The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Mary E. Dickinson - One of the best experts on this subject based on the ideXlab platform.
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Visualization of early post-implantation mouse embryogenesis using 3D imaging modality (Conference Presentation)
Diagnosis and Treatment of Diseases in the Breast and Reproductive System, 2017Co-Authors: Chih-wei Hsu, Nanbing Li-villarreal, Victor G. Piazza, Sowmya Kalaga, Mary E. DickinsonAbstract:Hemodynamic Force is vital to cardiovascular remodeling in the early post-implantation mouse embryo. Here, we present work using microCT and lightsheet microscopy to establish the critical sequence of developmental events required for forming functional vasculature and circulation in the embryo, yolk sac, and placenta in the context of normal and impaired flow. A flow impaired model, Mlc2a+/- will be used to determine how Hemodynamic Force affects the specific events during embryonic development and vascular remodeling between the 4 and 29-somite stage using microCT. We have recently established high-resolution methods for the generation of 3D image volumes from the whole embryo within the deciduum (Hsu et al., in revision). This method enables the careful characterization of 3D images of vitelline and umbilical vessel remodeling to define how poor blood flow impacts both vitelline and umbilical vessel remodeling. Novel lightsheet live imaging techniques will be used to determine the consequence of impaired blood flow on yolk sac vasculature remodeling and formation of umbilical vessels using transgenic reporters: Flk-myr::mCherry, Flk1-H2B::YFP, or eGlobin-GFP. High-resolution 3D imaging of fixed and ScaleA2-cleared whole mount embryos labeled with Ki67 and Caspase3 will also be performed using lightsheet microscopy to quantify the proliferation and apoptotic indexes of early post-implanted embryos and yolk sac. This multi-modality approach is aimed at revealing further information about the cellular mechanisms required for proper vessel remodeling and the initial stages in placentation during early post-implantation development.
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The effects of Hemodynamic Force on embryonic development.
Microcirculation (New York N.Y. : 1994), 2010Co-Authors: James C. Culver, Mary E. DickinsonAbstract:Blood vessels have long been known to respond to Hemodynamic Force, and several mechanotransduction pathways have been identified. However, only recently have we begun to understand the effects of Hemodynamic Force on embryonic development. In this review, we will discuss specific examples illustrating the role of Hemodynamic Force during the development of the embryo, with particular focus on the development of the vascular system and the morphogenesis of the heart. We will also discuss the important functions served by mechanotransduction and Hemodynamic Force during placentation, as well as in regulating the maintenance and division of embryonic, hematopoietic, neural, and mesenchymal stem cells. Pathological misregulation of mechanosensitive pathways during pregnancy and embryonic development may contribute to the occurrence of cardiovascular birth defects, as well as to a variety of other diseases, including preeclampsia. Thus, there is a need for future studies focusing on better understanding the physiological effects of Hemodynamic Force during embryonic development and their role in the pathogenesis of disease.
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Vascular remodeling of the mouse yolk sac requires Hemodynamic Force
Journal of Cell Science, 2007Co-Authors: Jennifer L. Lucitti, Elizabeth A. V. Jones, Chengqun Huang, Ju Chen, Scott E. Fraser, Mary E. DickinsonAbstract:1. Lucitti et al. 2007. Development doi:10.1242/dev.02883 [OpenUrl][1][Abstract/FREE Full Text][2] [1]: {openurl}?query=rft.jtitle%253DDevelopment%26rft.stitle%253DDevelopment%26rft.issn%253D0950-1991%26rft.aulast%253DLucitti%26rft.auinit1%253DJ.%2BL.%26rft.volume%253D134%26rft.issue%
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Vascular remodeling of the mouse yolk sac requires Hemodynamic Force
Development (Cambridge England), 2007Co-Authors: Jennifer L. Lucitti, Elizabeth A. V. Jones, Chengqun Huang, Ju Chen, Scott E. Fraser, Mary E. DickinsonAbstract:The embryonic heart and vessels are dynamic and form and remodel while functional. Much has been learned about the genetic mechanisms underlying the development of the cardiovascular system, but we are just beginning to understand how changes in heart and vessel structure are influenced by Hemodynamic Forces such as shear stress. Recent work has shown that vessel remodeling in the mouse yolk sac is secondarily effected when cardiac function is reduced or absent. These findings indicate that proper circulation is required for vessel remodeling, but have not defined whether the role of circulation is to provide mechanical cues, to deliver oxygen or to circulate signaling molecules. Here, we used time-lapse confocal microscopy to determine the role of fluid-derived Forces in vessel remodeling in the developing murine yolk sac. Novel methods were used to characterize flows in normal embryos and in embryos with impaired contractility (Mlc2a^(–/–)). We found abnormal plasma and erythroblast circulation in these embryos, which led us to hypothesize that the entry of erythroblasts into circulation is a key event in triggering vessel remodeling. We tested this by sequestering erythroblasts in the blood islands, thereby lowering the hematocrit and reducing shear stress, and found that vessel remodeling and the expression of eNOS (Nos3) depends on erythroblast flow. Further, we rescued remodeling defects and eNOS expression in low-hematocrit embryos by restoring the viscosity of the blood. These data show that Hemodynamic Force is necessary and sufficient to induce vessel remodeling in the mammalian yolk sac
Irina V. Larina - One of the best experts on this subject based on the ideXlab platform.
