery from CCTA scans is a laborious, time-intensive, error-prone, and complicated task which also requires a high level of expertise. Academics recently proposed various automated segmentation techniques for combatting these issues. To further aid in this process, we present CoronarySegNet, a deep learning-based framework, for autonomous and accurate segmentation as well as generation of 3D geometry of the left coronary artery. The design is based on the original U-net topology and includes channel-aware attention blocks as well as deep residual blocks with spatial dropout that contribute to feature map independence by eliminating 2D feature maps rather than individual components. We trained, tested, and statistically evaluated our model using CCTA images acquired from various medical centers across Bangladesh and the Rotterdam Coronary Artery Algorithm Evaluation challenge dataset to improve generality. In empirical assessment, CoronarySegNet outperforms several other cutting-edge segmentation algorithms, attaining dice similarity coefficient of 0.78 on an average while being highly significant (p < 0.05). Additionally, both the 3D geometries generated by machine learning and semi-automatic method were statistically similar. Moreover, hemodynamic evaluation performed on these 3D geometries showed comparable results.
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Hossain T, Anan N, Arafat MT. The effects of plaque morphological characteristics on the post-stenotic flow in left main coronary artery bifurcation. Biomed Phys Eng Express 2021; 7. [PMID: 34425569 DOI: 10.1088/2057-1976/ac202c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 08/23/2021] [Indexed: 12/13/2022]
Abstract
Local post-stenotic hemodynamics has critical influence in the atherosclerotic plaque progression occurring in susceptible arterial sites, in particular the left main coronary artery (LMCA) bifurcation. Understanding the effects of plaque morphological characteristics: stenosis severity (SS), eccentricity index (EI) and lesion length (LL) on the post-stenotic flow behavior can significantly improve treatment planning. In order to investigate these effects, we have employed computational fluid dynamics (CFD) simulations in twenty computer-generated and five patient-specific LMCA models and the hemodynamic parameters: velocity, pressure (P), wall pressure gradient (WPG), wall shear stress (WSS), time averaged wall shear stress (TAWSS), oscillatory shear index (OSI), relative residence time (RRT) and helicity intensity (h2) were analyzed. Our results revealed that the effect of stenosis eccentricity varied significantly for different values of stenosis severity and lesion length. Regions with low WSS, low TAWSS and high RRT were more prominent in models having higher stenosis severity. For smaller lesion length, at low and moderate stenosis severity, surface area with low TAWSS and high RRT decreased with increasing eccentricity index, whereas for high stenosis severity models, low TAWSS region and average RRT values increased with eccentricity. However, for models with longer lesion length, regions with high OSI and RRT overall increased gradually with eccentricity. The helicity intensity (h2) of all models remained very low except at the most eccentric model with longer lesion length. The presence of very high helical flow in this model suggests the possibility of atheroprotective flow. It can be concluded that all plaque morphological characteristics covered under this investigation play an important role in plaque progression.
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Affiliation(s)
- Tahura Hossain
- Department of Biomedical Engineering, Military Institute of Science and Technology (MIST), Dhaka-1216, Bangladesh
| | - Noushin Anan
- Department of Biomedical Engineering, Military Institute of Science and Technology (MIST), Dhaka-1216, Bangladesh
| | - M Tarik Arafat
- Department of Biomedical Engineering, Bangladesh University of Engineering and Technology (BUET), Dhaka-1205, Bangladesh
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Xiong Z, Yuan D, Wang J, Zheng T, Fan Y. Influence of renal artery stenosis morphology on hemodynamics. Comput Methods Biomech Biomed Engin 2021; 24:1294-1301. [PMID: 33565336 DOI: 10.1080/10255842.2021.1883592] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE Currently, the clinical classification of the severity of renal artery stenosis (RAS) solely depends on the degree of stenosis. In addition, when the stenosis degree is between 50% and 70%, the clinical strategy is decided based on whether the RAS is hemodynamically significant. In this study, the influence of RAS morphological parameters on hemodynamics was numerically analyzed to provide a theoretical basis for clinical treatment. METHODS Idealized RAS models were established to investigate the hemodynamic effects of the stenosis length, asymmetric stenosis, and direction of the opening of the renal artery. RESULTS The longer the stenosis length, the greater is the ratio of the low time-averaged wall shear stress (WSS) and high oscillatory shear index (OSI) area distal stenosis (when the stenosis area is the same). In addition, asymmetric stenosis leads to a significant increase in the ratio of the renal artery peak systolic velocity (R-PSV) and the abdominal aorta peak systolic velocity (A-PSV) when the stenosis area is 60-70%. Furthermore, the fraction flow reserve (FFR) of the RAS model with 12 mm stenosis length, upward eccentricity and upward direction of renal artery opening was approximately equal to the cumulative value of the influence of different stenosis morphologies on FFR. CONCLUSION An assessment of the severity of RAS should consider the stenosis area and other morphological parameters, including the length and asymmetry of RAS as well as the direction of the opening of renal artery, particularly when the stenosis degree of RAS is between 50% and 70%.
