Browsing by Author "Sotelo, Julio"

Now showing 1 - 14 of 14
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    A comprehensive comparison between shortest-path HARP refinement, SinMod, and DENSEanalysis processing tools applied to CSPAMM and DENSE images
    (2021) Mella, Hernan; Mura, Joaquin; Sotelo, Julio; Uribe, Sergio
    We addressed comprehensively the performance of Shortest-Path HARP Refinement (SP-HR), SinMod, and DENSEanalysis using 2D slices of synthetic CSPAMM and DENSE images with realistic contrasts obtained from 3D phantoms. The three motion estimation techniques were interrogated under ideal and no-ideal conditions (with MR induced artifacts, noise, and through-plane motion), considering several resolutions and noise levels. Under noisy conditions, and for isotropic pixel sizes of 1.5 mm and 3.0 mm in CSPAMM and DENSE images respectively, the nRMSE obtained for the circumferential and radial strain components were 10.7 +/- 10.8% and 25.5 +/- 14.8% using SP-HR, 11.9 +/- 2.5% and 29.3 +/- 6.5% using SinMod, and 6.4 +/- 2.0% and 18.2 +/- 4.6% using DENSEanalysis. Overall, the results showed that SP-HR tends to fail for large tissue motions, whereas SinMod and DENSEanalysis gave accurate displacement and strain field estimations, being the last which performed the best.
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    Altered Aortic Hemodynamics and Relative Pressure in Patients with Dilated Cardiomyopathy
    (2022) Marlevi, David; Mariscal-Harana, Jorge; Burris, Nicholas S.; Sotelo, Julio; Ruijsink, Bram; Hadjicharalambous, Myrianthi; Asner, Liya; Sammut, Eva; Chabiniok, Radomir; Uribe, Sergio; Winter, Reidar; Lamata, Pablo; Alastruey, Jordi; Nordsletten, David
    Ventricular-vascular interaction is central in the adaptation to cardiovascular disease. However, cardiomyopathy patients are predominantly monitored using cardiac biomarkers. The aim of this study is therefore to explore aortic function in dilated cardiomyopathy (DCM). Fourteen idiopathic DCM patients and 16 controls underwent cardiac magnetic resonance imaging, with aortic relative pressure derived using physics-based image processing and a virtual cohort utilized to assess the impact of cardiovascular properties on aortic behaviour. Subjects with reduced left ventricular systolic function had significantly reduced aortic relative pressure, increased aortic stiffness, and significantly delayed time-to-pressure peak duration. From the virtual cohort, aortic stiffness and aortic volumetric size were identified as key determinants of aortic relative pressure. As such, this study shows how advanced flow imaging and aortic hemodynamic evaluation could provide novel insights into the manifestation of DCM, with signs of both altered aortic structure and function derived in DCM using our proposed imaging protocol.
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    Aortic Stenosis: Haemodynamic Benchmark and Metric Reliability Study
    (2023) Gill, Harminder; Fernandes, Joao Filipe; Nio, Amanda; Dockerill, Cameron; Shah, Nili; Ahmed, Naajia; Raymond, Jason; Wang, Shu; Sotelo, Julio; Urbina, Jesus; Uribe, Sergio; Rajani, Ronak; Rhode, Kawal; Lamata, Pablo
    Aortic stenosis is a condition which is fatal if left untreated. Novel quantitative imaging techniques which better characterise transvalvular pressure drops are being developed but require refinement and validation. A customisable and cost-effective workbench valve phantom circuit capable of replicating valve mechanics and pathology was created. The reproducibility and relationship of differing haemodynamic metrics were assessed from ground truth pressure data alongside imaging compatibility. The phantom met the requirements to capture ground truth pressure data alongside ultrasound and magnetic resonance image compatibility. The reproducibility was successfully tested. The robustness of three different pressure drop metrics was assessed: whilst the peak and net pressure drops provide a robust assessment of the stenotic burden in our phantom, the peak-to-peak pressure drop is a metric that is confounded by non-valvular factors such as wave reflection. The peak-to-peak pressure drop is a metric that should be reconsidered in clinical practice.
