3D Vortex-Energetics in the Left Pulmonary Artery for Differentiating Pulmonary Arterial Hypertension and Pulmonary Venous Hypertension Groups Using 4D Flow MRI.

Background: Pulmonary hypertension (PH) is a life-threatening. Differentiation pulmonary arterial hypertension (PAH) from pulmonary venous hypertension (PVH) is important due to distinct treatment protocols. Invasive right heart catheterization (RHC) remains the reference standard but noninvasive alternatives are needed.

Emerging multimodality imaging techniques for the pulmonary circulation.

Pulmonary hypertension (PH) remains a challenging condition to diagnose, classify and treat. Current approaches to the assessment of PH include echocardiography, ventilation/perfusion scintigraphy, cross-sectional imaging using computed tomography and magnetic resonance imaging, and right heart catheterisation. However, these approaches only provide an indirect readout of the primary pathology of the disease: abnormal vascular remodelling in the pulmonary circulation.

Valvular and ascending aortic hemodynamics of the On-X aortic valved conduit by same-day echocardiography and 4D flow MRI.

This study aims to assess whether the On-X aortic valved conduit better restores normal valvular and ascending aortic hemodynamics than other commonly used bileaflet mechanical valved conduit prostheses from St. Jude Medical and Carbomedics by using same-day transthoracic echocardiography (TTE) and 4D flow magnetic resonance imaging (MRI) examinations. TTE and 4D flow MRI were performed back-to-back in 10 patients with On-X, six patients with St.

MRI Quantification of Left Atrial Circumferential Strain in Mitral Regurgitation: A Feasibility and Reproducibility Study.

Background: MRI-derived left atrial (LA) longitudinal strain has been shown to be a marker for mitral regurgitation, but the utility of LA circumferential strain remains unclear.

Purpose: To assess feasibility and reproducibility of LA circumferential strain, identify changes in mitral regurgitation patients compared to healthy volunteers, and determine strain's association with mitral regurgitation severity and cardiac function.

Study Type: Retrospective.

Left ventricular four-dimensional blood flow distribution, energetics, and vorticity in chronic myocardial infarction patients with/without left ventricular thrombus.

Background: Left ventricular thrombus (LVT) formation is a frequent and serious complication of myocardial infarction (MI). How global LV flow characteristics are related to this phenomenon is yet uncertain. In this study, we investigated LV flow differences using 4D flow cardiovascular magnetic resonance (CMR) between chronic MI patients with LVT [MI-LVT(+)] and without LVT [MI-LVT(-)], and healthy controls.

Aortic Pulse Wave Velocity Evaluated by 4D Flow MRI Across the Adult Lifespan.

Background: Evaluation of aortic stiffness by pulse wave velocity (PWV) across the adult lifespan is needed to better understand normal aging in women and men.

Purpose: To characterize PWV in the thoracic aorta using 4D flow MRI in an age- and sex-stratified cohort of healthy adults.

Study Type: Retrospective.

Direct mitral regurgitation quantification in hypertrophic cardiomyopathy using 4D flow CMR jet tracking: evaluation in comparison to conventional CMR.

Background: Quantitative evaluation of mitral regurgitation (MR) in hypertrophic cardiomyopathy (HCM) by cardiovascular magnetic resonance (CMR) relies on an indirect volumetric calculation. The aim of this study was to directly assess and quantify MR jets in patients with HCM using 4D flow CMR jet tracking in comparison to standard-of-care CMR indirect volumetric method.

Methods: This retrospective study included patients with HCM undergoing 4D flow CMR.

Hemodynamic interplay of vorticity, viscous energy loss, and kinetic energy from 4D Flow MRI and link to cardiac function in healthy subjects and Fontan patients.

The purpose of this study was to directly assess (patho)physiology of intraventricular hemodynamic interplay between four-dimensional flow cardiovascular magnetic resonance imaging (4D Flow MRI)-derived vorticity with kinetic energy (KE) and viscous energy loss (EL) over the cardiac cycle and their association to ejection fraction (EF) and stroke volume (SV). Fifteen healthy subjects and thirty Fontan patients underwent whole heart 4D Flow MRI. Ventricular vorticity, KE, and EL were computed over systole (vorticity_vol, KE, and EL) and diastole (vorticity_vol, KE, and EL).

