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Bracamonte J, Truong U, Wilson J, Soares J. Correction of phase offset errors and quantification of background noise, signal-to-noise ratio, and encoded-displacement uncertainty on DENSE MRI for kinematics of the descending thoracic and abdominal aorta. Magn Reson Imaging 2024; 106:91-103. [PMID: 38092083 PMCID: PMC10842810 DOI: 10.1016/j.mri.2023.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 12/10/2023] [Indexed: 12/19/2023]
Abstract
Displacement encoding with stimulated echoes (DENSE) MRI is a phase contrast technique that allows the encoding of tissue displacement into the phase of the magnetic resonance signal. Recent developments in this technique allow the imaging of relatively thin structures such as the aortic wall. Quantifying background noise associated to DENSE MRI is required to assess the uncertainty of derived displacement measurements and for the design and implementation of adequate noise-reduction techniques. Although noise and error management of cardiac DENSE MRI has been previously studied, developments for aortic applications are scarce. Herein, we evaluate the noise and uncertainty of DENSE MRI scans at three different locations along the descending aorta: the distal aortic arch (DAA), the descending thoracic aorta (DTA), and infrarenal abdominal aorta (IAA). Additionally, we analyze three datasets from in vitro validation experiments with polyvinyl alcohol phantoms. We implement and evaluate the effectiveness of an offset-error correction algorithm and noise filtering techniques on DENSE MRI for aortic motion applications. Our results show that the phase signal of pixels composing the static background was normally distributed, centered on average at 0.003 ± 0.02 rad and - 0.02 ± 0.024 rad for each phase directions, suggesting that background noise is random, isotropic, and DENSE MRI has little offset errors. However, background signal noise significantly increased with elapsed time of the cardiac cycle; and was spatially heterogeneous consistently increased towards the anterior space. Background noise showed no significant differences between the 3 aortic locations and the in vitro experiments. However, SNR depended on the displacement of the region of interest, in consequence it was found significantly larger at DAA (16.7 ± 8.5, p = 0.003) and DTA (15.4 ± 7.6, p = 0.008) than at the IAA (8.0 ± 4.1), but not significantly different than the SNR of in vitro experiments (8.0 ± 3.7), and had an overall average of 13 ± 7. The applied methods significantly reduced the offset error and effect of noise on the estimation of encoded displacements. Finally, this analysis suggests that the implemented DENSE MRI protocol is adequate to assess the motion of healthy human aortas. However, the relative effect of noise increased considerably on the analysis of an ageing or diseased aortas with impaired mobility, calling for further analyses on pathologically stiffened aortas.
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Affiliation(s)
- Johane Bracamonte
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - Uyen Truong
- Department of Pediatrics, Division of Cardiology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - John Wilson
- Department of Biomedical Engineering and Pauley Heart Center, Virginia Commonwealth University, VA, USA
| | - Joao Soares
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, USA.
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Bracamonte JH, Saunders SK, Wilson JS, Truong UT, Soares JS. Patient-Specific Inverse Modeling of In Vivo Cardiovascular Mechanics with Medical Image-Derived Kinematics as Input Data: Concepts, Methods, and Applications. APPLIED SCIENCES-BASEL 2022; 12:3954. [PMID: 36911244 PMCID: PMC10004130 DOI: 10.3390/app12083954] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Inverse modeling approaches in cardiovascular medicine are a collection of methodologies that can provide non-invasive patient-specific estimations of tissue properties, mechanical loads, and other mechanics-based risk factors using medical imaging as inputs. Its incorporation into clinical practice has the potential to improve diagnosis and treatment planning with low associated risks and costs. These methods have become available for medical applications mainly due to the continuing development of image-based kinematic techniques, the maturity of the associated theories describing cardiovascular function, and recent progress in computer science, modeling, and simulation engineering. Inverse method applications are multidisciplinary, requiring tailored solutions to the available clinical data, pathology of interest, and available computational resources. Herein, we review biomechanical modeling and simulation principles, methods of solving inverse problems, and techniques for image-based kinematic analysis. In the final section, the major advances in inverse modeling of human cardiovascular mechanics since its early development in the early 2000s are reviewed with emphasis on method-specific descriptions, results, and conclusions. We draw selected studies on healthy and diseased hearts, aortas, and pulmonary arteries achieved through the incorporation of tissue mechanics, hemodynamics, and fluid-structure interaction methods paired with patient-specific data acquired with medical imaging in inverse modeling approaches.
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Affiliation(s)
- Johane H. Bracamonte
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA
| | - Sarah K. Saunders
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA
| | - John S. Wilson
- Department of Biomedical Engineering and Pauley Heart Center, Virginia Commonwealth University, Richmond, VA 23219, USA
| | - Uyen T. Truong
- Department of Pediatrics, School of Medicine, Children’s Hospital of Richmond at Virginia Commonwealth University, Richmond, VA 23219, USA
| | - Joao S. Soares
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA
- Correspondence:
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Fan L, Yao J, Wang L, Xu D, Tang D. Optimization of Left Ventricle Pace Maker Location Using Echo-Based Fluid-Structure Interaction Models. Front Physiol 2022; 13:843421. [PMID: 35250642 PMCID: PMC8892190 DOI: 10.3389/fphys.2022.843421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Accepted: 01/26/2022] [Indexed: 11/21/2022] Open
Abstract
INTRODUCTION Cardiac pacing has been an effective treatment in the management of patients with bradyarrhythmia and tachyarrhythmia. Different pacemaker location has different responses, and pacemaker effectiveness to each individual can also be different. A novel image-based ventricle animal modeling approach was proposed to optimize ventricular pacemaker site for better cardiac outcome. METHOD One health female adult pig (weight 42.5 kg) was used to make a pacing animal model with different ventricle pacing locations. Ventricle surface electric signal, blood pressure and echo image were acquired 15 min after the pacemaker was implanted. Echo-based left ventricle fluid-structure interaction models were constructed to perform ventricle function analysis and investigate impact of pacemaker location on cardiac outcome. With the measured electric signal map from the pig associated with the actual pacemaker site, electric potential conduction of myocardium was modeled by material stiffening and softening in our model, with stiffening simulating contraction and softening simulating relaxation. Ventricle model without pacemaker (NP model) and three ventricle models with the following pacemaker locations were simulated: right ventricular apex (RVA model), posterior interventricular septum (PIVS model) and right ventricular outflow tract (RVOT model). Since higher peak flow velocity, flow shear stress (FSS), ventricle stress and strain are linked to better cardiac function, those data were collected for model comparisons. RESULTS At the peak of filling, velocity magnitude, FSS, stress and strain for RVOT and PIVS models were 13%, 45%, 18%, 13% and 5%, 30%, 10%, 5% higher than NP model, respectively. At the peak of ejection, velocity magnitude, FSS, stress and strain for RVOT and PIVS models were 50%, 44%, 54%, 59% and 23%, 36%, 39%, 53% higher than NP model, respectively. RVA model had lower velocity, FSS, stress and strain than NP model. RVOT model had higher peak flow velocity and stress/strain than PIVS model. It indicated RVOT pacemaker site may be the best location. CONCLUSION This preliminary study indicated that RVOT model had the best performance among the four models compared. This modeling approach could be used as "virtual surgery" to try various pacemaker locations and avoid risky and dangerous surgical experiments on real patients.
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Affiliation(s)
- Longling Fan
- Faculty of Science, Kunming University of Science and Technology, Kunming, China
- School of Mathematics, Southeast University, Nanjing, China
| | - Jing Yao
- Department of Ultrasound Medicine, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Liang Wang
- School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Di Xu
- Department of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Dalin Tang
- School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
- Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA, United States
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Liu W, Cao Y, Zhou X, Han D. Interstitial Fluid Behavior and Diseases. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2100617. [PMID: 34978164 PMCID: PMC8867152 DOI: 10.1002/advs.202100617] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 10/18/2021] [Indexed: 06/14/2023]
Abstract
Living things comprise a typical hierarchical and porous medium, and their most fundamental logical architectures are interstitial structures encapsulating parenchymal structures. The recent discovery of the efficient transport mechanisms of interstitial streams has provided a new understanding of these complex activities. The substance transport of interstitial streams follows mesoscopic fluid behavior dynamics, which is intimately associated with material transfer in nanoconfined spaces and a unique signal transmission. Accordingly, the evaluation of interstitial stream transport behavior at the mesoscopic scale is essential. In this review, recent advances in physical and chemical properties, the substance transport model, and the characterization methods of interstitial streams at the mesoscopic scale, as well as the relationships between interstitial streams and disease are summarized. Interstitial stream transport can be used as a basis to fully mine hierarchal behavior in images to expand imaging behavior into an omics field. By starting from the perspective of soft matter, a new understanding can be gained of health and disease and quantitative physical markers for research, clinical diagnosis, and treatment can be provided, as well as prognosis evaluation in complex diseases such as cancer and Alzheimer's disease. This will provide a foundation for the development of medicine of soft matter.