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    Assessment of 4D flow MRI's quality by verifying its Navier-Stokes compatibility
    (2022) Garay, Jeremias; Mella, Hernan; Sotelo, Julio; Carcamo, Cristian; Uribe, Sergio; Bertoglio, Cristobal; Mura, Joaquin
    4D Flow Magnetic Resonance Imaging (MRI) is the state-of-the-art technique to comprehensively measure the complex spatio-temporal and multidirectional patterns of blood flow. However, it is subject to artifacts such as noise and aliasing, which due to the 3D and dynamic structure is difficult to detect in clinical practice. In this work, a new mathematical and computational model to determine the quality of 4D Flow MRI is presented. The model is derived by assuming the true velocity satisfies the incompressible Navier-Stokes equations and that can be decomposed by the measurements u -> meas$$ {\overrightarrow{u}}_{meas} $$ plus an extra field w ->$$ \overrightarrow{w} $$. Therefore, a non-linear problem with w ->$$ \overrightarrow{w} $$ as unknown arises, which serves as a measure of data quality. A stabilized finite element formulation tailored to this problem is proposed and analyzed. Then, extensive numerical examples-using synthetic 4D Flow MRI data as well as real measurements on experimental phantom and subjects-illustrate the ability to use w ->$$ \overrightarrow{w} $$ for assessing the quality of 4D Flow MRI measurements over space and time.
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    Comprehensive Assessment of Left Intraventricular Hemodynamics Using a Finite Element Method: An Application to Dilated Cardiomyopathy Patients
    (2021) Franco, Pamela; Sotelo, Julio; Montalba, Cristian; Ruijsink, Bram; Kerfoot, Eric; Nordsletten, David; Mura, Joaquin; Hurtado, Daniel; Uribe, Sergio
    In this paper, we applied a method for quantifying several left intraventricular hemodynamic parameters from 4D Flow data and its application in a proof-of-concept study in dilated cardiomyopathy (DCM) patients. In total, 12 healthy volunteers and 13 DCM patients under treatment underwent short-axis cine b-SSFP and 4D Flow MRI. Following 3D segmentation of the left ventricular (LV) cavity and registration of both sequences, several hemodynamic parameters were calculated at peak systole, e-wave, and end-diastole using a finite element approach. Sensitivity, inter- and intra-observer reproducibility of hemodynamic parameters were evaluated by analyzing LV segmentation. A local analysis was performed by dividing the LV cavity into 16 regions. We found significant differences between volunteers and patients in velocity, vorticity, viscous dissipation, energy loss, and kinetic energy at peak systole and e-wave. Furthermore, although five patients showed a recovered ejection fraction after treatment, their hemodynamic parameters remained low. We obtained several hemodynamic parameters with high inter- and intra-observer reproducibility. The sensitivity study revealed that hemodynamic parameters showed a higher accuracy when the segmentation underestimates the LV volumes. Our approach was able to identify abnormal flow patterns in DCM patients compared to volunteers and can be applied to any other cardiovascular diseases.
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    Fully Three-Dimensional Hemodynamic Characterization of Altered Blood Flow in Bicuspid Aortic Valve Patients With Respect to Aortic Dilatation: A Finite Element Approach
    (2022) Sotelo, Julio; Franco, Pamela; Guala, Andrea; Dux-Santoy, Lydia; Ruiz-Munoz, Aroa; Evangelista, Arturo; Mella, Hernan; Mura, Joaquin; Hurtado, Daniel E.; Rodriguez-Palomares, Jose F.; Uribe, Sergio
    Background and PurposePrognostic models based on cardiovascular hemodynamic parameters may bring new information for an early assessment of patients with bicuspid aortic valve (BAV), playing a key role in reducing the long-term risk of cardiovascular events. This work quantifies several three-dimensional hemodynamic parameters in different patients with BAV and ranks their relationships with aortic diameter. Materials and MethodsUsing 4D-flow CMR data of 74 patients with BAV (49 right-left and 25 right-non-coronary) and 48 healthy volunteers, aortic 3D maps of seventeen 17 different hemodynamic parameters were quantified along the thoracic aorta. Patients with BAV were divided into two morphotype categories, BAV-Non-AAoD (where we include 18 non-dilated patients and 7 root-dilated patients) and BAV-AAoD (where we include the 49 patients with dilatation of the ascending aorta). Differences between volunteers and patients were evaluated using MANOVA with Pillai's trace statistic, Mann-Whitney U test, ROC curves, and minimum redundancy maximum relevance algorithm. Spearman's correlation was used to correlate the dilation with each hemodynamic parameter. ResultsThe flow eccentricity, backward velocity, velocity angle, regurgitation fraction, circumferential wall shear stress, axial vorticity, and axial circulation allowed to discriminate between volunteers and patients with BAV, even in the absence of dilation. In patients with BAV, the diameter presented a strong correlation (> |+/-0.7|) with the forward velocity and velocity angle, and a good correlation (> |+/-0.5|) with regurgitation fraction, wall shear stress, wall shear stress axial, and vorticity, also for morphotypes and phenotypes, some of them are correlated with the diameter. The velocity angle proved to be an excellent biomarker in the differentiation between volunteers and patients with BAV, BAV morphotypes, and BAV phenotypes, with an area under the curve bigger than 0.90, and higher predictor important scores. ConclusionsThrough the application of a novel 3D quantification method, hemodynamic parameters related to flow direction, such as flow eccentricity, velocity angle, and regurgitation fraction, presented the best relationships with a local diameter and effectively differentiated patients with BAV from healthy volunteers.
