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Tripathy KC, Siddharth A, Bhandari A. Image-based insilico investigation of hemodynamics and biomechanics in healthy and diabetic human retinas. Microvasc Res 2023; 150:104594. [PMID: 37579814 DOI: 10.1016/j.mvr.2023.104594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 07/22/2023] [Accepted: 08/11/2023] [Indexed: 08/16/2023]
Abstract
Retinal hemodynamics and biomechanics play a significant role in understanding the pathophysiology of several ocular diseases. However, these parameters are significantly affected due to changed blood vessel morphology ascribed to pathological conditions, particularly diabetes. In this study, an image-based computational fluid dynamics (CFD) model is applied to examine the effects of changed vascular morphology due to diabetes on blood flow velocity, vorticity, wall shear stress (WSS), and oxygen distribution and compare it with healthy. The 3D patient-specific vascular architecture of diabetic and healthy retina is extracted from Optical Coherence Tomography Angiography (OCTA) images and fundus to extract the capillary level information. Further, Fluid-structure interaction (FSI) simulations have been performed to compare the induced tissue stresses in diabetic and healthy conditions. Results illustrate that most arterioles possess higher velocity, vorticity, WSS, and lesser oxygen concentration than arteries for healthy and diabetic cases. However, an opposite trend is observed for venules and veins. Comparisons show that, on average, the blood flow velocity in the healthy case decreases by 42 % in arteries and 21 % in veins, respectively, compared to diabetic. In addition, the WSS and von Mises stress (VMS) in healthy case decrease by 49 % and 72 % in arteries and by 6 % and 28 % in veins, respectively, when compared with diabetic, making diabetic blood vessels more susceptible to wall rupture and tissue damage. The in-silico results may help predict the possible abnormalities region early, helping the ophthalmologists use these estimates as prognostic tools and tailor patient-specific treatment plans.
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Affiliation(s)
- Kartika Chandra Tripathy
- Biofluids Research Lab, Department of Mechanical Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India
| | - Ashish Siddharth
- Biofluids Research Lab, Department of Mechanical Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India
| | - Ajay Bhandari
- Biofluids Research Lab, Department of Mechanical Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India.
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2
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Silva MLFDA, Gonçalves SDEF, Haniel J, Lucas TC, Huebner R. Comparative study between 1-way and 2-way coupled fluid-structure interaction in numerical simulation of aortic arch aneurysms. AN ACAD BRAS CIENC 2023; 95:e20210859. [PMID: 37255166 DOI: 10.1590/0001-3765202320210859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 12/19/2022] [Indexed: 06/01/2023] Open
Abstract
Hemodynamic forces are related to pathological variations of the cardiovascular system, and numerical simulations for fluid-structure interaction have been systematically used to analyze the behavior of blood flow and the arterial wall in aortic aneurysms. This paper proposes a comparative analysis of 1-way and 2-way coupled fluid-structure interaction for aortic arch aneurysm. The coupling models of fluid-structure interaction were conducted using 3D geometry of the thoracic aorta from computed tomography. Hyperelastic anisotropic properties were estimated for the Holzapfel arterial wall model. The rheological behavior of the blood was modeled by the Carreau-Yasuda model. The results showed that the 1-way approach tends to underestimate von Mises stress, displacement, and strain over the entire cardiac cycle, compared to the 2-way approach. In contrast, the behavior of the variables of flow field, velocity, wall shear stress, and Reynolds number when coupled by the 1-way model was overestimated at the systolic moment and tends to be equal at the diastolic moment. The quantitative differences found, especially during the systole, suggest the use of 2-way coupling in numerical simulations of aortic arch aneurysms due to the hyperelastic nature of the arterial wall, which leads to a strong iteration between the fluid and the arterial wall.