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Affiliation(s)
- Zhuxiang Xiong
- Department of Applied Mechanics, Sichuan University, Chengdu, China
| | - Ding Yuan
- Department of Vascular Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Jiarong Wang
- Department of Vascular Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Tinghui Zheng
- Department of Applied Mechanics, Sichuan University, Chengdu, China
| | - Yubo Fan
- Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang University, Beijing
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Alizadehghobadi S, Biglari H, Niroomand-Oscuii H, Matin MH. Numerical study of hemodynamics in a complete coronary bypass with venous and arterial grafts and different degrees of stenosis. Comput Methods Biomech Biomed Engin 2020; 24:883-896. [PMID: 33307817 DOI: 10.1080/10255842.2020.1857744] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Cardiovascular diseases are among the leading causes of death in the world. The coronary blockage is one of most common types of these diseases that in the majority of cases has been treated by bypass surgery. In the bypass surgery, a graft is implemented to alter the blocked coronary and allow the blood supply process. The hemodynamic characteristics of the bypass strongly depend on the geometry and mechanical properties of the graft. In the present study, the fluid-structure interaction (FSI) analysis is conducted to investigate the bypass performance for a thoracic artery as well as a saphenous vein graft. Blood flow introduces a pressure on the walls of the graft which behaves as a hyperelastic material. A complete coronary bypass with stenosis degrees of 70% and 100% is modeled. To consider the nonlinear stress-strain behavior of the grafts, a five parameter Mooney-Rivlin hyperplastic model is implemented for the structural analysis and blood is assumed to behave as a Newtonian fluid. The simulations are performed for a structured grid to solve the governing equations using finite element method (FEM). The results show that wall shear stress (WSS) for saphenous vein is larger than that of thoracic artery while the total deformation of the thoracic artery is larger compared to the saphenous vein. Also, for the venous grafts or lower stenosis degree, the oscillatory shear index (OSI) is higher at both left and right anastomoses meaning that venous grafts as well as lower degree of stenosis are more critical in terms of restenosis.
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Affiliation(s)
| | - Hasan Biglari
- Department of Mechanical Engineering, University of Tabriz, Tabriz, Iran
| | | | - Meisam H Matin
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL, USA
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Zuin M, Rigatelli G, Vassilev D, Ronco F, Rigatelli A, Roncon L. Computational fluid dynamic-derived wall shear stress of non-significant left main bifurcation disease may predict acute vessel thrombosis at 3-year follow-up. Heart Vessels 2020; 35:297-306. [PMID: 31482218 DOI: 10.1007/s00380-019-01494-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 08/23/2019] [Indexed: 02/07/2023]
Abstract
Wall shear stress (WSS) plays a pivotal role on plaque progression in coronary artery disease. We assess the prognostic role of baseline mean WSS in developing a bifurcation-located myocardial infarction (B-MI) over the following 3 years in angiographically non-significant LM bifurcation disease. For this purpose, we retrospectively reviewed the procedural and medical records of consecutive patients evaluated in our center from 1st January 2014 to 1st January 2019 who had a non-significant LM bifurcation disease as evaluated at coronary computed tomography angiography (CCTA) and confirmed by coronary angiography. Each bifurcation model was reconstructed on the patient-specific geometries derived from the CCTA. The population was divided into two groups: patients with (n = 12) and without B-MI (n = 20) over the following 3 years. Both the mean WSSprox of each branch and the WSSentire_lesion of each vessel, adjusted for the respective mean lesions lengths and 3-dimensional percentage of stenosis (DS%), resulted in independent predictors of 3-year B-MI. Multivariate Cox-regression analysis confirmed that a baseline mean WSSentire_model ≥ 5.05 Pa (HR 1.98, 95% CI 1.83-2.10, p = 0.001) was a predictor of 3-year B-MI independently from the entire mean lesions lengths (HR 1.56. 95% CI 1.43.1.68, p = 0.002) and DS% (HR 1.26, 95% CI 1.18-1.37, p = 0.03). In conclusion, in patients with angiographically non-significant LM bifurcation disease, both the mean WSSprox of each branch and WSSentire_lesion of each stenotic vessel predicted the occurrence of B-MI over the following 3 years. Moreover, the WSSentire_bifurcation ≥ 5.05 Pa seems to be a predictor of 3-year B-MI independently from the DS% and lesions lengths.