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Affiliation(s)
- Wen‐Tao Liu
- CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing100190P. R. China
| | - Yu‐Peng Cao
- CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing100190P. R. China
- School of Future TechnologyUniversity of Chinese Academy of SciencesBeijing100049P. R. China
| | - Xiao‐Han Zhou
- CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing100190P. R. China
- School of Future TechnologyUniversity of Chinese Academy of SciencesBeijing100049P. R. China
| | - Dong Han
- CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing100190P. R. China
- School of Future TechnologyUniversity of Chinese Academy of SciencesBeijing100049P. R. China
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Yu H, Del Nido PJ, Geva T, Yang C, Wu Z, Rathod RH, Huang X, Billiar KL, Tang D. A Novel Pulmonary Valve Replacement Surgery Strategy Using Contracting Band for Patients With Repaired Tetralogy of Fallot: An MRI-Based Multipatient Modeling Study. Front Bioeng Biotechnol 2021; 9:638934. [PMID: 34095094 PMCID: PMC8170134 DOI: 10.3389/fbioe.2021.638934] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 04/08/2021] [Indexed: 11/21/2022] Open
Abstract
Patients with repaired Tetralogy of Fallot (ToF), a congenital heart defect which includes a ventricular septal defect and severe right ventricular outflow obstruction, account for the majority of cases with late-onset right ventricle (RV) failure. Current surgery procedures, including pulmonary valve replacement (PVR) with right ventricle remodeling, yield mixed results. PVR with active band insertion was hypothesized to be of clinical usage on improving RV function measured by ejection fraction (EF). In lieu of risky open-heart surgeries and experiments on animal and human, computational biomechanical models were adapted to study the impact of PVR with five band insertion options. Cardiac magnetic resonance (CMR) images were acquired from seven TOF patients before PVR surgery for model construction. For each patient, five different surgery plans combined with passive and active contraction band with contraction ratio of 20, 15, and 10% were studied. Those five plans include three single-band plans with different band locations; one plan with two bands, and one plan with three bands. Including the seven no-band models, 147 computational bi-ventricle models were constructed to simulate RV cardiac functions and identify optimal band plans. Patient variations with different band plans were investigated. Surgery plan with three active contraction bands and band active contraction ratio of 20% had the best performance on improving RV function. The mean ± SD RV ejection fraction value from the seven patients was 42.90 ± 5.68%, presenting a 4.19% absolute improvement or a 10.82% relative improvement, when compared with the baseline models (38.71 ± 5.73%, p = 0.016). The EF improvements from the seven patients varied from 2.87 to 6.01%. Surgical procedures using active contraction bands have great potential to improve RV function measured by ejection fraction for patients with repaired ToF. It is possible to have higher right ventricle ejection fraction improvement with more bands and higher band active contraction ratio. Our findings with computational models need to be further validated by animal experiments before clinical trial could become possible.
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Affiliation(s)
- Han Yu
- School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Pedro J Del Nido
- Department of Cardiac Surgery, Boston Children's Hospital, Boston, MA, United States.,Department of Surgery, Harvard Medical School, Boston, MA, United States
| | - Tal Geva
- Department of Cardiology, Boston Children's Hospital, Boston, MA, United States.,Department of Pediatrics, Harvard Medical School, Boston, MA, United States
| | - Chun Yang
- Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA, United States
| | - Zheyang Wu
- Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA, United States
| | - Rahul H Rathod
- Department of Cardiology, Boston Children's Hospital, Boston, MA, United States.,Department of Pediatrics, Harvard Medical School, Boston, MA, United States
| | - Xueying Huang
- School of Mathematical Sciences, Xiamen University, Xiamen, China
| | - Kristen L Billiar
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA, United States
| | - Dalin Tang
- School of Biological Science and Medical Engineering, Southeast University, Nanjing, China.,Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA, United States
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Yu H, Del Nido PJ, Geva T, Yang C, Wu Z, Rathod RH, Huang X, Billiar KL, Tang D. Multi-Band Surgery for Repaired Tetralogy of Fallot Patients With Reduced Right Ventricle Ejection Fraction: A Pilot Study. Front Physiol 2020; 11:198. [PMID: 32265727 PMCID: PMC7103653 DOI: 10.3389/fphys.2020.00198] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 02/20/2020] [Indexed: 12/24/2022] Open
Abstract
Introduction Right ventricle (RV) failure is one of the most common symptoms among patients with repaired tetralogy of Fallot (TOF). The current surgery treatment approach including pulmonary valve replacement (PVR) showed mixed post-surgery outcomes. A novel PVR surgical strategy using active contracting bands is proposed to improve the post-PVR outcome. In lieu of testing the risky surgical procedures on real patients, computational simulations (virtual surgery) using biomechanical ventricle models based on patient-specific cardiac magnetic resonance (CMR) data were performed to test the feasibility of the PVR procedures with active contracting bands. Different band combination and insertion options were tested to identify optimal surgery designs. Method Cardiac magnetic resonance data were obtained from one TOF patient (male, age 23) whose informed consent was obtained. A total of 21 finite element models were constructed and solved following our established procedures to investigate the outcomes of the band insertion surgery. The non-linear anisotropic Mooney–Rivlin model was used as the material model. Five different band insertion plans were simulated (three single band models with different band locations, one model with two bands, and one model with three bands). Three band contraction ratios (10, 15, and 20%) and passive bands (0% contraction ratio) were tested. RV ejection fraction was used as the measure for cardiac function. Results The RV ejection fraction from the three-band model with 20% contraction increased to 41.58% from the baseline of 37.38%, a 4.20% absolute improvement. The RV ejection fractions from the other four band models with 20% contraction rate were 39.70, 39.45, and 40.70% (two-band) and 39.17%, respectively. The mean RV stress and strain values from all of the 21 models showed only modest differences (5–11%). Conclusion This pilot study demonstrated that the three-band model with 20% band contraction ratio led to 4.20% absolute improvement in the RV ejection fraction, which is considered as clinically significant. The passive elastic bands led to the reduction of the RV ejection fractions. The modeling results and surgical strategy need to be further developed and validated by a multi-patient study and animal experiments before clinical trial could become possible. Tissue regeneration techniques are needed to produce materials for the contracting bands.
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Affiliation(s)
- Han Yu
- School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Pedro J Del Nido
- Department of Cardiac Surgery, Boston Children's Hospital, Boston, MA, United States.,Department of Surgery, Harvard Medical School, Boston, MA, United States
| | - Tal Geva
- Department of Cardiology, Boston Children's Hospital, Boston, MA, United States.,Department of Pediatrics, Harvard Medical School, Boston, MA, United States
| | - Chun Yang
- Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA, United States
| | - Zheyang Wu
- Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA, United States
| | - Rahul H Rathod
- Department of Cardiology, Boston Children's Hospital, Boston, MA, United States
| | - Xueying Huang
- School of Mathematical Sciences, Xiamen University, Xiamen, China
| | - Kristen L Billiar
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA, United States
| | - Dalin Tang
- School of Biological Science and Medical Engineering, Southeast University, Nanjing, China.,Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA, United States
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Yu H, Tang D, Geva T, Yang C, Wu Z, Rathod RH, Huang X, Billiar KL, del Nido PJ. Ventricle stress/strain comparisons between Tetralogy of Fallot patients and healthy using models with different zero-load diastole and systole morphologies. PLoS One 2019; 14:e0220328. [PMID: 31412062 PMCID: PMC6693773 DOI: 10.1371/journal.pone.0220328] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 07/12/2019] [Indexed: 12/21/2022] Open
Abstract
Patient-specific in vivo ventricle mechanical wall stress and strain conditions are important for cardiovascular investigations and should be calculated from correct zero-load ventricle morphologies. Cardiac magnetic resonance (CMR) data were obtained from 6 healthy volunteers and 12 Tetralogy of Fallot (TOF) patients with consent obtained. 3D patient-specific CMR-based ventricle models with different zero-load diastole and systole geometries due to myocardium contraction and relaxation were constructed to qualify right ventricle (RV) diastole and systole stress and strain values at begin-filling, end-filling, begin-ejection, and end-ejection, respectively. Our new models (called 2G models) can provide end-diastole and end-systole stress/strain values which models with one zero-load geometries (called 1G models) could not provide. 2G mean end-ejection stress value from the 18 participants was 321.4% higher than that from 1G models (p = 0.0002). 2G mean strain values was 230% higher than that of 1G models (p = 0.0002). TOF group (TG) end-ejection mean stress value was 105.4% higher than that of healthy group (HG) (17.54±7.42kPa vs. 8.54±0.92kPa, p = 0.0245). Worse outcome group (WG, n = 6) post pulmonary valve replacement (PVR) begin-ejection mean stress was 57.4% higher than that of better outcome group (BG, 86.94±26.29 vs. 52.93±22.86 kPa; p = 0.041). Among 7 selected parameters, End-filling stress was the best predictor to differentiate BG patients from WG patients with prediction accuracy = 0.8208 and area under receiver operating characteristic curve (AUC) value at 0.8135 (EE stress). Large scale studies are needed to further validate our findings.