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Affiliation(s)
- Mário Luis F DA Silva
- Programa de Pós-Graduação em Engenharia Mecânica, Universidade Federal de Minas Gerais, Departamento de Engenharia Mecânica, Avenida Presidente Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brazil
| | - Saulo DE Freitas Gonçalves
- Programa de Pós-Graduação em Engenharia Mecânica, Universidade Federal de Minas Gerais, Departamento de Engenharia Mecânica, Avenida Presidente Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brazil
| | - Jonathas Haniel
- Programa de Pós-Graduação em Engenharia Mecânica, Universidade Federal de Minas Gerais, Departamento de Engenharia Mecânica, Avenida Presidente Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brazil
| | - Thabata C Lucas
- Programa de Pós-Graduação em Ciências da Saúde, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Departamento de Enfermagem, MGC 367, km 583, 5000, Alto da Jacuba, 39100-000 Diamantina, MG, Brazil
| | - Rudolf Huebner
- Universidade Federal de Minas Gerais, Departamento de Engenharia Mecânica, Avenida Presidente Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brazil
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3
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Domanin M, Bennati L, Vergara C, Bissacco D, Malloggi C, Silani V, Parati G, Trimarchi S, Casana R. Fluid structure interaction analysis to stratify the behavior of different atheromatous carotid plaques. THE JOURNAL OF CARDIOVASCULAR SURGERY 2023; 64:58-66. [PMID: 36106395 DOI: 10.23736/s0021-9509.22.12170-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND In asymptomatic carotid stenosis (ACS), different plaque types, i.e. lipidic (LP), fibrous (FP), and calcific (CP), could have different hemodynamic and structural behaviors. METHODS Different carotid plaques, reconstructed from medical imaging of ACS >70%, were analyzed by computing fluid structure interaction (FSI), modeling the spatial distribution of wall shear stresses (WSS), plaque displacements (D), von Mises stresses (VMS), and absorbed elastic energy (AEE) together with their maximum-in-space values at the systole (WSS<inf>syst</inf>, D<inf>syst</inf>, VMS<inf>syst</inf> and AEE<inf>syst</inf>). RESULTS WSS resulted significantly higher in CP, whereas D and VMS showed the highest values for LP. Regarding AEE<inf>syst</inf> stored by the plaques, LP absorbed in average 2320 J/m3, FP 408 J/m3 (470%) and CP 99 J/m3 (2240%), (P<0.01, P<0.01, and P<0.01, respectively). CONCLUSIONS Depending upon their nature, plaques store different deformations and inner distributions of forces, thus potentially influencing their vulnerability.
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Affiliation(s)
- Maurizio Domanin
- Dipartimento di Scienze Cliniche e di Comunità, Università degli Studi di Milano, Milan, Italy - .,Vascular Surgery Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy -
| | - Lorenzo Bennati
- Dipartimento di Scienze Chirurgiche Odontostomatologiche e Materno-Infantili, Università degli Studi di Verona, Verona, Italy
| | - Christian Vergara
- LABS, Dipartimento di Chimica, Materiali e Ingegneria Chimica "Giulio Natta", Politecnico di Milano, Milan, Italy
| | - Daniele Bissacco
- Dipartimento di Scienze Cliniche e di Comunità, Università degli Studi di Milano, Milan, Italy
| | - Chiara Malloggi
- Istituto Auxologico Italiano, IRCCS, Dipartimento di Neurologia e Stroke Unit e Laboratorio di Ricerche di Neuroscienze, Ospedale San Luca, Milan, Italy
| | - Vincenzo Silani
- Istituto Auxologico Italiano, IRCCS, Dipartimento di Neurologia e Stroke Unit e Laboratorio di Ricerche di Neuroscienze, Ospedale San Luca, Milan, Italy.,Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Centro 'Dino Ferrari', Università degli Studi di Milano, Milan, Italy
| | - Gianfranco Parati
- Istituto Auxologico Italiano, IRCCS, Dipartimento di Scienze Cardiovascolari, Neurologiche, Metaboliche, Ospedale San Luca, Milan, Italy.,Dipartimento di Medicina e Chirurgia, Università di Milano-Bicocca, Milan, Italy
| | - Santi Trimarchi
- Dipartimento di Scienze Cliniche e di Comunità, Università degli Studi di Milano, Milan, Italy.,Vascular Surgery Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Renato Casana
- Istituto Auxologico Italiano, IRCCS, Centro Chirurgia Vascolare, Auxologico Capitanio, Milan, Italy.,Istituto Auxologico Italiano, IRCCS, Laboratorio Sperimentale di Ricerche di Chirurgia Vascolare, Milan, Italy
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Chen B, Tao W, Li S, Zeng M, Zhang L, Huang Z, Chen F. Medial Gap: A Structural Factor at the Arterial Bifurcation Aggravating Hemodynamic Insult. J Neuropathol Exp Neurol 2022; 81:282-290. [PMID: 35312777 DOI: 10.1093/jnen/nlac017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Previous studies have reported that intracranial aneurysms frequently occur adjacent to the medial gap. However, the role of the medial gap in aneurysm formation is controversial. We designed this study to explore the potential role of the medial gap in aneurysm formation. Widened artery bifurcations with or without medial gaps were microsurgically created and pathologically stained in the carotid arteries of 30 rats. Numerical artery bifurcation models were constructed, and bidirectional fluid-solid interaction analyses were performed. Animal experiments showed that the apexes of widened bifurcations with a medial gap were prone to being insulted by blood flow compared to those without a medial gap. The bidirectional fluid-solid interaction analyses indicated that artery bifurcations with the medial gap exhibited higher wall shear stress (WSS) and von Mises stress (VMS) at the apex of the bifurcation. The disparity of stress between the gap and no-gap model was larger for widened bifurcations, peaking at 180° with a maximum of 1.9 folds. The maximum VMS and relatively high WSS were located at the junction between the medial gap and the adjacent arterial wall. Our results suggest that the medial gap at the widened arterial bifurcation may promote aneurysm formation.