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Affiliation(s)
- Marco Zuin
- Section of Internal and Cardiopulmonary Medicine, Faculty of Medicine, University of Ferrara, Ferrara, Italy
- Division of Cardiology, Santa Maria Della Misericordia Hospital, Rovigo, Italy
| | - Gianluca Rigatelli
- Department of Cardiovascular Diagnosis and Endoluminal Interventions, Santa Maria Della Misericordia Hospital, Viale Tre Martiri, 45100, Rovigo, Italy.
| | - Dobrin Vassilev
- "Alexandrovska" University Hospital, Medical University, Sofia, Bulgaria
| | - Federico Ronco
- Interventional Cardiology, Cardiology Department, Mestre General Hospital, Mestre, Italy
| | - Alberto Rigatelli
- Department of Emergency, Borgo Trento University Hospital, Verona, Italy
| | - Loris Roncon
- Division of Cardiology, Santa Maria Della Misericordia Hospital, Rovigo, Italy
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Computational analysis of the coronary artery hemodynamics with different anatomical variations. INFORMATICS IN MEDICINE UNLOCKED 2020. [DOI: 10.1016/j.imu.2020.100314] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Transfer of Low-Density Lipoproteins in Coronary Artery Bifurcation Lesions with Stenosed Side Branch: Numerical Study. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2019; 2019:5297284. [PMID: 31737085 PMCID: PMC6815532 DOI: 10.1155/2019/5297284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 07/08/2019] [Accepted: 08/04/2019] [Indexed: 11/17/2022]
Abstract
Evidence from clinical data suggests that the stenotic side branch (SB) is one of the key predictors for SB occlusion-based adverse events. In this study, we hypothesized that coronary bifurcations with stenotic SB might lead to severe concentration polarization of atherogenic lipids, such as the low-density lipoproteins (LDL), motivating the adverse events in the clinic. To confirm this hypothesis, this work numerically investigated the transport of LDL in different bifurcation lesions based on the Medina classification with various location and stenosis severities. The results showed that the coronary bifurcations with stenotic SB might be suffering more serious concentration polarization of LDL on the luminal surface of the SB due to higher level of LDL concentrations. Moreover, compared to the other bifurcation lesion types, the type (1,0,1) had the highest luminal surface LDL concentration along the SB and the highest degree of risk to enhance the process of atherosclerosis. In addition, this study also showed that the luminal surface LDL concentration increased with elevated stenosis severity. The type (1,0,1) with the severe stenosis (75% diameter reduction) had the highest concentration at the SB. In conclusion, these results suggested that both location of lesions and stenosis severities had great influence on the distribution of LDL on the luminal surface of the SB. Therefore, the estimation of disease severity and the interventional therapy should be carried out not only according to the stenosis severities in clinic. Moreover, compared to the other bifurcation lesion types, the type (1,0,1), rather than the type (1,1,1) as usually considered, had the highest luminal surface LDL concentration along the SB and the highest degree of risk to enhance the process of atherosclerosis.