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Affiliation(s)
- Han Yu
- School of Biological Science & Medical Engineering, Southeast University, Nanjing, China
| | - Dalin Tang
- School of Biological Science & Medical Engineering, Southeast University, Nanjing, China
- Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA, United States of America
| | - Tal Geva
- Department of Cardiology, Boston Children's Hospital, Department of Pediatrics, Harvard Medical School, Boston, MA, United States of America
| | - Chun Yang
- Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA, United States of America
| | - Zheyang Wu
- Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA, United States of America
| | - Rahul H. Rathod
- Department of Cardiology, Boston Children's Hospital, Department of Pediatrics, Harvard Medical School, Boston, MA, United States of America
| | - Xueying Huang
- School of Mathematical Sciences, Xiamen University, Xiamen, Fujian, China
| | - Kristen L. Billiar
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA, United States of America
| | - Pedro J. del Nido
- Department of Cardiac Surgery, Boston Children’s Hospital, Department of Surgery, Harvard Medical School, Boston, MA, United States of America
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A numerical analysis on the right and left ventricles with circular and elliptical patches. COR ET VASA 2019. [DOI: 10.33678/cor.2019.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Patient-specific in vivo right ventricle material parameter estimation for patients with tetralogy of Fallot using MRI-based models with different zero-load diastole and systole morphologies. Int J Cardiol 2018; 276:93-99. [PMID: 30217422 DOI: 10.1016/j.ijcard.2018.09.030] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 07/31/2018] [Accepted: 09/07/2018] [Indexed: 01/26/2023]
Abstract
Patient-specific in vivo ventricle material parameter determination is important for cardiovascular investigations. A new cardiac magnetic image (CMR)-based modeling approach with different zero-load diastole and systole geometries was adopted to estimate right ventricle material parameter values for healthy and patients with Tetralogy of Fallot (TOF) and seeking potential clinical applications. CMR data were obtained from 6 healthy volunteers and 16 TOF patients with consent obtained. CMR-based RV/LV models were constructed using two zero-load geometries (diastole and systole, 2G model). Material parameter values for begin-filling (BF), end-filling (EF), begin-ejection (BE), and end-ejection (EE) were recorded for analyses. Effective Young's moduli (YM) for fiber direction stress-strain curves were calculated for easy comparisons. The mean EE YM value of TOF patients was 78.6% higher than that of the healthy group (HG). The mean end-ejection YM value from worse-outcome TOF group (WG) post pulmonary valve replacement (PVR) surgery was 59.5% higher than that from the better-outcome TOF group (BG). Using begin-filling YM and end-ejection YM as predictors and the classic logistic regression model to different better-outcome group patients from worse-outcome group patients, the areas under Receiver Operating Characteristic (ROC) curves were found to be 0.797 and 0.883 for begin-filling YM and end-ejection YM, respectively. The sensitivity and specificity 0.761 and 0.755 using end-ejection YM as the predictor. This preliminary study suggests that ventricle material stiffness could be a potential parameter to be used to differentiate BG patients from WG patients with further effort and large-scale patient data validations.
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Deng L, Huang X, Yang C, Song Y, Tang D. Patient-specific CT-based 3D passive FSI model for left ventricle in hypertrophic obstructive cardiomyopathy. Comput Methods Biomech Biomed Engin 2018; 21:255-263. [PMID: 29466869 DOI: 10.1080/10255842.2018.1443215] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Left ventricular outflow tract obstruction is observed in 70% of patients with hypertrophic cardiomyopathy, which occurs in about 1 of every 500 adults in the general population. It has been widely believed that the motion of the mitral valve, in particular, its systolic anterior motion (SAM), attributes significantly to such obstruction. For a better understanding of the mitral valve motion, a 3D patient-specific fluid-structure interaction model of the left ventricle from a patient with hypertrophic obstructive cardiomyopathy based on computed tomography (CT) scan images was proposed in this study. Displacement, structural stress, pressure, flow velocity and shear stress within the left ventricle and mitral valve were extracted to characterize their behavior. The maximum shear stress on mitral valve was 9.68 [Formula: see text]. The pressure on its posterior leaflet was higher than that on the anterior leaflet and the peak pressure on the mitral valve was 93.5 mm Hg which occurred at pre-SAM time. High angles of attack (54.3 ± 22.4°) were found in this patient. The methodology established in this study may have the potential to clarify the mechanisms of SAM and ultimately optimize surgical planning by comparing the mechanical results obtained from preoperative and postoperative models.
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Affiliation(s)
- Long Deng
- a Department of Cardiac Surgery , Fuwai Hospital, Chinese Academy of Medical Sciences , Beijing , China
| | - Xueying Huang
- b Fujian Provincial Key Laboratory of Mathematical Modeling and High-Performance Scientific Computation, School of Mathematical Sciences , Xiamen University , Xiamen , China.,c Department of Mathematical Sciences , Worcester Polytechnic Institute , Worcester , MA , USA
| | - Chun Yang
- c Department of Mathematical Sciences , Worcester Polytechnic Institute , Worcester , MA , USA.,d Network Technology Research Institute, China United Network Communications Co., Ltd. , Beijing , China
| | - Yunhu Song
- a Department of Cardiac Surgery , Fuwai Hospital, Chinese Academy of Medical Sciences , Beijing , China
| | - Dalin Tang
- c Department of Mathematical Sciences , Worcester Polytechnic Institute , Worcester , MA , USA.,e School of Biological Science & Medical Engineering , Southeast University , Nanjing , China
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Fan L, Yao J, Yang C, Wu Z, Xu D, Tang D. Material stiffness parameters as potential predictors of presence of left ventricle myocardial infarction: 3D echo-based computational modeling study. Biomed Eng Online 2016; 15:34. [PMID: 27044441 PMCID: PMC4820947 DOI: 10.1186/s12938-016-0151-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 03/29/2016] [Indexed: 01/18/2023] Open
Abstract
Background Ventricle material properties are difficult to obtain under in vivo conditions and are not readily available in the current literature. It is also desirable to have an initial determination if a patient had an infarction based on echo data before more expensive examinations are recommended. A noninvasive echo-based modeling approach and a predictive method were introduced to determine left ventricle material parameters and differentiate patients with recent myocardial infarction (MI) from those without. Methods Echo data were obtained from 10 patients, 5 with MI (Infarct Group) and 5 without (Non-Infarcted Group). Echo-based patient-specific computational left ventricle (LV) models were constructed to quantify LV material properties. All patients were treated equally in the modeling process without using MI information. Systolic and diastolic material parameter values in the Mooney-Rivlin models were adjusted to match echo volume data. The equivalent Young’s modulus (YM) values were obtained for each material stress–strain curve by linear fitting for easy comparison. Predictive logistic regression analysis was used to identify the best parameters for infract prediction. Results The LV end-systole material stiffness (ES-YMf) was the best single predictor among the 12 individual parameters with an area under the receiver operating characteristic (ROC) curve of 0.9841. LV wall thickness (WT), material stiffness in fiber direction at end-systole (ES-YMf) and material stiffness variation (∆YMf) had positive correlations with LV ejection fraction with correlation coefficients r = 0.8125, 0.9495 and 0.9619, respectively. The best combination of parameters WT + ∆YMf was the best over-all predictor with an area under the ROC curve of 0.9951. Conclusion Computational modeling and material stiffness parameters may be used as a potential tool to suggest if a patient had infarction based on echo data. Large-scale clinical studies are needed to validate these preliminary findings.
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Affiliation(s)
- Longling Fan
- Department of Mathematics, Southeast University, Nanjing, 210096, China
| | - Jing Yao
- Department of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Chun Yang
- Network Technology Research Institute, China United Network Communications Co., Ltd., Beijing, 100048, China.,Mathematical Sciences Department, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA, 01609, USA
| | - Zheyang Wu
- Mathematical Sciences Department, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA, 01609, USA
| | - Di Xu
- Department of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Dalin Tang
- Department of Mathematics, Southeast University, Nanjing, 210096, China. .,Mathematical Sciences Department, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA, 01609, USA.
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Application of Elastography for the Noninvasive Assessment of Biomechanics in Engineered Biomaterials and Tissues. Ann Biomed Eng 2016; 44:705-24. [PMID: 26790865 DOI: 10.1007/s10439-015-1542-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 12/18/2015] [Indexed: 12/11/2022]
Abstract
The elastic properties of engineered biomaterials and tissues impact their post-implantation repair potential and structural integrity, and are critical to help regulate cell fate and gene expression. The measurement of properties (e.g., stiffness or shear modulus) can be attained using elastography, which exploits noninvasive imaging modalities to provide functional information of a material indicative of the regeneration state. In this review, we outline the current leading elastography methodologies available to characterize the properties of biomaterials and tissues suitable for repair and mechanobiology research. We describe methods utilizing magnetic resonance, ultrasound, and optical coherent elastography, highlighting their potential for longitudinal monitoring of implanted materials in vivo, in addition to spatiotemporal limits of each method for probing changes in cell-laden constructs. Micro-elastography methods now allow acquisitions at length scales approaching 5-100 μm in two and three dimensions. Many of the methods introduced in this review are therefore capable of longitudinal monitoring in biomaterials and tissues approaching the cellular scale. However, critical factors such as anisotropy, heterogeneity and viscoelasity-inherent in many soft tissues-are often not fully described and therefore require further advancements and future developments.