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Affiliation(s)
- Bo Chen
- From the Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, Hunan, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Wengui Tao
- From the Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, Hunan, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Shifu Li
- From the Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, Hunan, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Ming Zeng
- From the Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, Hunan, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Liyang Zhang
- From the Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, Hunan, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zheng Huang
- From the Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, Hunan, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Fenghua Chen
- From the Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, Hunan, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
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5
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Cai Y, Li Z. Mathematical modeling of plaque progression and associated microenvironment: How far from predicting the fate of atherosclerosis? COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2021; 211:106435. [PMID: 34619601 DOI: 10.1016/j.cmpb.2021.106435] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 09/16/2021] [Indexed: 06/13/2023]
Abstract
Mathematical modeling contributes to pathophysiological research of atherosclerosis by helping to elucidate mechanisms and by providing quantitative predictions that can be validated. In turn, the complexity of atherosclerosis is well suited to quantitative approaches as it provides challenges and opportunities for new developments of modeling. In this review, we summarize the current 'state of the art' on the mathematical modeling of the effects of biomechanical factors and microenvironmental factors on the plaque progression, and its potential help in prediction of plaque development. We begin with models that describe the biomechanical environment inside and outside the plaque and its influence on its growth and rupture. We then discuss mathematical models that describe the dynamic evolution of plaque microenvironmental factors, such as lipid deposition, inflammation, smooth muscle cells migration and intraplaque hemorrhage, followed by studies on plaque growth and progression using these modelling approaches. Moreover, we present several key questions for future research. Mathematical models can complement experimental and clinical studies, but also challenge current paradigms, redefine our understanding of mechanisms driving plaque vulnerability and propose future potential direction in therapy for cardiovascular disease.
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Affiliation(s)
- Yan Cai
- School of Biological Sciences and Medical Engineering, Southeast University, Nanjing 210096, China.
| | - Zhiyong Li
- School of Biological Sciences and Medical Engineering, Southeast University, Nanjing 210096, China; School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, QLD 4001, Australia
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6
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Kuchumov AG, Vedeneev V, Samartsev V, Khairulin A, Ivanov O. Patient-specific fluid-structure interaction model of bile flow: comparison between 1-way and 2-way algorithms. Comput Methods Biomech Biomed Engin 2021; 24:1693-1717. [PMID: 34176396 DOI: 10.1080/10255842.2021.1910942] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Gallbladder disease is one of the most spread pathologies in the world. Despite the number of operations dealing with biliary surgery increases, the number of postoperative complications is also high. The aim of this study is to show the influence of the biliary system pathology on bile flow character and to numerically assess the effect of surgical operation (cholecystectomy) on the fluid dynamics in the extrahepatic biliary tree, and also to reveal the difference between 1-way and 2-way FSI algorithms on the results. Moreover, the bile viscosity and biliary tree geometry influence on the choledynamics were evaluated. Bile velocity, pressure, wall shear stress (WSS), displacements and von Mises stress distributions in the extrahepatic biliary tree are presented, and comparison is made between a healthy and a lithogenic bile. The patient-specific biliary tree model is created using magnetic resonance imaging (MRI) and imported in a commercial finite element analysis software. It is found that in the case of lithogenic bile, velocities have lower magnitude while pressures are higher. Furthermore, stress analysis of the bile ducts shows that the WSS distribution is found mostly prevailing in the common hepatic duct and common bile duct areas. It is shown that when it is necessary to evaluate the bile flow dynamics in urgent medical situations, 1-way analysis is acceptable. Nevertheless, 2-way FSI provides more accurate data, if necessary to evaluate the stress-strain state of bile ducts. The proposed model can be applied to medical practice to reduce the number of post-operative complications.
