Publications by authors named "Gencer U"

Article Synopsis
  • * A total of 88 BAV patients underwent 4D flow and echocardiography, showing moderate changes in flow and the best correlation for flow measurements at the aortic annulus.
  • * While 4D flow MRI was more accurate for measuring forward volume than echocardiography, the agreement in grading aortic regurgitation between the two methods was found to be poor.
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Background: Coupling between left ventricle (LV) and left atrium (LA) plays a central role in the process of cardiac remodeling during aging and development of cardiac disease. The hydraulic force (HyF) is related to variation in size between LV and LA. The objectives of this study were to: (1) derive an estimate of left atrioventricular HyF using cine- Magnetic Resonance Imaging (MRI) in healthy subjects with a wide age range, and (2) study its relationship with age and conventional diastolic function parameters, as estimated by reference echocardiography.

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Purpose To investigate whether the peak early filling rate normalized to the filling volume (PEFR/FV) estimated from four-dimensional (4D) flow cardiac MRI may be used to assess impaired left ventricular (LV) filling and predict clinical outcomes in individuals with hypertrophic cardiomyopathy (HCM). Materials and Methods Cardiac MRI with a 4D flow sequence and late gadolinium enhancement (LGE), as well as echocardiography, was performed in 88 individuals: 44 participants with HCM from a French prospective registry (ClinicalTrials.gov; NCT01091480) and 44 healthy volunteers matched for age and sex.

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Background: Functional abnormalities of the ascending aorta (AA) have been mainly reported in young patients who underwent arterial switch operation (ASO) for transposition of the great arteries (TGA).

Objectives: To compare systolic, diastolic brachial and central blood pressures (bSBP, bDBP, cSBP, cDBP), aortic biomechanical parameters, and left ventricular (LV) afterload criteria in adult ASO patients with healthy controls and to assess their relationships with LV remodeling and aortic size.

Materials And Methods: Forty-one prospectively enrolled patients (16.

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Background: Ascending thoracic aortic aneurysm (ATAA) is a silent and threatening dilation of the ascending aorta (AscAo). Maximal aortic diameter which is currently used for ATAA patients management and surgery planning has been shown to inadequately characterize risk of dissection in a large proportion of patients. Our aim was to propose a comprehensive quantitative evaluation of aortic morphology and pressure-flow-wall associations from four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) data in healthy aging and in patients with ATAA.

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Article Synopsis
  • - The study aims to create a deep learning-based automated method for detecting aortic landmarks and lumen in 3D MRI scans, which can lead to more efficient and consistent evaluations of aortic diseases.
  • - A total of 391 participants, including healthy individuals and patients with various aortic conditions, were involved, and their data was split into training, validation, and testing groups for the deep learning model.
  • - Various statistical measures were employed to evaluate the performance of the deep learning model against traditional methods, focusing on segmentation accuracy and landmark detection to ensure robust results in assessing aortic morphology.
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Purpose: Abdominal aorta calcium (AAC) burden and dilatation are associated with an increased risk of mortality. The purpose of this study was to investigate determinants of AAC and abdominal aorta size in patients with essential hypertension.

Materials And Methods: Patients with uncomplicated essential hypertension who had undergone non-enhanced abdominal CT to rule out secondary hypertension in addition to biological test were recruited between 2010 and 2018.

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Article Synopsis
  • * Research conducted on female rodents showed that a single stress event can lead to lasting heart damage, as indicated by changes in blood biomarkers and various imaging techniques.
  • * The study highlights that long-term metabolic disruptions in the heart contribute to permanent damage, challenging the idea of Takotsubo being easily reversible and emphasizing the need for early treatment strategies.
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Background And Objective: Aortic stiffness can be evaluated by aortic distensibility or pulse wave velocity (PWV) using applanation tonometry, 2D phase contrast (PC) MRI and the emerging 4D flow MRI. However, such MRI tools may reach their technical limitations in populations with cardiovascular disease. Accordingly, this work focuses on the diagnostic value of aortic stiffness evaluated either by applanation tonometry or MRI in high-risk coronary artery disease (CAD) patients.

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Purpose: The purpose of this study was to investigate the benefit of aortic volumes compared to diameters or cross-sectional areas on three-dimensional (3D) magnetic resonance imaging (MRI) in discriminating between patients with dilated aorta and matched controls.

Materials And Methods: Sixty-two patients (47 men and 15 women; median age, 66 years; age range: 33-86 years) with tricuspid aortic valve and ascending thoracic aorta aneurysm (TAV-ATAA) and 43 patients (35 men and 8 women; median age, 51 years; age range: 17-76 years) with bicuspid aortic valve and dilated ascending aorta (BAV) were studied. One group of 54 controls matched for age and sex to patients with TAV-ATAA (39 men and 15 women; median age, 68 years; age range: 33-81 years) and one group of 42 controls matched for age and sex to patients with BAV (34 men and 8 women; median age, 50 years; age range: 17-77 years) were identified.

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Introduction And Objectives: Magnetic resonance imaging (MRI) including 4D flow is used before percutaneous pulmonary valve implantation (PPVI). As PPVI is limited by the size of the right ventricular outflow tract (RVOT), accurate sizing is needed to plan the intervention. The aim of this study was to compare different MRI modalities and invasive angiography to balloon sizing of RVOT.

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Objectives: Pulmonary regurgitation (PR) is common in adult congenital heart disease (ACHD). 2D phase contrast MRI is the reference method for the quantification of PR and helps in the decision of pulmonary valve replacement (PVR). 4D flow MRI can be an alternative method to estimate PR but more validation is still needed.