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Fan L, Yao J, Yang C, Xu D, Tang D. Modeling Active Contraction and Relaxation of Left Ventricle Using Different Zero-load Diastole and Systole Geometries for Better Material Parameter Estimation and Stress/Strain Calculations. MOLECULAR & CELLULAR BIOMECHANICS : MCB 2016; 13:33-55. [PMID: 29399004 DOI: 10.3970/mcb.2016.013.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Modeling ventricle active contraction based on in vivo data is extremely challenging because of complex ventricle geometry, dynamic heart motion and active contraction where the reference geometry (zero-stress geometry) changes constantly. A new modeling approach using different diastole and systole zero-load geometries was introduced to handle the changing zero-load geometries for more accurate stress/strain calculations. Echo image data were acquired from 5 patients with infarction (Infarct Group) and 10 without (Non-Infarcted Group). Echo-based computational two-layer left ventricle models using one zero-load geometry (1G) and two zero-load geometries (2G) were constructed. Material parameter values in Mooney-Rivlin models were adjusted to match echo volume data. Effective Young's moduli (YM) were calculated for easy comparison. For diastole phase, begin-filling (BF) mean YM value in the fiber direction (YMf) was 738% higher than its end-diastole (ED) value (645.39 kPa vs. 76.97 kPa, p=3.38E-06). For systole phase, end-systole (ES) YMf was 903% higher than its begin-ejection (BE) value (1025.10 kPa vs. 102.11 kPa, p=6.10E-05). Comparing systolic and diastolic material properties, ES YMf was 59% higher than its BF value (1025.10 kPa vs. 645.39 kPa. p=0.0002). BE mean stress value was 514% higher than its ED value (299.69 kPa vs. 48.81 kPa, p=3.39E-06), while BE mean strain value was 31.5% higher than its ED value (0.9417 vs. 0.7162, p=0.004). Similarly, ES mean stress value was 562% higher than its BF value (19.74 kPa vs. 2.98 kPa, p=6.22E-05), and ES mean strain value was 264% higher than its BF value (0.1985 vs. 0.0546, p=3.42E-06). 2G models improved over 1G model limitations and may provide better material parameter estimation and stress/strain calculations.
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Affiliation(s)
- Longling Fan
- Department of Mathematics, Southeast University, Nanjing, 210096, China
| | - Jing Yao
- Department of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Chun Yang
- Network Technology Research Institute, China United Network Communications Co., Ltd., Beijing, 100048, China
| | - Di Xu
- Department of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Dalin Tang
- Department of Mathematics, Southeast University, Nanjing, 210096, China.,Mathematical Sciences Department, Worcester Polytechnic Institute, MA 01609 USA
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Fan L, Yao J, Yang C, Tang D, Xu D. Infarcted Left Ventricles Have Stiffer Material Properties and Lower Stiffness Variation: Three-Dimensional Echo-Based Modeling to Quantify In Vivo Ventricle Material Properties. J Biomech Eng 2015; 137:081005. [PMID: 25994130 DOI: 10.1115/1.4030668] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Indexed: 11/08/2022]
Abstract
Methods to quantify ventricle material properties noninvasively using in vivo data are of great important in clinical applications. An ultrasound echo-based computational modeling approach was proposed to quantify left ventricle (LV) material properties, curvature, and stress/strain conditions and find differences between normal LV and LV with infarct. Echo image data were acquired from five patients with myocardial infarction (I-Group) and five healthy volunteers as control (H-Group). Finite element models were constructed to obtain ventricle stress and strain conditions. Material stiffening and softening were used to model ventricle active contraction and relaxation. Systolic and diastolic material parameter values were obtained by adjusting the models to match echo volume data. Young's modulus (YM) value was obtained for each material stress-strain curve for easy comparison. LV wall thickness, circumferential and longitudinal curvatures (C- and L-curvature), material parameter values, and stress/strain values were recorded for analysis. Using the mean value of H-Group as the base value, at end-diastole, I-Group mean YM value for the fiber direction stress-strain curve was 54% stiffer than that of H-Group (136.24 kPa versus 88.68 kPa). At end-systole, the mean YM values from the two groups were similar (175.84 kPa versus 200.2 kPa). More interestingly, H-Group end-systole mean YM was 126% higher that its end-diastole value, while I-Group end-systole mean YM was only 29% higher that its end-diastole value. This indicated that H-Group had much greater systole-diastole material stiffness variations. At beginning-of-ejection (BE), LV ejection fraction (LVEF) showed positive correlation with C-curvature, stress, and strain, and negative correlation with LV volume, respectively. At beginning-of-filling (BF), LVEF showed positive correlation with C-curvature and strain, but negative correlation with stress and LV volume, respectively. Using averaged values of two groups at BE, I-Group stress, strain, and wall thickness were 32%, 29%, and 18% lower (thinner), respectively, compared to those of H-Group. L-curvature from I-Group was 61% higher than that from H-Group. Difference in C-curvature between the two groups was not statistically significant. Our results indicated that our modeling approach has the potential to determine in vivo ventricle material properties, which in turn could lead to methods to infer presence of infarct from LV contractibility and material stiffness variations. Quantitative differences in LV volume, curvatures, stress, strain, and wall thickness between the two groups were provided.
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15
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Jiang C, Liu GR, Han X, Zhang ZQ, Zeng W. A smoothed finite element method for analysis of anisotropic large deformation of passive rabbit ventricles in diastole. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2015; 31:e02697. [PMID: 25382158 DOI: 10.1002/cnm.2697] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 10/29/2014] [Accepted: 10/30/2014] [Indexed: 06/04/2023]
Abstract
The smoothed FEM (S-FEM) is firstly extended to explore the behavior of 3D anisotropic large deformation of rabbit ventricles during the passive filling process in diastole. Because of the incompressibility of myocardium, a special method called selective face-based/node-based S-FEM using four-node tetrahedral elements (FS/NS-FEM-TET4) is adopted in order to avoid volumetric locking. To validate the proposed algorithms of FS/NS-FEM-TET4, the 3D Lame problem is implemented. The performance contest results show that our FS/NS-FEM-TET4 is accurate, volumetric locking-free and insensitive to mesh distortion than standard linear FEM because of absence of isoparametric mapping. Actually, the efficiency of FS/NS-FEM-TET4 is comparable with higher-order FEM, such as 10-node tetrahedral elements. The proposed method for Holzapfel myocardium hyperelastic strain energy is also validated by simple shear tests through the comparison outcomes reported in available references. Finally, the FS/NS-FEM-TET4 is applied in the example of the passive filling of MRI-based rabbit ventricles with fiber architecture derived from rule-based algorithm to demonstrate its efficiency. Hence, we conclude that FS/NS-FEM-TET4 is a promising alternative other than FEM in passive cardiac mechanics.
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Affiliation(s)
- Chen Jiang
- State Key Laboratory of Advanced Technology of Design and Manufacturing for Vehicle Body, Hunan University, 410082, People's Republic of China
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Forouzan O, Flink E, Warczytowa J, Thate N, Hanske A, Lee T, Roldan-Alzate A, François C, Wieben O, Chesler NC. Low Cost Magnetic Resonance Imaging-Compatible Stepper Exercise Device for Use in Cardiac Stress Tests. J Med Device 2014; 8:0450021-450028. [PMID: 25699131 DOI: 10.1115/1.4027343] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 03/26/2014] [Indexed: 12/13/2022] Open
Abstract
Cardiovascular disease is the leading cause of death worldwide. Many cardiovascular diseases are better diagnosed during a cardiac stress test. Current approaches include either exercise or pharmacological stress echocardiography and pharmacological stress magnetic resonance imaging (MRI). MRI is the most accurate noninvasive method of assessing cardiac function. Currently there are very few exercise devices that allow collection of cardiovascular MRI data during exercise. We developed a low-cost exercise device that utilizes adjustable weight resistance and is compatible with magnetic resonance (MR) imaging. It is equipped with electronics that measure power output. Our device allows subjects to exercise with a leg-stepping motion while their torso is in the MR imager. The device is easy to mount on the MRI table and can be adjusted for different body sizes. Pilot tests were conducted with 5 healthy subjects (3 male and 2 female, 29.2 ± 3.9 yr old) showing significant exercise-induced changes in heart rate (+42%), cardiac output (+40%) and mean pulmonary artery (PA) flow (+%49) post exercise. These data demonstrate that our MR compatible stepper exercise device successfully generated a hemodynamically stressed state while allowing for high quality imaging. The adjustable weight resistance allows exercise stress testing of subjects with variable exercise capacities. This low-cost device has the potential to be used in a variety of pathologies that require a cardiac stress test for diagnosis and assessment of disease progression.