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Affiliation(s)
- Alex G Kuchumov
- Department of Computational Mathematics, Mechanics, and Biomechanics, Perm National Research Polytechnic University, Perm, Russian Federation.,Mathematical Center, Kazan Federal University, Kazan, Russian Federation
| | - Vasily Vedeneev
- Steklov Mathematical Institute of Russian Academy of Sciences, Moscow, Russian Federation.,Institute of Mechanics, Moscow, Russian Federation
| | - Vladimir Samartsev
- Department of General Surgery, Perm State Medical University, Perm, Russian Federation
| | - Aleksandr Khairulin
- Department of Computational Mathematics, Mechanics, and Biomechanics, Perm National Research Polytechnic University, Perm, Russian Federation
| | - Oleg Ivanov
- Institute of Mechanics of Moscow State University, Moscow, Russian Federation
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7
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Bennati L, Vergara C, Domanin M, Malloggi C, Bissacco D, Trimarchi S, Silani V, Parati G, Casana R. A Computational Fluid-Structure Interaction Study for Carotids With Different Atherosclerotic Plaques. J Biomech Eng 2021; 143:1107993. [PMID: 33876184 DOI: 10.1115/1.4050910] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Indexed: 11/08/2022]
Abstract
Atherosclerosis is a systemic disease that leads to accumulation of deposits, known as atherosclerotic plaques, within the walls of the carotids. In particular, three types of plaque can be distinguished: soft, fibrous, and calcific. Most of the computational studies who investigated the interplay between the plaque and the blood flow on patient-specific geometries used nonstandard medical images to directly delineate and segment the plaque and its components. However, these techniques are not so widely available in the clinical practice. In this context, the aim of our work was twofold: (i) to propose a new geometric tool that allowed to reconstruct a plausible plaque in the carotids from standard images and (ii) to perform three-dimensional (3D) fluid-structure interaction (FSI) simulations where we compared some fluid-dynamic and structural quantities among 15 patients characterized by different typologies of plaque. Our results highlighted that both the morphology and the mechanical properties of different plaque components play a crucial role in determining the vulnerability of the plaque.
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Affiliation(s)
- Lorenzo Bennati
- Department of Surgery, Dentistry, Paediatrics and Gynaecology, University of Verona, Verona 37129, Italy
| | - Christian Vergara
- LABS, Dipartimento di Chimica, Materiali e Ingegneria Chimica "Giulio Natta," Politecnico di Milano, Milan 20133, Italy
| | - Maurizio Domanin
- Vascular Surgery Unit, IRCCS, Ospedale Maggiore Policlinico, Milan 20133, Italy; Department of Clinical Sciences and Community Health, University of Milan, Milan 20133, Italy
| | - Chiara Malloggi
- Laboratory of Research in Vascular Surgery, Istituto Auxologico Italiano, IRCCS, Milan 20133, Italy
| | - Daniele Bissacco
- Vascular Surgery Unit, IRCCS, Ospedale Maggiore Policlinico, Milan 20133, Italy
| | - Santi Trimarchi
- Vascular Surgery Unit, IRCCS, Ospedale Maggiore Policlinico, Milan 20133, Italy; Department of Clinical Sciences and Community Health, University of Milan, Milan 20133, Italy
| | - Vincenzo Silani
- Department of Neurology-Stroke Unit and Laboratory of Neuroscience, Ospedale San Luca, Istituto Auxologico Italiano, IRCCS, Milan 20133, Italy; Department of Pathophysiology and Transplantation, University of Milan, Milan 20133, Italy
| | - Gianfranco Parati
- Department of Cardiovascular, Neural and Metabolic Sciences, Ospedale San Luca, Istituto Auxologico Italiano, IRCCS, Milan 20133, Italy; Department of Medicine and Surgery, Università di Milano-Bicocca, Monza 20900, Italy
| | - Renato Casana
- Laboratory of Research in Vascular Surgery, Istituto Auxologico Italiano, IRCCS, Milan 20133, Italy; Department of Surgery, Istituto Auxologico Italiano, IRCCS, Milan 20133, Italy
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8
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Pozzi S, Domanin M, Forzenigo L, Votta E, Zunino P, Redaelli A, Vergara C. A surrogate model for plaque modeling in carotids based on Robin conditions calibrated by cine MRI data. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2021; 37:e3447. [PMID: 33586336 DOI: 10.1002/cnm.3447] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 12/05/2020] [Accepted: 12/07/2020] [Indexed: 06/12/2023]