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    Identification of hemodynamic biomarkers for bicuspid aortic valve induced aortic dilation using machine learning
    (2022) Franco, Pamela; Sotelo, Julio; Guala, Andrea; Dux-Santoy, Lydia; Evangelista, Arturo; Rodriguez-Palomares, Jose; Mery Quiroz, Domingo Arturo; Salas, Rodrigo; Uribe, Sergio
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    Impact of aortic arch curvature in flow haemodynamics in patients with transposition of the great arteries after arterial switch operation
    (2022) Sotelo, Julio; Valverde, Israel; Martins, Duarte; Bonnet, Damien; Boddaert, Nathalie; Pushparajan, Kuberan; Uribe, Sergio; Raimondi, Francesca
    Aims In this study, we will describe a comprehensive haemodynamic analysis and its relationship to the dilation of the aorta in transposition of the great artery (TGA) patients post-arterial switch operation (ASO) and controls using 4D-flow magnetic resonance imaging (MRI) data. Methods and results Using 4D-flow MRI data of 14 TGA young patients and 8 age-matched normal controls obtained with 1.5 T GE-MR scanner, we evaluate 3D maps of 15 different haemodynamics parameters in six regions; three of them in the aortic root and three of them in the ascending aorta (anterior-left, -right, and posterior for both cases) to find its relationship with the aortic arch curvature and root dilation. Differences between controls and patients were evaluated using Mann-Whitney U test, and the relationship with the curvature was accessed by unpaired t-test. For statistical significance, we consider a P-value of 0.05. The aortic arch curvature was significantly different between patients 46.238 +/- 5.581 m(-1) and controls 41.066 +/- 5.323 m(-1). Haemodynamic parameters as wall shear stress circumferential (WSS-C), and eccentricity (ECC), were significantly different between TGA patients and controls in both the root and ascending aorta regions. The distribution of forces along the ascending aorta is highly inhomogeneous in TGA patients. We found that the backward velocity (B-VEL), WSS-C, velocity angle (VEL-A), regurgitation fraction (RF), and ECC are highly correlated with the aortic arch curvature and root dilatation. Conclusion We have identified six potential biomarkers (B-VEL, WSS-C, VEL-A, RF, and ECC), which may be helpful for follow-up evaluation and early prediction of aortic root dilatation in this patient population.
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    Impact of Respiratory Gating on Hemodynamic Parameters from 4D Flow MRI
    (2022) Denecken, Esteban ; Sotelo, Julio ; Arrieta, Cristobal ; Andia, Marcelo E. ; Uribe, Sergio
    The hemodynamic parameters from 4D flow datasets have shown promising diagnostic value in different cardiovascular pathologies. However, the behavior of these parameters can be affected when the 4D flow data are corrupted by respiratory motion. The purpose of this work was to perform a quantitative comparison between hemodynamic parameters computed from 4D flow cardiac MRI both with and without respiratory self-gating. We considered 4D flow MRI data from 15 healthy volunteers (10 men and 5 women, 30.40 +/- 6.23 years of age) that were acquired at 3T. Using a semiautomatic segmentation process of the aorta, we obtained the hemodynamic parameters from the 4D flow MRI, with and without respiratory self-gating. A statistical analysis, using the Wilcoxon signed-rank test and Bland-Altman, was performed to compare the hemodynamic parameters from both acquisitions. We found that the calculations of the hemodynamic parameters from 4D flow data that were acquired without respiratory self-gating showed underestimated values in the aortic arch, and the descending and diaphragmatic aorta. We also found a significant variability of the hemodynamic parameters in the ascending aorta of healthy volunteers when comparing both methods. The 4D flow MRI requires respiratory compensation to provide reliable calculations of hemodynamic parameters.