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Corrigendum: Vascular development and Hemodynamic Force in the mouse yolk sac.
Frontiers in Physiology, 2014Co-Authors: Monica D. Garcia, Irina V. LarinaAbstract:The article “Vascular development and Hemodynamic Force in the mouse yolk sac” that is part of the research topic “Mechanotransduction and Development of Cardiovascular Form and Function” published 20 August 2014, is missing the following Acknowledgment Section:
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Vascular development and Hemodynamic Force in the mouse yolk sac
Frontiers in physiology, 2014Co-Authors: Monica D. Garcia, Irina V. LarinaAbstract:Vascular remodeling of the mouse embryonic yolk sac is a highly dynamic process dependent on multiple genetic signaling pathways as well as biomechanical factors regulating proliferation, differentiation, migration, cell-cell, and cell-matrix interactions. During this early developmental window, the initial primitive vascular network of the yolk sac undergoes a dynamic remodeling process concurrent with the onset of blood flow, in which endothelial cells establish a branched, hierarchical structure of large vessels and smaller capillary beds. In this review, we will describe the molecular and biomechanical regulators which guide vascular remodeling in the mouse embryonic yolk sac, as well as live imaging methods for characterizing endothelial cell and Hemodynamic function in cultured embryos.
Gianni Pedrizzetti - One of the best experts on this subject based on the ideXlab platform.
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Impact of synchronous atrioventricular delay optimization on left ventricle flow Force angle evaluated by echocardiographic particle image velocimetry
Journal of Interventional Cardiac Electrophysiology, 2021Co-Authors: Valter Bianchi, Gianni Pedrizzetti, Alfonso R. Martiniello, Jan Mangual, Vincenzo Tavoletta, Giovanni Tonti, Valentina Maria Caso, Pio Caso, Antonio D’onofrioAbstract:Purpose To evaluate the improvement in electrical synchrony and left ventricle (LV) Hemodynamics provided by combining the dynamic atrioventricular delay (AVD) of SyncAV^TM CRT and the multiple LV pacing sites of MultiPoint pacing (MPP). Methods Patients with LBBB and QRS duration (QRSd) > 140 ms implanted with a CRT-D or CRT-P device and quadripolar LV lead were enrolled in this prospective study. During a post-implant follow-up visit, QRSd was measured from 12-lead surface electrograms by experts blinded to pacing configurations. QRSd reduction relative to intrinsic rhythm was evaluated during biventricular pacing (BiV) and MPP for two AVDs: nominal (140/110 ms paced/sensed) and SyncAV (patient-optimized SyncAV offset [10–60 ms] minimizing QRSd). Echocardiography particle imaging velocimetry (Echo-PIV) analysis was performed for each configuration. The resulting Hemodynamic Force LV flow angle (φ) was analyzed, which ranges from 0^o (predominantly base-apex Forces) to 90^o (predominantly transverse Forces). Higher angles indicate more energy dissipation at lateral walls due to transverse flow; lower angles indicate healthier flow aligned with the longitudinal base-apex path of the pressure gradient. Results Twelve patients (58% male, 17% ischemic, 32±7% ejection fraction, 165 ± 18 ms intrinsic QRSd) completed QRSd and Echo-PIV assessment. Relative to intrinsic rhythm, BiV and MPP with nominal AVD reduced QRSd by 10 ± 9% and 12 ± 9%, respectively. BiV+SyncAV and MPP+SyncAV further reduced QRSd by 19 ± 8%, ( p < 0.05 vs. BiV with nominal AVD) and 23 ± 9% ( p < 0.05 vs BiV+SyncAV), respectively. Echo-PIV showed similar sequential Hemodynamic improvements. LV flow angular orientation during intrinsic activation (46 ± 3^o) reduced with BiV+SyncAV (37 ± 4^o, p < 0.05 vs intrinsic) and further with MPP+SyncAV (34 ± 4^o, p < 0.05 vs BiV+SyncAV). Conclusion These results suggest that SyncAV may improve electrical synchrony and influence LV flow patterns in patients suffering from heart failure compared to conventional CRT with a fixed AVD, with further improvement observed by combining with MPP.