4D flow MRI left atrial kinetic energy in hypertrophic cardiomyopathy is associated with mitral regurgitation and left ventricular outflow tract obstruction.

To noninvasively assess left atrial (LA) kinetic energy (KE) in hypertrophic cardiomyopathy (HCM) patients using 4D flow MRI and evaluate coupling associations with mitral regurgitation (MR) and left ventricular outflow tract (LVOT) obstruction. Twenty-nine retrospectively identified patients with HCM underwent 4D flow MRI. MRI-estimated peak LVOT pressure gradient (∆P) was used to classify patients into non-obstructive and obstructive HCM.

Intracardiac and Vascular Hemodynamics with Cardiovascular Magnetic Resonance in Heart Failure.

In heart failure (HF), the impaired heart loses its ability to competently eject blood during systole or fill with blood during diastole, manifesting in multifaceted abnormal intracardiac or intravascular flow dynamics. Conventional imaging techniques are limited in their ability to evaluate multidirectional multidimensional flow alterations in HF. Four-dimensional (4-D) flow magnetic resonance imaging (MRI) has emerged as a promising technique to comprehensively visualize and quantify changes in 3-dimensional blood flow dynamics in complex cardiovascular diseases.

Four-dimensional Virtual Catheter: Noninvasive Assessment of Intra-aortic Hemodynamics in Bicuspid Aortic Valve Disease.

Background Four-dimensional (4D) flow MRI enables the evaluation of blood flow alterations in patients with congenital bicuspid aortic valve (BAV). However, current analysis methods are cumbersome and lack the use of the volumetric data from 4D MRI. Purpose To investigate the feasibility and reproducibility of a technique that uses a catheter-like mathematical model (virtual catheter) to assess volumetric intra-aortic hemodynamics from 4D flow MRI in patients with BAV.

Stress increases intracardiac 4D flow cardiovascular magnetic resonance -derived energetics and vorticity and relates to VOmax in Fontan patients.

Background: We hypothesize that dobutamine-induced stress impacts intracardiac hemodynamic parameters and that this may be linked to decreased exercise capacity in Fontan patients. Therefore, the purpose of this study was to assess the effect of pharmacologic stress on intraventricular kinetic energy (KE), viscous energy loss (EL) and vorticity from four-dimensional (4D) Flow cardiovascular magnetic resonance (CMR) imaging in Fontan patients and to study the association between stress response and exercise capacity.

Methods: Ten Fontan patients underwent whole-heart 4D flow CMR before and during 7.

Intracardiac 4D Flow MRI in Congenital Heart Disease: Recommendations on Behalf of the ISMRM Flow & Motion Study Group.

5 Technical Efficacy: Stage 5 J. Magn. Reson.

Clinical assessment of aortic valve stenosis: Comparison between 4D flow MRI and transthoracic echocardiography.

Background: The prevalence of valvular aortic stenosis (AS) increases as the population ages. Echocardiographic measurements of peak jet velocity (V ), mean pressure gradient (P ), and aortic valve area (AVA) determine AS severity and play a pivotal role in the stratification towards valvular replacement. A multimodality imaging approach might be needed in cases of uncertainty about the actual severity of the stenosis.

Four-dimensional flow magnetic resonance imaging-derived blood flow energetics of the inferior vena cava-to-extracardiac conduit junction in Fontan patients.

Objectives: In patients with the Fontan circulation, systemic venous return flows passively towards the lungs. Because of the absence of the subpulmonary ventricle, favourable blood flow patterns with minimal energy loss are clinically relevant. The region where the inferior vena cava, the hepatic veins and the extracardiac conduit join (IVC-conduit junction) is a potential source of increased energy loss.

Left ventricular blood flow kinetic energy after myocardial infarction - insights from 4D flow cardiovascular magnetic resonance.

Background: Myocardial infarction (MI) leads to complex changes in left ventricular (LV) haemodynamics that are linked to clinical outcomes. We hypothesize that LV blood flow kinetic energy (KE) is altered in MI and is associated with LV function and infarct characteristics. This study aimed to investigate the intra-cavity LV blood flow KE in controls and MI patients, using cardiovascular magnetic resonance (CMR) four-dimensional (4D) flow assessment.