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Affiliation(s)
- Omid Forouzan
- Department of Biomedical Engineering, University of Wisconsin-Madison , Engineering Centers Building, 1550 Engineering Drive, Madison, WI 53706 e-mail:
| | - Evan Flink
- Department of Biomedical Engineering, University of Wisconsin-Madison , Engineering Centers Building, 1550 Engineering Drive, Madison, WI 53706 e-mail:
| | - Jared Warczytowa
- Department of Biomedical Engineering, University of Wisconsin-Madison , Engineering Centers Building, 1550 Engineering Drive, Madison, WI 53706 e-mail:
| | - Nick Thate
- Department of Biomedical Engineering, University of Wisconsin-Madison , Engineering Centers Building, 1550 Engineering Drive, Madison, WI 53706 e-mail:
| | - Andrew Hanske
- Department of Biomedical Engineering, University of Wisconsin-Madison , Engineering Centers Building, 1550 Engineering Drive, Madison, WI 53706 e-mail:
| | - Tongkeun Lee
- Department of Biomedical Engineering, University of Wisconsin-Madison , Engineering Centers Building, 1550 Engineering Drive, Madison, WI 53706 e-mail:
| | - Alejandro Roldan-Alzate
- Department of Medical Physics, Wisconsin Institutes for Medical Research , 1111 Highland Avenue, Madison, WI 53705-2275
| | - Chris François
- Department of Radiology, University of Wisconsin , School of Medicine and Public Health, E3/366 Clinical Science Center, 600 Highland Avenue, Madison, WI 53792-3252 e-mail:
| | - Oliver Wieben
- Department of Biomedical Engineering, University of Wisconsin-Madison , Engineering Centers Building, 1550 Engineering Drive, Madison, WI 53706
| | - Naomi C Chesler
- Department of Biomedical Engineering, University of Wisconsin-Madison , Engineering Centers Building, 1550 Engineering Drive, Madison, WI 53706 e-mail:
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Zhang Z, Ashraf M, Sahn DJ, Song X. Temporally diffeomorphic cardiac motion estimation from three-dimensional echocardiography by minimization of intensity consistency error. Med Phys 2014; 41:052902. [PMID: 24784402 PMCID: PMC4000394 DOI: 10.1118/1.4867864] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Revised: 02/14/2014] [Accepted: 02/22/2014] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Quantitative analysis of cardiac motion is important for evaluation of heart function. Three dimensional (3D) echocardiography is among the most frequently used imaging modalities for motion estimation because it is convenient, real-time, low-cost, and nonionizing. However, motion estimation from 3D echocardiographic sequences is still a challenging problem due to low image quality and image corruption by noise and artifacts. METHODS The authors have developed a temporally diffeomorphic motion estimation approach in which the velocity field instead of the displacement field was optimized. The optimal velocity field optimizes a novel similarity function, which we call the intensity consistency error, defined as multiple consecutive frames evolving to each time point. The optimization problem is solved by using the steepest descent method. RESULTS Experiments with simulated datasets, images of anex vivo rabbit phantom, images of in vivo open-chest pig hearts, and healthy human images were used to validate the authors' method. Simulated and real cardiac sequences tests showed that results in the authors' method are more accurate than other competing temporal diffeomorphic methods. Tests with sonomicrometry showed that the tracked crystal positions have good agreement with ground truth and the authors' method has higher accuracy than the temporal diffeomorphic free-form deformation (TDFFD) method. Validation with an open-access human cardiac dataset showed that the authors' method has smaller feature tracking errors than both TDFFD and frame-to-frame methods. CONCLUSIONS The authors proposed a diffeomorphic motion estimation method with temporal smoothness by constraining the velocity field to have maximum local intensity consistency within multiple consecutive frames. The estimated motion using the authors' method has good temporal consistency and is more accurate than other temporally diffeomorphic motion estimation methods.
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Affiliation(s)
- Zhijun Zhang
- Department of Biomedical Engineering, Oregon Health and Science University (OHSU), 3181 Southwest Sam Jackson Park Road, Portland, Oregon 97239
| | - Muhammad Ashraf
- Department of Pediatric Cardiology, Oregon Health and Science University, 3181 Southwest Sam Jackson Park Road, Portland, Oregon 97239
| | - David J Sahn
- Department of Biomedical Engineering, Oregon Health and Science University (OHSU), 3181 Southwest Sam Jackson Park Road, Portland, Oregon 97239 and Department of Pediatric Cardiology, Oregon Health and Science University, 3181 Southwest Sam Jackson Park Road, Portland, Oregon 97239
| | - Xubo Song
- Department of Biomedical Engineering, Oregon Health and Science University (OHSU), 3181 Southwest Sam Jackson Park Road, Portland, Oregon 97239
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Woo J, Stone M, Suo Y, Murano EZ, Prince JL. Tissue-point motion tracking in the tongue from cine MRI and tagged MRI. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2014; 57:S626-S636. [PMID: 24686470 PMCID: PMC4465136 DOI: 10.1044/2014_jslhr-s-12-0208] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
PURPOSE Accurate tissue motion tracking within the tongue can help professionals diagnose and treat vocal tract-related disorders, evaluate speech quality before and after surgery, and conduct various scientific studies. The authors compared tissue tracking results from 4 widely used deformable registration (DR) methods applied to cine magnetic resonance imaging (MRI) with harmonic phase (HARP)-based tracking applied to tagged MRI. METHOD Ten subjects repeated the phrase "a geese" multiple times while sagittal images of the head were collected at 26 Hz, first in a tagged MRI data set and then in a cine MRI data set. HARP tracked the motion of 8 specified tissue points in the tagged data set. Four DR methods including diffeomorphic demons and free-form deformations based on cubic B-spline with 3 different similarity measures were used to track the same 8 points in the cine MRI data set. Individual points were tracked and length changes of several muscles were calculated using the DR- and HARP-based tracking methods. RESULTS The results showed that the DR tracking errors were nonsystematic and varied in direction, amount, and timing across speakers and within speakers. Comparison of HARP and DR tracking with manual tracking showed better tracking results for HARP except at the tongue surface, where mistracking caused greater errors in HARP than DR. CONCLUSIONS Tissue point tracking using DR tracking methods contains nonsystematic tracking errors within and across subjects, making it less successful than tagged MRI tracking within the tongue. However, HARP sometimes mistracks points at the tongue surface of tagged MRI because of its limited bandpass filter and tag pattern fading, so that DR has better success measuring surface tissue points on cine MRI than HARP does. Therefore, a hybrid method is being explored.
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Pop M, Ghugre NR, Ramanan V, Morikawa L, Stanisz G, Dick AJ, Wright GA. Quantification of fibrosis in infarcted swine hearts byex vivolate gadolinium-enhancement and diffusion-weighted MRI methods. Phys Med Biol 2013; 58:5009-28. [DOI: 10.1088/0031-9155/58/15/5009] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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20
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Tang D, Yang C, Geva T, Rathod R, Yamauchi H, Gooty V, Tang A, Kural MH, Billiar KL, Gaudette G, del Nido PJ. A Multiphysics Modeling Approach to Develop Right Ventricle Pulmonary Valve Replacement Surgical Procedures with a Contracting Band to Improve Ventricle Ejection Fraction. COMPUTERS & STRUCTURES 2013; 122:78-87. [PMID: 23667272 PMCID: PMC3649854 DOI: 10.1016/j.compstruc.2012.11.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Patients with repaired tetralogy of Fallot account for the majority of cases with late onset right ventricle (RV) failure. A new surgical procedure placing an elastic band in the right ventricle is proposed to improve RV function measured by ejection fraction. A multiphysics modeling approach is developed to combine cardiac magnetic resonance imaging, modeling, tissue engineering and mechanical testing to demonstrate feasibility of the new surgical procedure. Our modeling results indicated that the new surgical procedure has the potential to improve right ventricle ejection fraction by 2-7% which compared favorably with recently published drug trials to treat LV heart failure.
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Affiliation(s)
- Dalin Tang
- Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA 01609
| | - Chun Yang
- Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA 01609
- School of Mathematical Sciences, Beijing Normal University, Key Laboratory of Mathematics and Complex Systems, Ministry of Education, Beijing, 100875, China
| | - Tal Geva
- Dept of Cardiology, Children’s Hospital Boston, Dept of Pediatrics, Harvard Medical School, Boston, MA 02115 USA
| | - Rahul Rathod
- Dept of Cardiology, Children’s Hospital Boston, Dept of Pediatrics, Harvard Medical School, Boston, MA 02115 USA
| | - Haruo Yamauchi
- Dept. of Cardiac Surgery, Children’s Hospital Boston, Dept of Surgery, Harvard Medical School, Boston, MA 02115 USA
| | - Vasu Gooty
- Dept of Cardiology, Children’s Hospital Boston, Dept of Pediatrics, Harvard Medical School, Boston, MA 02115 USA
| | - Alexander Tang
- Dept of Cardiology, Children’s Hospital Boston, Dept of Pediatrics, Harvard Medical School, Boston, MA 02115 USA
| | - Mehmet H. Kural
- Dept of Biomedical Engineering, Worcester Polytechnic Institute, MA 01609, USA
| | - Kristen L. Billiar
- Dept of Biomedical Engineering, Worcester Polytechnic Institute, MA 01609, USA
- Department of Surgery, University of Massachusetts Medical School, Worcester, MA 01655
| | - Glenn Gaudette
- Dept of Biomedical Engineering, Worcester Polytechnic Institute, MA 01609, USA
| | - Pedro J. del Nido
- Dept. of Cardiac Surgery, Children’s Hospital Boston, Dept of Surgery, Harvard Medical School, Boston, MA 02115 USA
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Zhang Z, Friedman D, Dione DP, Lin BA, Duncan JS, Sinusas AJ, Sampath S. Assessment of left ventricular 2D flow pathlines during early diastole using spatial modulation of magnetization with polarity alternating velocity encoding: a study in normal volunteers and canine animals with myocardial infarction. Magn Reson Med 2012; 70:766-75. [PMID: 23044637 DOI: 10.1002/mrm.24517] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 08/23/2012] [Accepted: 09/12/2012] [Indexed: 11/10/2022]
Abstract
A high-temporal resolution 2D flow pathline analysis method to study early diastolic filling is presented. Filling patterns in normal volunteers (n = 8) and canine animals [baseline (n = 1) and infarcted (n = 6)] are studied. Data are acquired using spatial modulation of magnetization with polarity alternating velocity encoding, which permits simultaneous quantification of 1D blood velocities (using phase contrast encoding) and myocardial strain (using spatial modulation of magnetization tagging and harmonic phase analysis) at high-temporal resolution of 14 ms within a single breath hold. Virtual emitter particles, released from the mitral valve plane every time frame during rapid filling, are tracked to depict the 2D pathlines on the imaged plane. The pathline regional distribution is compared with myocardial longitudinal strains and to regional pressure gradients. Quantitative analysis of net kinetic energy of pathlines is finally performed. Our results demonstrate a linear correlation (r(2) = 0.85) between pathline spatial distribution and myocardial strain. Peak net kinetic energy of 0.06 ± 0.01 mJ in normal volunteers, 0.043 mJ in baseline dog, 0.143 ± 0.03 mJ in infarcted dogs with nominal flow dysfunction, and 0.016 ± 0.007 mJ in infarcted dogs with severe flow dysfunction is observed. In conclusion, 2D pathline analysis provides a direct regional assessment of early diastolic filling patterns and is sensitive to abnormalities in early diastolic filling.