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P737 Left ventricular Hemodynamic Forces: towards establishing reference values for healthy adults
European Heart Journal - Cardiovascular Imaging, 2020Co-Authors: Francesco Capuano, Rosangela Cocchia, Francesco Ferrara, S Lanero, Valentina Russo, B Ranieri, C Contaldi, C Sepe, G Mirto, Gianni PedrizzettiAbstract:Abstract Introduction Left ventricular Hemodynamic Forces (LV-HDF) have been recently demonstrated to be promising markers of sub-clinical dysfunction and potential predictors of disease outcome. However, there is a lack of reference values in healthy subjects. Knowledge of physiologic ranges is mandatory towards the use of LV-HDF-based indices for disease assessment in future clinical applications. Purpose Aim of the current study is to define the normal reference values for LV-HDF parameters in a large cohort of healthy adults. Here we present preliminary results for the initial set of enrolled subjects. Methods We enrolled 82 healthy subjects [mean age 44 ± 13.2 years (range 18-88), 41 men]. All participants underwent standard transthoracic echocardiography (TTE) examination, as recommended by current guidelines, including apical two-, three- and four-chamber windows, acquired at a frame rate above 40 Hz. These were then analyzed by tri-plane tissue tracking, measuring LV volume and LV ejection fraction (EF) as reference parameters. The same tracking method was used to evaluate the global Hemodynamic Force by a novel mathematical calculation technique applied to the three-dimensional endocardial contour. Physical-based LV-HDF parameters were then extracted for clinical application; these included the amplitude (root mean square) of the longitudinal and transversal Force components (FL and FT) and their alignment angle relative to the LV axis. Parameters were computed as average over the whole cardiac cycle as well as limited to the systolic phase. Forces were normalized with LV volume to reduce variability with LV dimension, and divided by specific weight to yield a dimensionless measure. Results Mean EF was 63 ± 9%. Whole cycle LV-HDF parameters were: FL = 16.0 ± 5.6%, FT = 2.3 ± 0.8%, with significant longitudinal alignment FT/FL = 0.15 ± 0.04, angle = 13.0°±3.1°. Systolic HDF parameters were: FL = 22.7 ± 8.2%, FT = 2.9 ± 1.1%, with longitudinal alignment FT/FL = 0.13 ± 0.04, angle = 11.2°±3.1°. Importantly, dimensionless physical-based LV-HDF parameters showed no significant variation with age, gender or BSA. Conclusions We report the physiologic range of LV-HDF parameters measured by TTE. Knowledge of age- and gender-specific reference values, for a combination of standard, mechanical and Hemodynamic indices, can improve the global assessment of the LV function and may help to detect sub-clinical stages of LV dysfunction.
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Hemodynamic Forces using four-dimensional flow MRI: an independent biomarker of cardiac function in heart failure with left ventricular dyssynchrony?