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Background: The long-term cardiovascular consequences of microgravity on large arteries are a threat for long-term space missions. We hypothesized that changes in arterial properties differ according to the arterial territory (upper or lower body), and arterial structure (elastic vs. muscular arteries), in response to 60-day head-down bed rest (HDBR).

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Background: In the case of breast cancer (BC), radiotherapy (RT) helps reduce locoregional recurrence and BC-related deaths but can lead to cardiotoxicity, resulting in an increased risk of long-term major cardiovascular events. It is therefore of primary importance to early detect subclinical left ventricular (LV) dysfunction in BC patients after RT and to determine the dose-response relationships between cardiac doses and these events.

Methods: Within the frame of the MEDIRAD European project (2017-2022), the prospective multicenter EARLY-HEART study (ClinicalTrials.

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Purpose: The purpose of this study was to investigate the value of 4D flow MRI for mitral filling measurements, using transthoracic echocardiography (TTE) and 2D flow MRI as references, as well as identify relationships with age and left ventricle (LV) remodeling in healthy volunteers.

Material And Methods: Fifty healthy volunteers (22 men, 28 women; mean age, 51.3 ± 16.

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Purpose: The 2020 edition of these Data Challenges was organized by the French Society of Radiology (SFR), from September 28 to September 30, 2020. The goals were to propose innovative artificial intelligence solutions for the current relevant problems in radiology and to build a large database of multimodal medical images of ultrasound and computed tomography (CT) on these subjects from several French radiology centers.

Materials And Methods: This year the attempt was to create data challenge objectives in line with the clinical routine of radiologists, with less preprocessing of data and annotation, leaving a large part of the preprocessing task to the participating teams.

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Article Synopsis
  • The study aimed to create an algorithm using convolutional neural networks (CNN) that can automatically estimate coronary artery calcium (CAC) from unenhanced ECG-gated CT scans.
  • Researchers trained a CNN with a 3D U-Net architecture on 783 CT scans to detect and segment calcifications, calculating the Agatston score and comparing it to radiologist assessments.
  • The final model achieved a high accuracy (C-index of 0.951), although it struggled with small or low-density calcifications near the mitral valve, potentially enhancing workflow by automating the CAC scoring process.
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In cardiovascular magnetic resonance, the 3D time-resolved phase-contrast technique, also known as 4D flow, is gaining increasing attention due to applications that exploit three-directional velocity encoding throughout the cardiac cycle. Blood flow volume assessment usually requires an expert to draw regions of interest (ROI) around the vessel cross section, whereas the errors involved in this estimation have not been thoroughly investigated. Our objective is to quantify the influence of ROI sizing, angulation and spatial resolution of the reconstructed plane employed in blood flow measurements using 4D flow.

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Automated segmentation of three-dimensional (3D) aortic magnetic resonance imaging (MRI) renders a possible retrospective selection of any location to perform quantification of aortic caliber perpendicular to its centerline and provides regional and global 3D biomarkers such as length, diameter, or volume. However, normative age-related values of such measures are still lacking. The aim of this study was to provide normal values for 3D aortic morphological measures and investigate their changes in aging and hypertension.

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Background: We aimed to provide a comprehensive aortic stiffness description using magnetic resonance imaging (MRI) in patients with ascending thoracic aorta aneurysm and tricuspid (TAV-ATAA) or bicuspid (BAV) aortic valve.

Methods: This case-control study included 18 TAV-ATAA and 19 BAV patients, with no aortic valve stenosis/severe regurgitation, who were 1:1 age-, gender- and central blood pressures (BP)-matched to healthy volunteers. Each underwent simultaneous aortic MRI and BP measurements.

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Article Synopsis
  • Arterial pulse wave velocity (PWV) is linked to higher mortality rates in older adults and those with diseases, prompting the evaluation of various methods for estimating aortic PWV using advanced imaging techniques like 4D flow CMR and traditional methods like Cf-PWV and BH-PWV.
  • In a study involving 47 healthy participants, several approaches for calculating aortic PWV through 4D flow CMR were tested, focusing on the accuracy and reproducibility of different estimation techniques such as using velocity curves from only two locations (ascending and descending aorta) versus using all curves along the aortic centerline.
  • Results indicated significant correlations between 4D flow CMR aoPWV estimates and traditional PWV measures
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Objectives: Pulse wave velocity (PWV) of the aortic arch is usually estimated by using 2D phase contrast in MRI. Thanks to 4D flow MRI, segmental PWV of the ascending and descending aorta, as well as PWV of the entire thoracic aorta can now be estimated within the same examination. Our objective is to compare PWVs obtained by 2D and 4D PC, through their relationships with carotid-femoral PWV (cf-PWV), age and left ventricular remodelling.

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Objective: To evaluate an automatic correction method for velocity offset errors in cardiac 4D-flow acquisitions.

Materials And Methods: Velocity offset correction was done in a plane-by-plane scheme and compared to a volumetric approach. Stationary regions were automatically detected.

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Background: Aging-related arterial stiffness is associated with substantial changes in global and local arterial pressures. The subsequent early return of reflected pressure waves leads to an elevated left ventricular (LV) afterload and ultimately to a deleterious concentric LV remodeling.

Purpose: To compute aortic time-resolved pressure fields of healthy subjects from 4D flow MRI and to define relevant pressure-based markers while investigating their relationship with age, LV remodeling, as well as tonometric augmentation index (AIx) and pulse wave velocity (PWV).

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