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Kamangar S, Salman Ahmed N, Badruddin IA, Al-Rawahi N, Husain A, Govindaraju K, Yunus Khan T. Effect of stenosis on hemodynamics in left coronary artery based on patient-specific CT scan. Biomed Mater Eng 2019; 30:463-473. [DOI: 10.3233/bme-191067] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Rigatelli G, Zuin M, Dell’Avvocata F, Nguyen T. Rheolytic effects of left main mid-shaft/distal stenting: a computational flow dynamic analysis. Ther Adv Cardiovasc Dis 2018; 12:161-168. [PMID: 29589515 PMCID: PMC5956950 DOI: 10.1177/1753944718765734] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 02/12/2018] [Indexed: 11/16/2022] Open
Abstract
Background The aim of this study was to evaluate the rheolytic effects of stenting a mid-shaft/distal left main coronary artery (LMCA) lesion with and without ostial coverage. Stenting of the LMCA has emerged as a valid alternative in place of traditional coronary bypass graft surgery. However, in case of mid-shaft/distal lesion, there is no consensus regarding the extension of the strut coverage up to the ostium or to stent only the culprit lesion. Methods We reconstructed a left main-left descending coronary artery (LM-LCA)-left circumflex (LCX) bifurcation after analysing 100 consecutive patients (mean age 71.4 ± 9.3, 49 males) with LM mid-shaft/distal disease. The mean diameter of proximal LM, left anterior descending (LAD) and LCX, evaluated with quantitative coronary angiography (QCA) was 4.62 ± 0.86 mm, 3.31 ± 0.92 mm, and 2.74 ± 0.93 mm, respectively. For the stent simulation, a third-generation, everolimus-eluting stent was virtually reconstructed. Results After virtual stenting, the net area averaged wall shear stress (WSS) of the model and the WSS at the LCA-LCX bifurcation resulted higher when the stent covered the culprit mid-shaft lesion only compared with the extension of the stent covering the ostium (3.68 versus 2.06 Pa, p = 0.01 and 3.97 versus 1.98 Pa, p < 0.001, respectively. Similarly, the static pressure and the Reynolds number were significantly higher after stent implantation covering up the ostium. At the ostium, the flow resulted more laminar when stenting only the mid-shaft lesion than including the ostium. Conclusions Although these findings cannot be translated directly into real practice our brief study suggests that stenting lesion 1:1 or extending the stent to cover the LM ostium impacts differently the rheolytic properties of LMCA bifurcation with potential insights for restenosis or thrombosis.
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Affiliation(s)
- Gianluca Rigatelli
- Ospedale Santa Maria della Misericordia, Via Tre Martiri 140, Rovigo, 45100, Italy
| | - Marco Zuin
- Ospedale Santa Maria della Misericordia, Rovigo, Italy
| | | | - Thach Nguyen
- Department of Cardiology, St Mary Medical Center, Hobart, Indiana, USA
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Kamangar S, Badruddin IA, Ameer Ahamad N, Soudagar MEM, Govindaraju K, Nik-Ghazali N, Salman Ahmed N, Yunus Khan T. Patient specific 3-d modeling of blood flow in a multi-stenosed left coronary artery. Biomed Mater Eng 2017; 28:257-266. [DOI: 10.3233/bme-171672] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Sarfaraz Kamangar
- Department of Mechanical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Irfan Anjum Badruddin
- Department of Mechanical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - N. Ameer Ahamad
- Mathematics Department, Faculty of Science, University of Tabuk, Saudi Arabia
| | | | - Kalimuthu Govindaraju
- Department of Mechanical and Industrial Engineering, Mekelle University, Mekelle, Ethiopia
| | - N. Nik-Ghazali
- Department of Mechanical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - N.J. Salman Ahmed
- Department of Mechanical and Industrial Engineering, Sultan Qaboos University, Al Khoud, Muscat, 123, Oman
| | - T.M. Yunus Khan
- Department of Mechanical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia
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Pagiatakis C, Tardif JC, L'Allier PL, Mongrain R. Effect of stenosis eccentricity on the functionality of coronary bifurcation lesions-a numerical study. Med Biol Eng Comput 2017; 55:2079-2095. [PMID: 28500478 DOI: 10.1007/s11517-017-1653-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 04/25/2017] [Indexed: 01/10/2023]
Abstract
Interventional cardiologists still rely heavily on angiography for the evaluation of coronary lesion severity, despite its poor correlation with the presence of ischemia. In order to improve the accuracy of the current diagnostic procedures, an understanding of the relative influence of geometric characteristics on the induction of ischemia is required. This idea is especially important for coronary bifurcation lesions (CBLs), whose treatment is complex and is associated with high rates of peri- and post-procedural clinical events. Overall, it is unclear which geometric and morphological parameters of CBLs influence the onset of ischemia. More specifically, the effect of stenosis eccentricity is unknown. Computational fluid dynamic simulations, under a geometric multiscale framework, were executed for seven CBL configurations within the left main coronary artery bifurcation. Both concentric and eccentric stenosis profiles of mild to severe constriction were considered. By using a geometric multiscale framework, the fractional flow reserve, which is the gold-standard clinical diagnostic index, could be calculated and was compared between the eccentric and concentric profiles for each case. The results suggested that for configurations where the supplying vessel is stenosed, eccentricity could have a notable effect on and therefore be an important factor that influences configuration functionality.