American journal of physiology. Heart and circulatory physiology, 2018Co-Authors: Per M Arvidsson, Johannes Toger, Einar Heiberg, Marcus Carlsson, Rasmus Borgquist, Gianni Pedrizzetti, Hakan ArhedenAbstract:Patients with heart failure with left ventricular (LV) dyssynchrony often do not respond to cardiac resynchronization therapy (CRT), indicating that the pathophysiology is insufficiently understood. Intracardiac Hemodynamic Forces computed from four-dimensional (4-D) flow MRI have been proposed as a new measure of cardiac function. We therefore aimed to investigate how Hemodynamic Forces are altered in LV dyssynchrony. Thirty-one patients with heart failure and LV dyssynchrony and 39 control subjects underwent cardiac MRI with the acquisition of 4-D flow. Hemodynamic Forces were computed using Navier-Stokes equations and integrated over the manually delineated LV volume. The ratio between transverse (lateral-septal and inferior-anterior) and longitudinal (apical-basal) Forces was calculated for systole and diastole separately and compared with QRS duration, aortic valve opening delay, global longitudinal strain, and ejection fraction (EF). Patients exhibited Hemodynamic Force patterns that were significantly altered compared with control subjects, including loss of longitudinal Forces in diastole (Force ratio, control subjects vs. patients: 0.32 vs. 0.90, P < 0.0001) and increased transverse Force magnitudes. The systolic Force ratio was correlated with global longitudinal strain and EF ( P < 0.01). The diastolic Force ratio separated patients from control subjects (area under the curve: 0.98, P < 0.0001) but was not correlated to other dyssynchrony measures ( P > 0.05 for all). Hemodynamic Forces by 4-D flow represent a new approach to the quantification of LV dyssynchrony. Diastolic Force patterns separate healthy from diseased ventricles. Different Force patterns in patients indicate the possible use of Force analysis for risk stratification and CRT implantation guidance. NEW & NOTEWORTHY In this report, we demonstrate that patients with heart failure with left ventricular dyssynchrony exhibit significantly altered Hemodynamic Forces compared with normal. Force patterns in patients mechanistically reflect left ventricular dysfunction on the organ level, largely independent of traditional dyssynchrony measures. Force analysis may help clinical decision making and could potentially be used to improve therapy outcomes.
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Hemodynamic Forces in the left and right ventricles of the human heart using 4D flow magnetic resonance imaging: Phantom validation, reproducibility, sensitivity to respiratory gating and free analysis software.
PloS one, 2018Co-Authors: Johannes Toger, Per M Arvidsson, Marcus Carlsson, Hakan Arheden, Gianni Pedrizzetti, Jelena Bock, Mikael Kanski, Einar HeibergAbstract:Purpose To investigate the accuracy, reproducibility and sensitivity to respiratory gating, field strength and ventricle segmentation of Hemodynamic Force quantification in the left and right ventricles of the heart (LV and RV) using 4D-flow magnetic resonance imaging (MRI), and to provide free Hemodynamic Force analysis software. Materials and methods A pulsatile flow phantom was imaged using 4D flow MRI and laser-based particle image velocimetry (PIV). Cardiac 4D flow MRI was performed in healthy volunteers at 1.5T (n = 23). Reproducibility was investigated using MR scanners from two different vendors on the same day (n = 8). Subsets of volunteers were also imaged without respiratory gating (n = 17), at 3T on the same day (n = 6), and 1–12 days later on the same scanner (n = 9, median 6 days). Agreement was measured using the intraclass correlation coefficient (ICC). Results Phantom validation showed good accuracy for both scanners (Scanner 1: bias -14±9%, y = 0.82x+0.08, R2 = 0.96, Scanner 2: bias -12±8%, y = 0.99x-0.08, R2 = 1.00). Force reproducibility was strong in the LV (0.09±0.07 vs 0.09±0.07 N, bias 0.00±0.04 N, ICC = 0.87) and RV (0.09±0.06 vs 0.09±0.05 N, bias 0.00±0.03, ICC = 0.83). Strong to very strong agreement was found for scans with and without respiratory gating (LV/RV: ICC = 0.94/0.95), scans on different days (ICC = 0.92/0.87), and 1.5T and 3T scans (ICC = 0.93/0.94). Conclusion Software for quantification of Hemodynamic Forces in 4D-flow MRI was developed, and results show high accuracy and strong to very strong reproducibility for both the LV and RV, supporting its use for research and clinical investigations. The software including source code is released freely for research. (Less)
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Hemodynamic Force curves from all subjects.
2018Co-Authors: Johannes Toger, Per M Arvidsson, Marcus Carlsson, Hakan Arheden, Gianni Pedrizzetti, Jelena Bock, Mikael Kanski, Einar HeibergAbstract:Panel a) shows mean LV Force curves for all three directions, including 95% confidence intervals (CI) for the mean Force at each point in the cardiac cycle. Panel b) shows mean RV Force curves for all three directions. Panel c) shows the ratio between longitudinal and transverse Forces in systole and diastole in the LV and RV (based on RMS Forces). Panel d) shows mean transmitral and aortic flow in all subjects as a reference for timing of Hemodynamic Forces with respect to intracardiac flow. E1 = first half of early rapid filling of LV, time fraction 0.393–0.529, E2 = second half of early rapid filling of LV, time fraction 0.529–0.664.