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    Mechanics-informed snakes isogeometric analysis (MISIGA): an image-based method for the estimation of local deformation and strain in blood vessels
    (2022) Cox, Agustin; Ortiz-Puerta, David; Sotelo, Julio; Uribe, Sergio; Hurtado, Daniel E.
    Abnormal deformation of blood vessels has been related to the onset and progression of prevalent cardiovascular diseases. This mechanical connection has motivated the development of computational techniques to assess strain fields in the wall of the aorta from medical images. In this work, we present the mechanics-informed snakes isogeometric analysis (MISIGA) method, which provides seamless 3D estimations of strain fields in the full aorta from magnetic resonance images. Our approach leverages image segmentation formulations with advanced curvilinear representations of irregular vessels to capture the deformation mapping between two configurations captured by image datasets. We further inform this model by describing the motion of the aortic wall based on a Kirchhoff-Love shell approach, which allows us to construct continuous circumferential and longitudinal strain fields in the full aorta. We validate the MISIGA method using synthetically generated images from aortic mechanical simulations, obtaining errors in the strain estimation of 13.2 and 9.8 for the circumferential and longitudinal components. This performance compares favorably with other approaches that are not informed by mechanical considerations. Further, we apply the MISIGA method in the strain assessment of the aorta of a normal subject, which results in longitudinal and circumferential strain values that are in the range of those found in previous studies. We envision that the MISIGA method can open the way to seamless 3D high-fidelity analysis of local strain from medical images of the aorta and other vessels.
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    Non-invasive local pulse wave velocity using 4D-flow MRI
    (2022) Mura, Joaquin; Sotelo, Julio; Mella, Hernan; Wong, James; Hussain, Tarique; Ruijsink, Bram; Uribe, Sergio
    Pulse Wave Velocity (PWV) corresponds to the velocity at which pressu r e waves, generated by the systolic contraction in the heart, propagate along the arterial tree. Due to the comple x interplay between blood flow and the artery wall, PWV is related to inherent mechanical properties and arterial morphology. PWV has been widely accepted as a biomarker and early predictor to evaluate global arterial distensibility. Sti l l , several local abnor-malities often remain hidden or difficult to detect using non-invasive techniques. Here, we introduce a novel method to efficiently construct a local estimate of PWV along the aorta using 4D-Flow MRI data. A geodesic distance map was used to track advancing pulses for efficient flow calculations, based on the observation that the propagation of velocity wavefronts strongly depends on the arterial morphology. This procedure allows us a robust evaluation of the local transit time due to the pulse wave at each position in the aorta. Moreover, the estimation of the local PWV map did not require centerlines, and the final result is projected back to 3D using the same geodesic map. We evaluated PWV values in healthy young and adult volunteers and patients with uni-ventricular physiology after a Fontan procedure. Ou r method is fast, semi-automatic, and depicts differences between young versus adult volunteers and young volunteers versus Fontan patients, showing consistent results compared to global methods. Remarkably, the technique could detect local differences of PWV on the aortic arch for al l subjects, being consistent with previous findings of reduced PWV in the aortic arch.
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    Three-dimensional quantification of circulation using finite-element methods in four-dimensional flow MR data of the thoracic aorta
    (2022) Sotelo, Julio; Bissell, Malenka M.; Jiang, Yaxin; Mella, Hernan; Mura, Joaquin; Uribe, Sergio
    Purpose Three-dimensional (3D) quantification of circulation using a Finite Elements methodology. Methods We validate our 3D method using an in-silico arch model, for different mesh resolutions, image resolution and noise levels, and we compared this with a currently used 2D method. Finally, we evaluated the application of our methodology in 4D Flow MRI data of ascending aorta of six healthy volunteers, and six bicuspid aortic valve (BAV) patients, three with right and three with left handed flow, at peak systole. The in-vivo data was compared using a Mann-Whitney U-test between volunteers and patients (right and left handed flow). Results The robustness of our method throughout different image resolutions and noise levels showed subestimation of circulation less than 45 cm(2)/s in comparison with the 55cm(2)/s generated by the current 2D method. The circulation (mean +/- SD) of the healthy volunteer group was 13.83 +/- 28.78 cm(2)/s, in BAV patients with right-handed flow 724.37 +/- 317.53 cm(2)/s, and BAV patients with left-handed flow -480.99 +/- 387.29 cm(2)/s. There were significant differences between healthy volunteers and BAV patients groups (P-value < .01), and also between BAV patients with a right-handed or left-handed helical flow and healthy volunteers (P-value < .01). Conclusion We propose a novel 3D formulation to estimate the circulation in the thoracic aorta, which can be used to assess the differences between normal and diseased hemodynamic from 4D-Flow MRI data. This method also can correctly differentiate between the visually seen right- and left-handed helical flow, which suggests that this approach may have high clinical sensitivity, but requires confirmation in longitudinal studies with a large cohort.