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Affiliation(s)
- Catherine Pagiatakis
- Department of Mechanical Engineering, McGill University, 817 Sherbrooke Street West, Montreal, Quebec, H3A 0C3, Canada. .,Montreal Heart Institute, 5000 Belanger Street, Montreal, Quebec, H1T 1C8, Canada.
| | - Jean-Claude Tardif
- Montreal Heart Institute, 5000 Belanger Street, Montreal, Quebec, H1T 1C8, Canada.,Faculty of Medicine, Université de Montréal - Pavillon Roger-Gaudry, 2900 Edouard-Montpetit Boulevard, Montreal, Quebec, H3T 1J4, Canada
| | - Philippe L L'Allier
- Montreal Heart Institute, 5000 Belanger Street, Montreal, Quebec, H1T 1C8, Canada.,Faculty of Medicine, Université de Montréal - Pavillon Roger-Gaudry, 2900 Edouard-Montpetit Boulevard, Montreal, Quebec, H3T 1J4, Canada
| | - Rosaire Mongrain
- Department of Mechanical Engineering, McGill University, 817 Sherbrooke Street West, Montreal, Quebec, H3A 0C3, Canada.,Montreal Heart Institute, 5000 Belanger Street, Montreal, Quebec, H1T 1C8, Canada
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Liu D, Liu J, Wen Z, Li Y, Sun Z, Xu Q, Fan Z. 320-row CT renal perfusion imaging in patients with aortic dissection: A preliminary study. PLoS One 2017; 12:e0171235. [PMID: 28182709 PMCID: PMC5300209 DOI: 10.1371/journal.pone.0171235] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 01/17/2017] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE To investigate the clinical value of renal perfusion imaging in patients with aortic dissection (AD) using 320-row computed tomography (CT), and to determine the relationship between renal CT perfusion imaging and various factors of aortic dissection. METHODS Forty-three patients with AD who underwent 320-row CT renal perfusion before operation were prospectively enrolled in this study. Diagnosis of AD was confirmed by transthoracic echocardiography. Blood flow (BF) of bilateral renal perfusion was measured and analyzed. CT perfusion imaging signs of AD in relation to the type of AD, number of entry tears and the false lumen thrombus were observed and compared. RESULTS The BF values of patients with type A AD were significantly lower than those of patients with type B AD (P = 0.004). No significant difference was found in the BF between different numbers of intimal tears (P = 0.288), but BF values were significantly higher in cases with a false lumen without thrombus and renal arteries arising from the true lumen than in those with thrombus (P = 0.036). The BF values measured between the true lumen, false lumen and overriding groups were different (P = 0.02), with the true lumen group having the highest. Also, the difference in BF values between true lumen and false lumen groups was statistically significant (P = 0.016), while no statistical significance was found in the other two groups (P > 0.05). The larger the size of intimal entry tears, the greater the BF values (P = 0.044). CONCLUSIONS This study shows a direct correlation between renal CT perfusion changes and AD, with the size, number of intimal tears, different types of AD, different renal artery origins and false lumen thrombosis, significantly affecting the perfusion values.