Hakan Arheden - One of the best experts on this subject based on the ideXlab platform.
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Intraventricular Hemodynamic Forces do not differentiate between healthy controls and heart failure patients with preserved ejection fraction
European Heart Journal, 2020Co-Authors: Per M Arvidsson, Marcus Carlsson, A Nelsson, Martin Magnusson, J. G. Smith, Hakan ArhedenAbstract:Abstract Background Hemodynamic Force analysis has been proposed as a noninvasive marker of cardiac function. In a recent study, longitudinal (apical-to-basal) Hemodynamic Forces were derived from anatomical MRI images and found decreased in heart failure with preserved ejection fraction (HFpEF) patients compared to controls, indicating a potential use for prognostication and testing of therapeutic response. This issue has not been investigated using the reference method of measurement. Purpose To investigate whether intraventricular Hemodynamic Forces computed using gold-standard cardiac magnetic resonance flow maps can reproducibly differentiate between healthy controls and HFpEF patients. Methods 4D flow data were acquired in 59 subjects through cardiac magnetic resonance imaging using a 1.5T scanner (Siemens Healthcare, Erlangen, Germany). Hemodynamic Forces within the LV were computed across the cardiac cycle using the Navier-Stokes equation to find the global pressure gradient, which was then integrated over the LV volume to produce the instantaneous Hemodynamic Force (unit: Newton) and subsequently normalized to ventricular volume, resulting in a Force-volume index (N/l). Average longitudinal Forces (root mean square, FRMS) were quantified over the entire cardiac cycle, with and without volume normalization. Results We studied 33 healthy subjects, 14 patients with HFpEF, 6 patients with HFmEF and 6 patients with HFrEF. Groups were similar with regards to sex, cardiac output, heart rate, systolic and diastolic blood pressure, and body surface area. Volume-normalized FRMS did not differ between controls and HFpEF (0.86±0.19 vs. 0.75±0.19 N/l, p=0.08) while lower values were found in HFmEF (0.60±0.19 N/l, p=0.004) and HFrEF (0.38±0.15 N/l, p<0.0001) compared to controls (Figure 1A). There was a significant positive correlation between EF and FRMS, both for the entire population (R2 = 0.54, Figure 1B) and for patients (R2 = 0.67, p<0.0001 for both). Importantly, non-normalized FRMS did not differ between controls (Figure 1C, 0.10±0.03 N) and HFpEF (0.09±0.03 N, p=0.25), HFmEF (0.11±0.02 N, p=0.18) or HFrEF (0.09±0.02 N, p=0.67). Moreover, no correlation was seen between non-normalized FRMS and EF (Figure 1D). Conclusions Hemodynamic Forces computed from reference standard 4D flow CMR data do not differentiate between healthy controls and HFpEF patients regardless of whether volume normalization is used or not. Our findings do not support a role for Hemodynamic Forces in HFpEF assessment. Figure 1. (A) Volume-normalized Hemodynamic Forces over the entire cardiac cycle (lines: average values, shaded area: ±1SD for HFpEF), and (B) variation of volume-normalized average Force, FRMS, with left ventricular ejection fraction (LVEF). (C), (D): When indexing to LV volume was not performed, the differences between groups was attenuated, and no correlation was seen between EF and FRMS. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Swedish Heart and Lung Foundation, Region of Scania
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Hemodynamic Forces using four-dimensional flow MRI: an independent biomarker of cardiac function in heart failure with left ventricular dyssynchrony?