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Affiliation(s)
- Ziheng Zhang
- Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut, USA
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Glaser KJ, Manduca A, Ehman RL. Review of MR elastography applications and recent developments. J Magn Reson Imaging 2012; 36:757-74. [PMID: 22987755 PMCID: PMC3462370 DOI: 10.1002/jmri.23597] [Citation(s) in RCA: 160] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The technique of MR elastography (MRE) has emerged as a useful modality for quantitatively imaging the mechanical properties of soft tissues in vivo. Recently, MRE has been introduced as a clinical tool for evaluating chronic liver disease, but many other potential applications are being explored. These applications include measuring tissue changes associated with diseases of the liver, breast, brain, heart, and skeletal muscle including both focal lesions (e.g., hepatic, breast, and brain tumors) and diffuse diseases (e.g., fibrosis and multiple sclerosis). The purpose of this review article is to summarize some of the recent developments of MRE and to highlight some emerging applications.
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Affiliation(s)
| | - Armando Manduca
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
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Hirsch S, Posnansky O, Papazoglou S, Elgeti T, Braun J, Sack I. Measurement of vibration-induced volumetric strain in the human lung. Magn Reson Med 2012; 69:667-74. [PMID: 22529038 DOI: 10.1002/mrm.24294] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 03/08/2012] [Accepted: 03/21/2012] [Indexed: 01/22/2023]
Abstract
Noninvasive image-based measurement of intrinsic tissue pressure is of great interest in the diagnosis and characterization of diseases. Therefore, we propose to exploit the capability of phase-contrast MRI to measure three-dimensional vector fields of tissue motion for deriving volumetric strain induced by external vibration. Volumetric strain as given by the divergence of mechanical displacement fields is related to tissue compressibility and is thus sensitive to the state of tissue pressure. This principle is demonstrated by the measurement of three-dimensional vector fields of 50-Hz oscillations in a compressible agarose phantom and in the lungs of nine healthy volunteers. In the phantom, the magnitude of the oscillating divergence increased by about 400% with 4.8 bar excess air pressure, corresponding to an effective-medium compression modulus of 230 MPa. In lungs, the averaged divergence magnitude increased in all volunteers (N = 9) between 7 and 78% from expiration to inspiration. Measuring volumetric strain by MRI provides a compression-sensitive parameter of tissue mechanics, which varies with the respiratory state in the lungs. In future clinical applications for diagnosis and characterization of lung emphysema, fibrosis, or cancer, divergence-sensitive MRI may serve as a noninvasive marker sensitive to disease-related alterations of regional elastic recoil pressure in the lungs.
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Affiliation(s)
- Sebastian Hirsch
- Department of Radiology, Charité-Universitätsmedizin Berlin, Campus Charité Mitte, Berlin, Germany
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24
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Yang C, Tang D, Geva T, Rathod R, Yamauchi H, Gooty V, Tang A, Gaudette G, Billiar KL, Kural MH, del Nido PJ. Using contracting band to improve right ventricle ejection fraction for patients with repaired tetralogy of Fallot: a modeling study using patient-specific CMR-based 2-layer anisotropic models of human right and left ventricles. J Thorac Cardiovasc Surg 2012; 145:285-93, 293.e1-2. [PMID: 22487437 DOI: 10.1016/j.jtcvs.2012.03.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Revised: 02/09/2012] [Accepted: 03/12/2012] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Patients with repaired tetralogy of Fallot account for most cases of late-onset right ventricle failure. The current surgical approach, which includes pulmonary valve replacement/insertion, has yielded mixed results. A new surgical option of placing an elastic band in the right ventricle is proposed to improve right ventricular cardiac function as measured by the ejection fraction. METHODS A total of 20 computational right ventricular/left ventricular/patch/band combination models using cardiac magnetic resonance imaging from a patient with tetralogy of Fallot were constructed to investigate the effect of band material stiffness variations, band length, and active contraction. These models included 4 different band material properties, 3 band length, 3 active contracting band materials, and models with patch and scar replaced by contracting tissue. RESULTS Our results indicated that the band insertion, combined with active band contraction and tissue regeneration techniques that restore right ventricular myocardium, has the potential to improve right ventricular ejection fraction by 7.5% (41.63% ejection fraction from the best active band model to more than 34.10% ejection fraction from baseline passive band model) and 4.2% (41.63% from the best active band model compared with cardiac magnetic resonance imaging-measured ejection fraction of 37.45%). CONCLUSIONS The cardiac magnetic resonance imaging-based right ventricular/left ventricular/patch/band model provides a proof of concept for using elastic bands to improve right ventricular cardiac function. Band insertion, combined with myocardium regeneration techniques and right ventricular remodeling surgical procedures, has the potential to improve ventricular function in patients with repaired tetralogy of Fallot and other similar forms of right ventricular dysfunction after surgery. Additional investigations using in vitro experiments, animal models, and, finally, patient studies are warranted.
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Affiliation(s)
- Chun Yang
- Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, Mass 01609, USA
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Zhang Z, Dione DP, Brown PB, Shapiro EM, Sinusas AJ, Sampath S. Assessment of early diastolic strain-velocity temporal relationships using spatial modulation of magnetization with polarity alternating velocity encoding (SPAMM-PAV). Magn Reson Med 2011; 66:1627-38. [PMID: 21630348 PMCID: PMC3166543 DOI: 10.1002/mrm.22965] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 02/22/2011] [Accepted: 03/18/2011] [Indexed: 01/08/2023]
Abstract
A novel MR imaging technique, spatial modulation of magnetization with polarity alternating velocity encoding (SPAMM-PAV), is presented to simultaneously examine the left ventricular early diastolic temporal relationships between myocardial deformation and intra-cavity hemodynamics with a high temporal resolution of 14 ms. This approach is initially evaluated in a dynamic flow and tissue mimicking phantom. A comparison of regional longitudinal strains and intra-cavity pressure differences (integration of computed in-plane pressure gradients within a selected region) in relation to mitral valve inflow velocities is performed in eight normal volunteers. Our results demonstrate that apical regions have higher strain rates (0.145 ± 0.005 %/ms) during the acceleration period of rapid filling compared to mid-ventricular (0.114 ± 0.007 %/ms) and basal regions (0.088 ± 0.009 %/ms), and apical strain curves plateau at peak mitral inflow velocity. This pattern is reversed during the deceleration period, when the strain-rates in the basal regions are the highest (0.027 ± 0.003 %/ms) due to ongoing basal stretching. A positive base-to-apex gradient in peak pressure difference is observed during acceleration, followed by a negative base-to-apex gradient during deceleration. These studies shed insight into the regional volumetric and pressure difference changes in the left ventricle during early diastolic filling.