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Affiliation(s)
- Dongting Liu
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Jiayi Liu
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Zhaoying Wen
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Yu Li
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Zhonghua Sun
- Department of Medical Radiation Sciences, Curtin University, Perth, Australia
| | - Qin Xu
- School of Public Health, Capital Medical University, Beijing, China
| | - Zhanming Fan
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
- * E-mail:
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Kamangar S, Badruddin IA, Badarudin A, Nik-Ghazali N, Govindaraju K, Salman Ahmed NJ, Yunus Khan TM. Influence of stenosis on hemodynamic parameters in the realistic left coronary artery under hyperemic conditions. Comput Methods Biomech Biomed Engin 2016; 20:365-372. [DOI: 10.1080/10255842.2016.1233402] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Sarfaraz Kamangar
- Department of Mechanical Engineering, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - Irfan Anjum Badruddin
- Department of Mechanical Engineering, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - A. Badarudin
- Department of Mechanical Engineering, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - N. Nik-Ghazali
- Department of Mechanical Engineering, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - Kalimuthu Govindaraju
- Department of Mechanical Engineering, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - N. J. Salman Ahmed
- Center for Energy Sciences, Department of Mechanical Engineering, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - T. M. Yunus Khan
- Department of Mechanical Engineering, University of Malaya, Kuala Lumpur, 50603, Malaysia
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Doutel E, Pinto SIS, Campos JBLM, Miranda JM. Link between deviations from Murray's Law and occurrence of low wall shear stress regions in the left coronary artery. J Theor Biol 2016; 402:89-99. [PMID: 27157126 DOI: 10.1016/j.jtbi.2016.04.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 04/22/2016] [Accepted: 04/29/2016] [Indexed: 11/28/2022]
Abstract
Murray developed two laws for the geometry of bifurcations in the circulatory system. Based on the principle of energy minimization, Murray found restrictions for the relation between the diameters and also between the angles of the branches. It is known that bifurcations are prone to the development of atherosclerosis, in regions associated to low wall shear stresses (WSS) and high oscillatory shear index (OSI). These indicators (size of low WSS regions, size of high OSI regions and size of high helicity regions) were evaluated in this work. All of them were normalized by the size of the outflow branches. The relation between Murray's laws and the size of low WSS regions was analysed in detail. It was found that the main factor leading to large regions of low WSS is the so called expansion ratio, a relation between the cross section areas of the outflow branches and the cross section area of the main branch. Large regions of low WSS appear for high expansion ratios. Furthermore, the size of low WSS regions is independent of the ratio between the diameters of the outflow branches. Since the expansion ratio in bifurcations following Murray's law is kept in a small range (1 and 1.25), all of them have regions of low WSS with similar size. However, the expansion ratio is not small enough to completely prevent regions with low WSS values and, therefore, Murray's law does not lead to atherosclerosis minimization. A study on the effect of the angulation of the bifurcation suggests that the Murray's law for the angles does not minimize the size of low WSS regions.
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Affiliation(s)
- E Doutel
- Centro de Estudos de Fenómenos de Transporte, Departamento de Engenharia Química, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - S I S Pinto
- Centro de Estudos de Fenómenos de Transporte, Departamento de Engenharia Química, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - J B L M Campos
- Centro de Estudos de Fenómenos de Transporte, Departamento de Engenharia Química, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - J M Miranda
- Centro de Estudos de Fenómenos de Transporte, Departamento de Engenharia Química, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
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Javadzadegan A, Yong ASC, Chang M, Ng MKC, Behnia M, Kritharides L. Haemodynamic assessment of human coronary arteries is affected by degree of freedom of artery movement. Comput Methods Biomech Biomed Engin 2016; 20:260-272. [DOI: 10.1080/10255842.2016.1215439] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Pagiatakis C, Tardif JC, L’Allier PL, Mongrain R. A numerical investigation of the functionality of coronary bifurcation lesions with respect to lesion configuration and stenosis severity. J Biomech 2015; 48:3103-11. [DOI: 10.1016/j.jbiomech.2015.07.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 07/15/2015] [Accepted: 07/18/2015] [Indexed: 10/23/2022]
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17
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Wang H, Liu J, Zheng X, Rong X, Zheng X, Peng H, Silber-Li Z, Li M, Liu L. Three-dimensional virtual surgery models for percutaneous coronary intervention (PCI) optimization strategies. Sci Rep 2015; 5:10945. [PMID: 26042609 PMCID: PMC4455241 DOI: 10.1038/srep10945] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 05/11/2015] [Indexed: 12/03/2022] Open
Abstract
Percutaneous coronary intervention (PCI), especially coronary stent implantation, has been shown to be an effective treatment for coronary artery disease. However, in-stent restenosis is one of the longstanding unsolvable problems following PCI. Although stents implanted inside narrowed vessels recover normal flux of blood flows, they instantaneously change the wall shear stress (WSS) distribution on the vessel surface. Improper stent implantation positions bring high possibilities of restenosis as it enlarges the low WSS regions and subsequently stimulates more epithelial cell outgrowth on vessel walls. To optimize the stent position for lowering the risk of restenosis, we successfully established a digital three-dimensional (3-D) model based on a real clinical coronary artery and analysed the optimal stenting strategies by computational simulation. Via microfabrication and 3-D printing technology, the digital model was also converted into in vitro microfluidic models with 3-D micro channels. Simultaneously, physicians placed real stents inside them; i.e., they performed “virtual surgeries”. The hydrodynamic experimental results showed that the microfluidic models highly inosculated the simulations. Therefore, our study not only demonstrated that the half-cross stenting strategy could maximally reduce restenosis risks but also indicated that 3-D printing combined with clinical image reconstruction is a promising method for future angiocardiopathy research.