Left ventricular thrombus formation in myocardial infarction is associated with altered left ventricular blood flow energetics.

Aims: The main aim of this study was to characterize changes in the left ventricular (LV) blood flow kinetic energy (KE) using four-dimensional (4D) flow cardiovascular magnetic resonance imaging (CMR) in patients with myocardial infarction (MI) with/without LV thrombus (LVT).

Methods And Results: This is a prospective cohort study of 108 subjects [controls = 40, MI patients without LVT (LVT- = 36), and MI patients with LVT (LVT+ = 32)]. All underwent CMR including whole-heart 4D flow.

Disproportionate intraventricular viscous energy loss in Fontan patients: analysis by 4D flow MRI.

Aims: To non-invasively assess intraventricular viscous energy loss (EL) and proportionality to kinetic energy (KE) in Fontan patients using 4D flow magnetic resonance imaging (MRI) and compare to healthy controls.

Methods And Results: Thirty Fontan patients and 15 controls underwent 4D flow MRI. Ventricular EL was computed and normalized by end-diastolic volume (EDV).

Scan-rescan reproducibility of diastolic left ventricular kinetic energy, viscous energy loss and vorticity assessment using 4D flow MRI: analysis in healthy subjects.

The aim of the current study was to assess the scan-rescan reproducibility of left ventricular (LV) kinetic energy (KE), viscous energy loss (EL) and vorticity during diastole from four-dimensional flow magnetic resonance imaging (4D flow MRI) in healthy subjects. Twelve volunteers (age 27 ± 3 years) underwent whole-heart 4D flow MRI twice in one session. In-scan consistency was evaluated by correlation between KE and EL.

Clinical applications of intra-cardiac four-dimensional flow cardiovascular magnetic resonance: A systematic review.

Background: Four-dimensional flow cardiovascular magnetic resonance (4D flow CMR) is an emerging non-invasive imaging technology used to visualise and quantify intra-cardiac blood flow. The aim of this systematic review is to assess the literature on the current clinical applications of intra-cardiac 4D flow CMR.

Methods: A systematic review was conducted to evaluate the literature on the intra-cardiac clinical applications of 4D flow CMR.

In-scan and scan-rescan assessment of LV in- and outflow volumes by 4D flow MRI versus 2D planimetry.

Purpose: To evaluate the in-scan and scan-rescan consistency of left ventricular (LV) in- and outflow assessment from 1) 2D planimetry; 2) 4D flow magnetic resonance imaging (MRI) with retrospective valve tracking, and 3) 4D flow MRI with particle tracing.

Materials And Methods: Ten healthy volunteers (age 27 ± 3 years) underwent multislice cine short-axis planimetry and whole-heart 4D flow MRI on a 3T MRI scanner twice with repositioning between the scans. LV in- and outflow was compared from 1) 2D planimetry; 2) 4D flow MRI with retrospective valve tracking over the mitral valve (MV) and aortic valve (AV), and 3) 4D flow MRI with particle tracing through forward and backward integration of velocity data.

Comparison of fast acquisition strategies in whole-heart four-dimensional flow cardiac MR: Two-center, 1.5 Tesla, phantom and in vivo validation study.

Purpose: To validate three widely-used acceleration methods in four-dimensional (4D) flow cardiac MR; segmented 4D-spoiled-gradient-echo (4D-SPGR), 4D-echo-planar-imaging (4D-EPI), and 4D-k-t Broad-use Linear Acquisition Speed-up Technique (4D-k-t BLAST).

Materials And Methods: Acceleration methods were investigated in static/pulsatile phantoms and 25 volunteers on 1.5 Tesla MR systems.

Unravelling cardiovascular disease using four dimensional flow cardiovascular magnetic resonance.

Knowledge of normal and abnormal flow patterns in the human cardiovascular system increases our understanding of normal physiology and may help unravel the complex pathophysiological mechanisms leading to cardiovascular disease. Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) has emerged as a suitable technique that enables visualization of in vivo blood flow patterns and quantification of parameters that could potentially be of prognostic value in the disease process. In this review, current image processing tools that are used for comprehensive visualization and quantification of blood flow and energy distribution in the heart and great vessels will be discussed.