American journal of physiology. Heart and circulatory physiology, 2018Co-Authors: Per M Arvidsson, Johannes Toger, Einar Heiberg, Marcus Carlsson, Rasmus Borgquist, Gianni Pedrizzetti, Hakan ArhedenAbstract:Patients with heart failure with left ventricular (LV) dyssynchrony often do not respond to cardiac resynchronization therapy (CRT), indicating that the pathophysiology is insufficiently understood. Intracardiac Hemodynamic Forces computed from four-dimensional (4-D) flow MRI have been proposed as a new measure of cardiac function. We therefore aimed to investigate how Hemodynamic Forces are altered in LV dyssynchrony. Thirty-one patients with heart failure and LV dyssynchrony and 39 control subjects underwent cardiac MRI with the acquisition of 4-D flow. Hemodynamic Forces were computed using Navier-Stokes equations and integrated over the manually delineated LV volume. The ratio between transverse (lateral-septal and inferior-anterior) and longitudinal (apical-basal) Forces was calculated for systole and diastole separately and compared with QRS duration, aortic valve opening delay, global longitudinal strain, and ejection fraction (EF). Patients exhibited Hemodynamic Force patterns that were significantly altered compared with control subjects, including loss of longitudinal Forces in diastole (Force ratio, control subjects vs. patients: 0.32 vs. 0.90, P < 0.0001) and increased transverse Force magnitudes. The systolic Force ratio was correlated with global longitudinal strain and EF ( P < 0.01). The diastolic Force ratio separated patients from control subjects (area under the curve: 0.98, P < 0.0001) but was not correlated to other dyssynchrony measures ( P > 0.05 for all). Hemodynamic Forces by 4-D flow represent a new approach to the quantification of LV dyssynchrony. Diastolic Force patterns separate healthy from diseased ventricles. Different Force patterns in patients indicate the possible use of Force analysis for risk stratification and CRT implantation guidance. NEW & NOTEWORTHY In this report, we demonstrate that patients with heart failure with left ventricular dyssynchrony exhibit significantly altered Hemodynamic Forces compared with normal. Force patterns in patients mechanistically reflect left ventricular dysfunction on the organ level, largely independent of traditional dyssynchrony measures. Force analysis may help clinical decision making and could potentially be used to improve therapy outcomes.
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Hemodynamic Forces in the left and right ventricles of the human heart using 4D flow magnetic resonance imaging: Phantom validation, reproducibility, sensitivity to respiratory gating and free analysis software.
PloS one, 2018Co-Authors: Johannes Toger, Per M Arvidsson, Marcus Carlsson, Hakan Arheden, Gianni Pedrizzetti, Jelena Bock, Mikael Kanski, Einar HeibergAbstract:Purpose To investigate the accuracy, reproducibility and sensitivity to respiratory gating, field strength and ventricle segmentation of Hemodynamic Force quantification in the left and right ventricles of the heart (LV and RV) using 4D-flow magnetic resonance imaging (MRI), and to provide free Hemodynamic Force analysis software. Materials and methods A pulsatile flow phantom was imaged using 4D flow MRI and laser-based particle image velocimetry (PIV). Cardiac 4D flow MRI was performed in healthy volunteers at 1.5T (n = 23). Reproducibility was investigated using MR scanners from two different vendors on the same day (n = 8). Subsets of volunteers were also imaged without respiratory gating (n = 17), at 3T on the same day (n = 6), and 1–12 days later on the same scanner (n = 9, median 6 days). Agreement was measured using the intraclass correlation coefficient (ICC). Results Phantom validation showed good accuracy for both scanners (Scanner 1: bias -14±9%, y = 0.82x+0.08, R2 = 0.96, Scanner 2: bias -12±8%, y = 0.99x-0.08, R2 = 1.00). Force reproducibility was strong in the LV (0.09±0.07 vs 0.09±0.07 N, bias 0.00±0.04 N, ICC = 0.87) and RV (0.09±0.06 vs 0.09±0.05 N, bias 0.00±0.03, ICC = 0.83). Strong to very strong agreement was found for scans with and without respiratory gating (LV/RV: ICC = 0.94/0.95), scans on different days (ICC = 0.92/0.87), and 1.5T and 3T scans (ICC = 0.93/0.94). Conclusion Software for quantification of Hemodynamic Forces in 4D-flow MRI was developed, and results show high accuracy and strong to very strong reproducibility for both the LV and RV, supporting its use for research and clinical investigations. The software including source code is released freely for research. (Less)
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Hemodynamic Force curves from all subjects.