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Affiliation(s)
- Hujun Wang
- Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China.,Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jinghua Liu
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Disease, Beijing 100029, China
| | - Xu Zheng
- State key laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaohui Rong
- Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xuwei Zheng
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Disease, Beijing 100029, China
| | - Hongyu Peng
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Disease, Beijing 100029, China
| | - Zhanghua Silber-Li
- State key laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China
| | - Mujun Li
- Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Liyu Liu
- Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
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Frattolin J, Zarandi MM, Pagiatakis C, Bertrand OF, Mongrain R. Numerical study of stenotic side branch hemodynamics in true bifurcation lesions. Comput Biol Med 2015; 57:130-8. [DOI: 10.1016/j.compbiomed.2014.11.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 11/19/2014] [Accepted: 11/28/2014] [Indexed: 11/15/2022]
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19
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Sun Z, Xu L. Computational fluid dynamics in coronary artery disease. Comput Med Imaging Graph 2014; 38:651-63. [PMID: 25262321 DOI: 10.1016/j.compmedimag.2014.09.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Revised: 08/22/2014] [Accepted: 09/03/2014] [Indexed: 01/01/2023]
Abstract
Computational fluid dynamics (CFD) is a widely used method in mechanical engineering to solve complex problems by analysing fluid flow, heat transfer, and associated phenomena by using computer simulations. In recent years, CFD has been increasingly used in biomedical research of coronary artery disease because of its high performance hardware and software. CFD techniques have been applied to study cardiovascular haemodynamics through simulation tools to predict the behaviour of circulatory blood flow in the human body. CFD simulation based on 3D luminal reconstructions can be used to analyse the local flow fields and flow profiling due to changes of coronary artery geometry, thus, identifying risk factors for development and progression of coronary artery disease. This review aims to provide an overview of the CFD applications in coronary artery disease, including biomechanics of atherosclerotic plaques, plaque progression and rupture; regional haemodynamics relative to plaque location and composition. A critical appraisal is given to a more recently developed application, fractional flow reserve based on CFD computation with regard to its diagnostic accuracy in the detection of haemodynamically significant coronary artery disease.
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Affiliation(s)
- Zhonghua Sun
- Discipline of Medical Imaging, Department of Imaging and Applied Physics, Curtin University, Perth, Western Australia 6845, Australia.
| | - Lei Xu
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
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20
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ZHAN FAN, CHEN ZENGSHENG, DENG XIAOYAN. SWIRLING FLOW CAN SUPPRESS MONOCYTES ADHESION IN END-TO-END ARTERIAL ANASTOMOSIS. J MECH MED BIOL 2014. [DOI: 10.1142/s0219519414500808] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
To test the hypothesis that the monocytes adhesion would be suppressed by intentionally inducing swirling flow in end-to-end arterial anastomosis to inhibit the flow disturbance, the comparing experimental and numerical investigation under both normal flow condition and swirling flow condition were executed, in which the sudden expanded tube and U-937 cells were used. The numerical results reveal that, comparing to normal flow, the swirling flow could reduce the size of flow disturbed zones and enhance the wall shear stress (WSS) in the closed downstream of sudden expanded tube. The experimental results show that there are disturbed flow zones in the sudden expanded tube, where the adhesion number of U-937 cells is larger than other zones. More importantly, comparing to the normal flow, the swirling flow could reduce the adhesion of U-937 cells, in which the adhesion number become smaller with the increasing of the swirling intensity. Therefore, the present study suggests that intentionally introducing swirling flow in end-to-end arterial anastomosis may be a solution to solve the problem of intimal hyperplasia (IH) by suppressing the flow disturbance and restraining the adhesion of monocytes to keep the favorably unimpeded flow.