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Affiliation(s)
- Ziheng Zhang
- Department of Diagnostic Radiology, Yale University School of Medicine, PO Box 208043, TAC N153, New Haven, CT 06520-8043, USA
| | - Donald P. Dione
- Section of Cardiovascular Medicine, Yale University School of Medicine, PO Box 208043, TAC N153, New Haven, CT 06520-8043, USA
| | - Peter B. Brown
- Department of Diagnostic Radiology, Yale University School of Medicine, PO Box 208043, TAC N153, New Haven, CT 06520-8043, USA
| | - Erik M. Shapiro
- Department of Diagnostic Radiology, Yale University School of Medicine, PO Box 208043, TAC N153, New Haven, CT 06520-8043, USA
| | - Albert J. Sinusas
- Department of Diagnostic Radiology, Yale University School of Medicine, PO Box 208043, TAC N153, New Haven, CT 06520-8043, USA
- Section of Cardiovascular Medicine, Yale University School of Medicine, PO Box 208043, TAC N153, New Haven, CT 06520-8043, USA
| | - Smita Sampath
- Department of Diagnostic Radiology, Yale University School of Medicine, PO Box 208043, TAC N153, New Haven, CT 06520-8043, USA
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Ibrahim ESH. Myocardial tagging by cardiovascular magnetic resonance: evolution of techniques--pulse sequences, analysis algorithms, and applications. J Cardiovasc Magn Reson 2011; 13:36. [PMID: 21798021 PMCID: PMC3166900 DOI: 10.1186/1532-429x-13-36] [Citation(s) in RCA: 203] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 07/28/2011] [Indexed: 02/06/2023] Open
Abstract
Cardiovascular magnetic resonance (CMR) tagging has been established as an essential technique for measuring regional myocardial function. It allows quantification of local intramyocardial motion measures, e.g. strain and strain rate. The invention of CMR tagging came in the late eighties, where the technique allowed for the first time for visualizing transmural myocardial movement without having to implant physical markers. This new idea opened the door for a series of developments and improvements that continue up to the present time. Different tagging techniques are currently available that are more extensive, improved, and sophisticated than they were twenty years ago. Each of these techniques has different versions for improved resolution, signal-to-noise ratio (SNR), scan time, anatomical coverage, three-dimensional capability, and image quality. The tagging techniques covered in this article can be broadly divided into two main categories: 1) Basic techniques, which include magnetization saturation, spatial modulation of magnetization (SPAMM), delay alternating with nutations for tailored excitation (DANTE), and complementary SPAMM (CSPAMM); and 2) Advanced techniques, which include harmonic phase (HARP), displacement encoding with stimulated echoes (DENSE), and strain encoding (SENC). Although most of these techniques were developed by separate groups and evolved from different backgrounds, they are in fact closely related to each other, and they can be interpreted from more than one perspective. Some of these techniques even followed parallel paths of developments, as illustrated in the article. As each technique has its own advantages, some efforts have been made to combine different techniques together for improved image quality or composite information acquisition. In this review, different developments in pulse sequences and related image processing techniques are described along with the necessities that led to their invention, which makes this article easy to read and the covered techniques easy to follow. Major studies that applied CMR tagging for studying myocardial mechanics are also summarized. Finally, the current article includes a plethora of ideas and techniques with over 300 references that motivate the reader to think about the future of CMR tagging.
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Tang D, Yang C, Geva T, Gaudette G, del Nido PJ. Multi-Physics MRI-Based Two-Layer Fluid-Structure Interaction Anisotropic Models of Human Right and Left Ventricles with Different Patch Materials: Cardiac Function Assessment and Mechanical Stress Analysis. COMPUTERS & STRUCTURES 2011; 89:1059-1068. [PMID: 21765559 PMCID: PMC3134331 DOI: 10.1016/j.compstruc.2010.12.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Multi-physics right and left ventricle (RV/LV) fluid-structure interaction (FSI) models were introduced to perform mechanical stress analysis and evaluate the effect of patch materials on RV function. The FSI models included three different patch materials (Dacron scaffold, treated pericardium, and contracting myocardium), two-layer construction, fiber orientation, and active anisotropic material properties. The models were constructed based on cardiac magnetic resonance (CMR) images acquired from a patient with severe RV dilatation and solved by ADINA. Our results indicate that the patch model with contracting myocardium leads to decreased stress level in the patch area, improved RV function and patch area contractility.
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Affiliation(s)
- Dalin Tang
- Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA 01609
| | - Chun Yang
- Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA 01609
- School of Mathematics, Beijing Normal University, Beijing, China
| | - Tal Geva
- Dept of Cardiology, Children’s Hospital Boston, Dept of Pediatrics, Harvard Medical School, Boston, MA 02115 USA
| | - Glenn Gaudette
- Dept of Biomedical Engineering, Worcester Polytechnic Institute, MA 01609, USA
| | - Pedro J. del Nido
- Dept. of Cardiac Surgery, Children’s Hospital Boston, Dept of Surgery, Harvard Medical School, Boston, MA 02115 USA
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Tang D, Yang C, Geva T, del Nido PJ. Image-Based Patient-Specific Ventricle Models with Fluid-Structure Interaction for Cardiac Function Assessment and Surgical Design Optimization. PROGRESS IN PEDIATRIC CARDIOLOGY 2010; 30:51-62. [PMID: 21344066 PMCID: PMC3041970 DOI: 10.1016/j.ppedcard.2010.09.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recent advances in medical imaging technology and computational modeling techniques are making it possible that patient-specific computational ventricle models be constructed and used to test surgical hypotheses and replace empirical and often risky clinical experimentation to examine the efficiency and suitability of various reconstructive procedures in diseased hearts. In this paper, we provide a brief review on recent development in ventricle modeling and its potential application in surgical planning and management of tetralogy of Fallot (ToF) patients. Aspects of data acquisition, model selection and construction, tissue material properties, ventricle layer structure and tissue fiber orientations, pressure condition, model validation and virtual surgery procedures (changing patient-specific ventricle data and perform computer simulation) were reviewed. Results from a case study using patient-specific cardiac magnetic resonance (CMR) imaging and right/left ventricle and patch (RV/LV/Patch) combination model with fluid-structure interactions (FSI) were reported. The models were used to evaluate and optimize human pulmonary valve replacement/insertion (PVR) surgical procedure and patch design and test a surgical hypothesis that PVR with small patch and aggressive scar tissue trimming in PVR surgery may lead to improved recovery of RV function and reduced stress/strain conditions in the patch area.
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Affiliation(s)
- Dalin Tang
- Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA 01609
| | - Chun Yang
- Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA 01609
- School of Mathematics, Beijing Normal University, Beijing, China
| | - Tal Geva
- Dept of Cardiology, Children's Hospital Boston, Dept of Pediatrics, Harvard Medical School, Boston, MA 02115 USA
| | - Pedro J. del Nido
- Dept. of Cardiac Surgery, Children’s Hospital Boston, Dept of Surgery, Harvard Medical School, Boston, MA 02115 USA
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Bazilevs Y, del Alamo JC, Humphrey JD. From imaging to prediction: Emerging non-invasive methods in pediatric cardiology. PROGRESS IN PEDIATRIC CARDIOLOGY 2010. [DOI: 10.1016/j.ppedcard.2010.09.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Elgeti T, Laule M, Kaufels N, Schnorr J, Hamm B, Samani A, Braun J, Sack I. Cardiac MR elastography: comparison with left ventricular pressure measurement. J Cardiovasc Magn Reson 2009; 11:44. [PMID: 19900266 PMCID: PMC2777142 DOI: 10.1186/1532-429x-11-44] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Accepted: 11/09/2009] [Indexed: 01/11/2023] Open
Abstract
PURPOSE OF STUDY To compare magnetic resonance elastography (MRE) with ventricular pressure changes in an animal model. METHODS Three pigs of different cardiac physiology (weight, 25 to 53 kg; heart rate, 61 to 93 bpm; left ventricular [LV] end-diastolic volume, 35 to 70 ml) were subjected to invasive LV pressure measurement by catheter and noninvasive cardiac MRE. Cardiac MRE was performed in a short-axis view of the heart and applying a 48.3-Hz shear-wave stimulus. Relative changes in LV-shear wave amplitudes during the cardiac cycle were analyzed. Correlation coefficients between wave amplitudes and LV pressure as well as between wave amplitudes and LV diameter were determined. RESULTS A relationship between MRE and LV pressure was observed in all three animals (R2 >or= 0.76). No correlation was observed between MRE and LV diameter (R2 CONCLUSION Externally induced shear waves provide information reflecting intraventricular pressure changes which, if substantiated in further experiments, has potential to make cardiac MRE a unique noninvasive imaging modality for measuring pressure-volume function of the heart.
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Affiliation(s)
- Thomas Elgeti
- Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Mitte, Charitéplatz 1, 10117 Berlin, Germany
| | - Michael Laule
- Department of Medicine (Cardiology, Angiology, Pulmonology) Charité - Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany
| | - Nikola Kaufels
- Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Mitte, Charitéplatz 1, 10117 Berlin, Germany
| | - Jörg Schnorr
- Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Mitte, Charitéplatz 1, 10117 Berlin, Germany
| | - Bernd Hamm
- Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Mitte, Charitéplatz 1, 10117 Berlin, Germany
| | - Abbas Samani
- Department of Medical Biophysics, University of Western Ontario, Ontario, Canada
- Department of Electrical and Computer Engineering, University of Western Ontario, Ontario, Canada
| | - Jürgen Braun
- Institute of Medical Informatics, Charité - Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12200 Berlin, Germany
| | - Ingolf Sack
- Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Mitte, Charitéplatz 1, 10117 Berlin, Germany
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Del Alamo JC, Marsden AL, Lasheras JC. Recent advances in the application of computational mechanics to the diagnosis and treatment of cardiovascular disease. Rev Esp Cardiol 2009; 62:781-805. [PMID: 19709514 PMCID: PMC6089365 DOI: 10.1016/s1885-5857(09)72359-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
During the last 30 years, research into the pathogenesis and progression of cardiovascular disease has had to employ a multidisciplinary approach involving a wide range of subject areas, from molecular and cell biology to computational mechanics and experimental solid and fluid mechanics. In general, research was driven by the need to provide answers to questions of critical importance for disease management. Ongoing improvements in the spatial resolution of medical imaging equipment coupled to an exponential growth in the capacity, flexibility and speed of computational techniques have provided a valuable opportunity for numerical simulations and complex experimental techniques to make a contribution to improving the diagnosis and clinical management of many forms of cardiovascular disease. This paper contains a review of recent progress in the numerical simulation of cardiovascular mechanics, focusing on three particular areas: patient-specific modeling and the optimization of surgery in pediatric cardiology, evaluating the risk of rupture in aortic aneurysms, and noninvasive characterization of intraventricular flow in the management of heart failure.