2018Co-Authors: Johannes Toger, Per M Arvidsson, Marcus Carlsson, Hakan Arheden, Gianni Pedrizzetti, Jelena Bock, Mikael Kanski, Einar HeibergAbstract:Panel a) shows mean LV Force curves for all three directions, including 95% confidence intervals (CI) for the mean Force at each point in the cardiac cycle. Panel b) shows mean RV Force curves for all three directions. Panel c) shows the ratio between longitudinal and transverse Forces in systole and diastole in the LV and RV (based on RMS Forces). Panel d) shows mean transmitral and aortic flow in all subjects as a reference for timing of Hemodynamic Forces with respect to intracardiac flow. E1 = first half of early rapid filling of LV, time fraction 0.393–0.529, E2 = second half of early rapid filling of LV, time fraction 0.529–0.664.
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Visualization of LV Hemodynamic Forces and relative pressure fields in a healthy volunteer.
2018Co-Authors: Johannes Toger, Per M Arvidsson, Marcus Carlsson, Hakan Arheden, Gianni Pedrizzetti, Jelena Bock, Mikael Kanski, Einar HeibergAbstract:Panel a) shows the basal-apical component of the Hemodynamic Force and panels b), c), and d) show the relative pressure field and the Hemodynamic Force vector (white arrow) in three timeframes. The positive basal-apical Force component during early systole corresponds to the high apical pressure and low basal pressure in Fig 4B and similarly for Fig 4D. In Fig 4C, the negative basal-apical Force is reflected in the low apical pressure and high basal pressure. An animated version is available in Supporting File S1 Movie. E1 = first half of early rapid filling of LV, time fraction 0.393–0.529, E2 = second half of early rapid filling of LV, time fraction 0.529–0.664.
Einar Heiberg - One of the best experts on this subject based on the ideXlab platform.
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Hemodynamic Forces using four-dimensional flow MRI: an independent biomarker of cardiac function in heart failure with left ventricular dyssynchrony?
American journal of physiology. Heart and circulatory physiology, 2018Co-Authors: Per M Arvidsson, Johannes Toger, Einar Heiberg, Marcus Carlsson, Rasmus Borgquist, Gianni Pedrizzetti, Hakan ArhedenAbstract:Patients with heart failure with left ventricular (LV) dyssynchrony often do not respond to cardiac resynchronization therapy (CRT), indicating that the pathophysiology is insufficiently understood. Intracardiac Hemodynamic Forces computed from four-dimensional (4-D) flow MRI have been proposed as a new measure of cardiac function. We therefore aimed to investigate how Hemodynamic Forces are altered in LV dyssynchrony. Thirty-one patients with heart failure and LV dyssynchrony and 39 control subjects underwent cardiac MRI with the acquisition of 4-D flow. Hemodynamic Forces were computed using Navier-Stokes equations and integrated over the manually delineated LV volume. The ratio between transverse (lateral-septal and inferior-anterior) and longitudinal (apical-basal) Forces was calculated for systole and diastole separately and compared with QRS duration, aortic valve opening delay, global longitudinal strain, and ejection fraction (EF). Patients exhibited Hemodynamic Force patterns that were significantly altered compared with control subjects, including loss of longitudinal Forces in diastole (Force ratio, control subjects vs. patients: 0.32 vs. 0.90, P < 0.0001) and increased transverse Force magnitudes. The systolic Force ratio was correlated with global longitudinal strain and EF ( P < 0.01). The diastolic Force ratio separated patients from control subjects (area under the curve: 0.98, P < 0.0001) but was not correlated to other dyssynchrony measures ( P > 0.05 for all). Hemodynamic Forces by 4-D flow represent a new approach to the quantification of LV dyssynchrony. Diastolic Force patterns separate healthy from diseased ventricles. Different Force patterns in patients indicate the possible use of Force analysis for risk stratification and CRT implantation guidance. NEW & NOTEWORTHY In this report, we demonstrate that patients with heart failure with left ventricular dyssynchrony exhibit significantly altered Hemodynamic Forces compared with normal. Force patterns in patients mechanistically reflect left ventricular dysfunction on the organ level, largely independent of traditional dyssynchrony measures. Force analysis may help clinical decision making and could potentially be used to improve therapy outcomes.
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Hemodynamic Forces in the left and right ventricles of the human heart using 4D flow magnetic resonance imaging: Phantom validation, reproducibility, sensitivity to respiratory gating and free analysis software.