Abstract
We propose a surrogate model for the fluid-structure interaction (FSI) problem for the study of blood dynamics in carotid arteries in presence of plaque. This is based on the integration of a numerical model with subject-specific data and clinical imaging. We propose to model the plaque as part of the tissues surrounding the vessel wall through the application of an elastic support boundary condition. In order to characterize the plaque and other surrounding tissues, such as the close-by jugular vein, the elastic parameters of the boundary condition were spatially differentiated and their values were estimated by minimizing the discrepancies between computed vessel displacements and reference values obtained from CINE Magnetic Resonance Imaging data. We applied the model to three subjects with a degree of stenosis greater than 70%. We found that accounting for both plaque and jugular vein in the estimation of the elastic parameters increases the accuracy. In particular, in all patients, mismatches between computed and in vivo measured wall displacements were one to two orders of magnitude lower than the spatial resolution of the original MRI data. These results confirmed the validity of the proposed surrogate plaque model. We also compared fluid-dynamics results with those obtained in a fixed wall setting and in a full FSI model, used as gold standard, highlighting the better accordance of our results in comparison to the rigid ones.
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Affiliation(s)
- Silvia Pozzi
- MOX, Department of Mathematics, Politecnico di Milano, Milan, Italy
| | - Maurizio Domanin
- Department of Clinical Sciences and Community Health, Università di Milano, Milan, Italy
- Unità Operativa di Chirurgia Vascolare, Fondazione I.R.C.C.S. Cà Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Laura Forzenigo
- Unità Operativa di Radiologia, Fondazione I.R.C.C.S. Cà Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Emiliano Votta
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Paolo Zunino
- MOX, Department of Mathematics, Politecnico di Milano, Milan, Italy
| | - Alberto Redaelli
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Christian Vergara
- LaBS, Dipartimento di Chimica, Materiali e Ingegneria Chimica "Giulio Natta", Politecnico di Milano, Milan, Italy
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9
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Hebbar UU, Banerjee RK. Influence of coupled hemodynamics-arterial wall interaction on compliance in a realistic pulmonary artery with variable intravascular wall properties. Med Image Anal 2019; 57:56-71. [PMID: 31279216 DOI: 10.1016/j.media.2019.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 05/01/2019] [Accepted: 06/19/2019] [Indexed: 11/15/2022]
Abstract
Pulmonary hypertension is characterized by elevation of pulmonary artery (PA) pressure (p) and structural remodeling of the PA wall, leading to reduction in arterial compliance (c). As a step towards improving diagnosis of pulmonary disease, we use the PA branch geometry (main pulmonary artery (MPA) branching into left (LPA) and right (RPA) pulmonary arteries) obtained from MRI in conjunction with an inverse algorithm to obtain the pre-stress level in the artery walls. Next, a coupled blood-wall interaction (BWI) calculation provides hemodynamic information as well as compliance of the PA walls. We show that the computed load-free geometry from the inverse algorithm exhibits a 27.8% lower inner diameter (d) and 18.5% lower outer d compared to the in vivo geometry from MRI. Further, the mean p computed from the BWI computation in the main PA (pMPA-n) is within 4% of the mean pMPA-e (n-numerical; e-experimental). Also, the mean Q computed in the left PA (QLPA-n) is within 10% of the mean QLPA-e. Finally, the compliance cMPA-n is computed to be 27% lower than cMPA-e, while the cLPA-n is computed to be 20.4% lower than cLPA-e. Importantly, the PA shows significant intra-vascular variation in compliance, with the MPA showing higher overall compliance compared to the LPA (3.5-4 times).
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Affiliation(s)
- Ullhas U Hebbar
- 593 Rhodes Hall, Department of Mechanical Engineering, University of Cincinnati, OH, 45221, United States
| | - Rupak K Banerjee
- 593 Rhodes Hall, Department of Mechanical Engineering, University of Cincinnati, OH, 45221, United States.
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