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Affiliation(s)
- Juan C Del Alamo
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, California, USA
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del Álamo JC, Marsden AL, Lasheras JC. Avances en mecánica computacional para el diagnóstico y tratamiento de la enfermedad cardiovascular. Rev Esp Cardiol 2009. [DOI: 10.1016/s0300-8932(09)71692-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Sundar H, Davatzikos C, Biros G. Biomechanically-constrained 4D estimation of myocardial motion. MEDICAL IMAGE COMPUTING AND COMPUTER-ASSISTED INTERVENTION : MICCAI ... INTERNATIONAL CONFERENCE ON MEDICAL IMAGE COMPUTING AND COMPUTER-ASSISTED INTERVENTION 2009; 12:257-65. [PMID: 20426120 DOI: 10.1007/978-3-642-04271-3_32] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
We propose a method for the analysis of cardiac images with the goal of reconstructing the motion of the ventricular walls. The main feature of our method is that the inversion parameter field is the active contraction of the myocardial fibers. This is accomplished with a biophysically-constrained, four-dimensional (space plus time) formulation that aims to complement information that can be gathered from the images by a priori knowledge of cardiac mechanics. Our main hypothesis is that by incorporating biophysical information, we can generate more informative priors and thus, more accurate predictions of the ventricular wall motion. In this paper, we outline the formulation, discuss the computational methodology for solving the inverse motion estimation, and present preliminary validation using synthetic and tagged MR images. The overall method uses patient-specific imaging and fiber information to reconstruct the motion. In these preliminary tests, we verify the implementation and conduct a parametric study to test the sensitivity of the model to material properties perturbations, model errors, and incomplete and noisy observations.
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Affiliation(s)
- Hari Sundar
- Section for Biomedical Image Analysis, Department of Radiology, University of Pennsylvania, USA
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Tang D, Yang C, Geva T, Del Nido PJ. Patient-specific MRI-based 3D FSI RV/LV/patch models for pulmonary valve replacement surgery and patch optimization. J Biomech Eng 2008; 130:041010. [PMID: 18601452 DOI: 10.1115/1.2913339] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A patient-specific right/left ventricle and patch (RV/LV/patch) combination model with fluid-structure interactions (FSIs) was introduced to evaluate and optimize human pulmonary valve replacement/insertion (PVR) surgical procedure and patch design. Cardiac magnetic resonance (CMR) imaging studies were performed to acquire ventricle geometry, flow velocity, and flow rate for healthy volunteers and patients needing RV remodeling and PVR before and after scheduled surgeries. CMR-based RV/LV/patch FSI models were constructed to perform mechanical analysis and assess RV cardiac functions. Both pre- and postoperation CMR data were used to adjust and validate the model so that predicted RV volumes reached good agreement with CMR measurements (error <3%). Two RV/LV/patch models were made based on preoperation data to evaluate and compare two PVR surgical procedures: (i) conventional patch with little or no scar tissue trimming, and (ii) small patch with aggressive scar trimming and RV volume reduction. Our modeling results indicated that (a) patient-specific CMR-based computational modeling can provide accurate assessment of RV cardiac functions, and (b) PVR with a smaller patch and more aggressive scar removal led to reduced stress/strain conditions in the patch area and may lead to improved recovery of RV functions. More patient studies are needed to validate our findings.
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Affiliation(s)
- Dalin Tang
- Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA 01609, USA.
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Raguin LG, Kodali AK, Rovas DV, Georgiadis JG. An inverse problem for reduced-encoding MRI velocimetry in potential flow. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2007; 2004:1100-3. [PMID: 17271875 DOI: 10.1109/iembs.2004.1403356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
We propose a computational technique to reconstruct internal physiological flows described by sparse point-wise MRI velocity measurements. Assuming that the viscous forces in the flow are negligible, the incompressible flow field can be obtained from a velocity potential that satisfies Laplace's equation. A set of basis functions each satisfying Laplace's equation with appropriately defined boundary data is constructed using the finite-element method. An inverse problem is formulated where higher resolution boundary and internal velocity data are extracted from the point-wise MRI velocity measurements using a least-squares method. From the results we obtained with approximately 100 internal measurement points, the proposed reconstruction method is shown to be effective in filtering out the experimental noise at levels as high as 30%, while matching the reference solution within 2%. This allows the reconstruction of a high-resolution velocity field with limited MRI encoding.
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Affiliation(s)
- L Guy Raguin
- Dept. of Mech. & Ind. Eng., Illinois Univ., Urbana, IL, USA
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Yang C, Tang D, Haber I, Geva T, del Nido PJ. In vivo MRI-Based 3D FSI RV/LV Models for Human Right Ventricle and Patch Design for Potential Computer-Aided Surgery Optimization. COMPUTERS & STRUCTURES 2007; 85:988-997. [PMID: 19809530 PMCID: PMC2757301 DOI: 10.1016/j.compstruc.2006.11.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Right ventricular dysfunction is one of the more common causes of heart failure in patients with congenital heart defects. Use of computer-assisted procedures is becoming more popular in clinical decision making process and computer-aided surgeries. A 3D in vivo MRI-based RV/LV combination model with fluid-structure interaction (FSI), RV-LV interaction, and RV-patch interaction was introduced to perform mechanical analysis for human right ventricle with potential clinical applications. Patient-specific RV/LV morphologies were acquired by using planar tagged MRI. The 3D RV/LV FSI model was solved using a commercial finite element package ADINA. Our results indicated that flow and stress/strain distributions in the right ventricle are closely related to RV morphology, material properties and blood pressure conditions. Patches with material properties better matching RV tissue properties and smaller size lead to better RV function recoveries. Computational RV volumes showed very good agreement with MRI data (error < 3%). More patient studies are needed to establish baseline database so that computational simulations can be used to replace empirical and often risky clinical experimentation to examine the efficiency and suitability of various reconstructive procedures in diseased hearts and optimal design can be found.
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Affiliation(s)
- Chun Yang
- Mathematics Department, Beijing Normal University, Beijing, China
| | - Dalin Tang
- Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester MA 01609
| | - Idith Haber
- Harvard Medical School, Department of Cardiac Surgery, Children’s Hospital, Boston, MA 02115
| | - Tal Geva
- Harvard Medical School, Department of Cardiac Surgery, Children’s Hospital, Boston, MA 02115
| | - Pedro J. del Nido
- Harvard Medical School, Department of Cardiac Surgery, Children’s Hospital, Boston, MA 02115
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Abstract
Magnetic resonance (MR) tagging is capable of accurate, noninvasive quantification of regional myocardial function. Routine clinical use, however, is hindered by cumbersome and time-consuming postprocessing procedures. We propose a fast, semiautomatic method for tracking three-dimensional (3-D) cardiac motion from a temporal sequence of short- and long-axis tagged MR images. The new method, called 3-D-HARmonic Phase (3D-HARP), extends the HARP approach, previously described for two-dimensional (2-D) tag analysis, to 3-D. A 3-D material mesh model is built to represent a collection of material points inside the left ventricle (LV) wall at a reference time. Harmonic phase, a material property that is time-invariant, is used to track the motion of the mesh through a cardiac cycle. Various motion-related functional properties of the myocardium, such as circumferential strain and left ventricular twist, are computed from the tracked mesh. The correlation analysis of 3D-HARP and FINDTAGS + Tag Strain(E) Analysis (TEA), which are well-established tag analysis techniques, shows that the regression coefficients of circumferential strain (E(CC)) and twist angle are r2 = 0.8605 and r2 = 0.8645, respectively. The total time required for tracking 3-D cardiac motion is approximately 10 min in a 9 timeframe tagged MRI dataset and has the potential to be much faster.
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Affiliation(s)
- Li Pan
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, 601 N. Caroline St. JHOC 4240, Baltimore, MD 21287, USA.
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Abstract
MR tagging is considered as a valuable technique to evaluate regional myocardial function quantitatively and noninvasively, however the cumbersome and time-consuming post-processing procedures for cardiac motion tracking still hinder its application to routine clinical examination. We present a fast and semiautomatic method for tracking 3D cardiac motion from short-axis (SA) and long-axis (LA) tagged MRI images. The technique, called 3D-HARP (HARmonic Phase), is based on the HARP method and extends this method to track 3D motion. A material mesh model is built to represent a collection of material points inside the left ventricle (LV) wall. The phase time-invariance property of material points is used to track the mesh points. For a series of 9 timeframe MRI images, the total time required for initializing settings, building the mesh, and tracking 3D cardiac motion is approximately 10 minutes. Further analysis of Langrangian strain and twist angle demonstrates that during systole, the lateral LV wall shows a greater strain values than the septum and the SA slices from the base to the apex show a gradual change in twist pattern.
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Affiliation(s)
- Li Pan
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD, USA.
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Current awareness in NMR in biomedicine. NMR IN BIOMEDICINE 2003; 16:56-65. [PMID: 12619641 DOI: 10.1002/nbm.799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
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