PloS one, 2018Co-Authors: Johannes Toger, Per M Arvidsson, Marcus Carlsson, Hakan Arheden, Gianni Pedrizzetti, Jelena Bock, Mikael Kanski, Einar HeibergAbstract:Purpose To investigate the accuracy, reproducibility and sensitivity to respiratory gating, field strength and ventricle segmentation of Hemodynamic Force quantification in the left and right ventricles of the heart (LV and RV) using 4D-flow magnetic resonance imaging (MRI), and to provide free Hemodynamic Force analysis software. Materials and methods A pulsatile flow phantom was imaged using 4D flow MRI and laser-based particle image velocimetry (PIV). Cardiac 4D flow MRI was performed in healthy volunteers at 1.5T (n = 23). Reproducibility was investigated using MR scanners from two different vendors on the same day (n = 8). Subsets of volunteers were also imaged without respiratory gating (n = 17), at 3T on the same day (n = 6), and 1–12 days later on the same scanner (n = 9, median 6 days). Agreement was measured using the intraclass correlation coefficient (ICC). Results Phantom validation showed good accuracy for both scanners (Scanner 1: bias -14±9%, y = 0.82x+0.08, R2 = 0.96, Scanner 2: bias -12±8%, y = 0.99x-0.08, R2 = 1.00). Force reproducibility was strong in the LV (0.09±0.07 vs 0.09±0.07 N, bias 0.00±0.04 N, ICC = 0.87) and RV (0.09±0.06 vs 0.09±0.05 N, bias 0.00±0.03, ICC = 0.83). Strong to very strong agreement was found for scans with and without respiratory gating (LV/RV: ICC = 0.94/0.95), scans on different days (ICC = 0.92/0.87), and 1.5T and 3T scans (ICC = 0.93/0.94). Conclusion Software for quantification of Hemodynamic Forces in 4D-flow MRI was developed, and results show high accuracy and strong to very strong reproducibility for both the LV and RV, supporting its use for research and clinical investigations. The software including source code is released freely for research. (Less)
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Hemodynamic Force curves from all subjects.
2018Co-Authors: Johannes Toger, Per M Arvidsson, Marcus Carlsson, Hakan Arheden, Gianni Pedrizzetti, Jelena Bock, Mikael Kanski, Einar HeibergAbstract:Panel a) shows mean LV Force curves for all three directions, including 95% confidence intervals (CI) for the mean Force at each point in the cardiac cycle. Panel b) shows mean RV Force curves for all three directions. Panel c) shows the ratio between longitudinal and transverse Forces in systole and diastole in the LV and RV (based on RMS Forces). Panel d) shows mean transmitral and aortic flow in all subjects as a reference for timing of Hemodynamic Forces with respect to intracardiac flow. E1 = first half of early rapid filling of LV, time fraction 0.393–0.529, E2 = second half of early rapid filling of LV, time fraction 0.529–0.664.
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Visualization of LV Hemodynamic Forces and relative pressure fields in a healthy volunteer.
2018Co-Authors: Johannes Toger, Per M Arvidsson, Marcus Carlsson, Hakan Arheden, Gianni Pedrizzetti, Jelena Bock, Mikael Kanski, Einar HeibergAbstract:Panel a) shows the basal-apical component of the Hemodynamic Force and panels b), c), and d) show the relative pressure field and the Hemodynamic Force vector (white arrow) in three timeframes. The positive basal-apical Force component during early systole corresponds to the high apical pressure and low basal pressure in Fig 4B and similarly for Fig 4D. In Fig 4C, the negative basal-apical Force is reflected in the low apical pressure and high basal pressure. An animated version is available in Supporting File S1 Movie. E1 = first half of early rapid filling of LV, time fraction 0.393–0.529, E2 = second half of early rapid filling of LV, time fraction 0.529–0.664.
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Phantom validation of Hemodynamic Forces.
2018Co-Authors: Johannes Toger, Per M Arvidsson, Marcus Carlsson, Hakan Arheden, Gianni Pedrizzetti, Jelena Bock, Mikael Kanski, Einar HeibergAbstract:A pulsatile flow phantom [7] (Panel a) was imaged with a laser-based technique (PIV, particle image velocimetry) and 4D flow MRI. Panels b) and c) show the pressure gradient at one time instant computed from PIV and 4D flow velocities, respectively. Panel d) shows Hemodynamic Force curves for one pump setting (out of five). Panel e) shows a summary of results for RMS and peak Forces on the both scanners, with a slight underestimation for both scanners.