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Affiliation(s)
- FAN ZHAN
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science & Medical Engineering, Beihang University, Beijing 100191, P. R. China
| | - ZENGSHENG CHEN
- Department of Engineering Mechanics, School of Aerospace, Tsinghua University, 100084 Beijing, P. R. China
| | - XIAOYAN DENG
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science & Medical Engineering, Beihang University, Beijing 100191, P. R. China
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21
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Sun Z. Coronary CT angiography: Beyond morphological stenosis analysis. World J Cardiol 2013; 5:444-452. [PMID: 24392188 PMCID: PMC3879698 DOI: 10.4330/wjc.v5.i12.444] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 10/04/2013] [Accepted: 11/19/2013] [Indexed: 02/06/2023] Open
Abstract
Rapid technological developments in computed tomography (CT) imaging technique have made coronary CT angiography an attractive imaging tool in the detection of coronary artery disease. Despite visualization of excellent anatomical details of the coronary lumen changes, coronary CT angiography does not provide hemodynamic changes caused by presence of plaques. Computational fluid dynamics (CFD) is a widely used method in the mechanical engineering field to solve complex problems through analysing fluid flow, heat transfer and associated phenomena by using computer simulations. In recent years, CFD is increasingly used in biomedical research due to high performance hardware and software. CFD techniques have been used to study cardiovascular hemodynamics through simulation tools to assist in predicting the behaviour of circulatory blood flow inside the human body. Blood flow plays a key role in the localization and progression of coronary artery disease. CFD simulation based on 3D luminal reconstructions can be used to analyse the local flow fields and flow profiling due to changes of vascular geometry, thus, identifying risk factors for development of coronary artery disease. The purpose of this article is to provide an overview of the coronary CT-derived CFD applications in coronary artery disease.
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22
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Haemodynamic analysis of the effect of different types of plaques in the left coronary artery. Comput Med Imaging Graph 2013; 37:197-206. [DOI: 10.1016/j.compmedimag.2013.02.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 01/08/2013] [Accepted: 02/27/2013] [Indexed: 11/18/2022]
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Chaichana T, Sun Z, Jewkes J. Hemodynamic impacts of various types of stenosis in the left coronary artery bifurcation: a patient-specific analysis. Phys Med 2013; 29:447-52. [PMID: 23453845 DOI: 10.1016/j.ejmp.2013.02.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 02/06/2013] [Accepted: 02/11/2013] [Indexed: 12/18/2022] Open
Abstract
This study investigates the hemodynamic changes to various types of coronary stenosis in the left coronary artery bifurcation, based on a patient-specific analysis. Twenty two patients with left coronary artery disease were included in this study. All stenoses involving the left coronary artery bifurcation were classified into four types, according to their locations: A) left circumflex (LCx) and left anterior descending (LAD), B) LCx only, C) left main stem only, and D) LAD only. Computational fluid dynamics (CFD) was performed to analyze the flow and wall shear stress (WSS) changes in all reconstructed left coronary geometries. Our results showed that the flow velocity and WSS were significantly increased at stenotic locations. High WSS was found at >70% lumen stenosis, which ranged from 2.5 Pa to 3.5 Pa. This study demonstrates that in patients with more than 50% stenosis in the left coronary artery bifurcation, WSS plays an important role in providing information about the extent of coronary atherosclerosis in the left coronary artery branch.
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Affiliation(s)
- Thanapong Chaichana
- Discipline of Medical Imaging, Department of Imaging and Applied Physics, Curtin University, GPO Box, U1987, Perth, Western Australia 6845, Australia.
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