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    Tissue engineered in-vitro vascular patch fabrication using hybrid 3D printing and electrospinning
    (2022) Mayoral, Isabel; Bevilacqua, Elisa; Gomez, Gorka; Hmadcha, Abdelkrim; Gonzalez-Loscertales, Ignacio; Reina, Esther; Sotelo, Julio; Dominguez, Antonia; Perez-Alcantara, Pedro; Smani, Younes; Gonzalez-Puertas, Patricia; Mendez, Ana; Uribe, Sergio; Smani, Tarik; Ordonez, Antonio; Valverde, Israel
    Three-dimensional (3D) engineered cardiovascular tissues have shown great promise to replace damaged structures. Specifically, tissue engineering vascular grafts (TEVG) have the potential to replace biological and synthetic grafts. We aimed to design an in-vitro patient-specific patch based on a hybrid 3D print combined with vascular smooth muscle cells (VSMC) differentiation. Based on the medical images of a 2 months-old girl with aortic arch hypoplasia and using computational modelling, we evaluated the most hemodynamically efficient aortic patch surgical repair. Using the designed 3D patch geometry, the scaffold was printed using a hybrid fused deposition modelling (FDM) and electrospinning techniques. The scaffold was seeded with multipotent mesenchymal stem cells (MSC) for later maturation to derived VSMC (dVSMC). The graft showed adequate resistance to physiological aortic pressure (burst pressure 101 +/- 15 mmHg) and a porosity gradient ranging from 80 to 10 mu m allowing cells to infiltrate through the entire thickness of the patch. The bio-scaffolds showed good cell viability at days 4 and 12 and adequate functional vasoactive response to endothelin-1. In summary, we have shown that our method of generating patient-specific patch shows adequate hemodynamic profile, mechanical properties, dVSMC infiltration, viability and functionality. This innovative 3D biotechnology has the potential for broad application in regenerative medicine and potentially in heart disease prevention.
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    Validation of 4D Flow based relative pressure maps in aortic flows
    (2021) Nolte, David; Urbina, Jesus; Sotelo, Julio; Sok, Leo; Montalba, Cristian; Valverde, Israel; Osses, Axel; Uribe, Sergio; Bertoglio, Cristobal
    While the clinical gold standard for pressure difference measurements is invasive catheterization, 4D Flow MRI is a promising tool for enabling a non-invasive quantification, by linking highly spatially resolved velocity measurements with pressure differences via the incompressible Navier-Stokes equations. In this work we provide a validation and comparison with phantom and clinical patient data of pressure difference maps estimators. We compare the classical Pressure Poisson Estimator (PPE) and the new Stokes Estimator (STE) against catheter pressure measurements under a variety of stenosis severities and flow intensities. Specifically, we use several 4D Flow data sets of realistic aortic phantoms with different anatomic and hemodynamic severities and two patients with aortic coarctation. The phantom data sets are enriched by subsampling to lower resolutions, modification of the segmentation and addition of synthetic noise, in order to study the sensitivity of the pressure difference estimators to these factors. Overall, the STE method yields more accurate results than the PPE method compared to catheterization data. The superiority of the STE becomes more evident at increasing Reynolds numbers with a better capacity of capturing pressure gradients in strongly convective flow regimes. The results indicate an improved robustness of the STE method with respect to variation in lumen segmentation. However, with heuristic removal of the wall-voxels, the PPE can reach a comparable accuracy for lower Reynolds' numbers. (c) 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )