ANALYSES OF INTRA-LEFT VENTRICULAR (LV) FLOW DYNAMICS IN PATIENTS WITH NORMAL AND IMPAIRED LV FUNCTION USING PHASE-RESOLVED 3D CINE PHASE-CONTRAST MRI (4D-FLOW MRI)

Objective. To assess phase-contrast MRI in the evaluation of left ventricular hemodynamics changes in various forms of hypertrophic cardiomyopathy.Materials and methods. 11 patients were examined: without pathology of the cardiovascular system (n = 3), with apical (n = 3), diffuse-septal (n = 2) and focal-basal (n = 3) types of hypertrophic cardiomyopathy. All patients underwent MRI of the heart with an additional phase-contrast sequence of the left ventricular area. Postprocessing carried out in the 4D FLOW application (Siemens).Results. Data were obtained on the geometry and dynamics of vortex diastolic flows in the left ventricular of all patients. In patients with hypertrophic cardiomyopathy, an increase in the distance to the center of the vortex and a decrease in the normalized area and peak velocity of the vortex is determined. The diffuse-septal type is characterized by a minimal vortex peak velocity; apical type - by the maximum vortex sphericity index. For patients with a focalbasal type of hypertrophic cardiomyopathy the maximum changes in blood flow are determined in late diastole (absence of vortexes).Conclusion. 4D FLOW Phase-contrast MRI allows identifying and assessing LV vortical flow. Quantitative analysis can be used to characterize the remodeling of LV blood flow of various types of hypertrophic cardiomyopathy.

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P585Intra left ventricular hemodynamics assessed using 4D flow MRI in the patient with left ventricular thrombus

European Heart Journal ◽

10.1093/eurheartj/ehz747.0194 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

T Sakakibara ◽

K Suwa ◽

Y Kaneko ◽

K Akita ◽

R Sato ◽

...

Keyword(s):

Diagnostic Accuracy ◽

Flow Velocity ◽

Left Ventricular ◽

Area Ratio ◽

Lv Function ◽

4D Flow Mri ◽

4D Flow ◽

Lower Flow ◽

Vortex Size ◽

Flow Mri

Abstract Background Early detection of left ventricular mural thrombus (LVT) in patients with reduced ejection fraction (EF) is crucial in prevention of arterial embolism. 3D-cine phase-contrast magnetic resonance imaging (4D flow MRI) can visualize the intra-LV vortex flow in diastole and quantify the maximum flow velocity (Vmax) at the apex. it remains, however, unknown whether 4D flow MRI is useful for detecting LVT. Purpose The purpose of our study is to examine the intra-LV vortex formation and flow velocity in patients with severe LV dysfunction using 4D Flow MRI, and to compare differences in intra-LV flow dynamics between patients with and without LVT. We also examined the diagnostic accuracy to detect LVT by 4D flow MRI. Methods Twenty-nine patients with impaired LV function (LVEF 25.8±7.4%, 62.5±12.3 years old, 24 males, 11 with ischemic cardiomyopathy, 9 with LVT) underwent 4D flow MRI from January 2012 to August 2018 in our institution. Intra-LV vortex size was evaluated as vortex/LV area ratio by streamline imaging (Figure 1). The diagnostic accuracy to predict LVT by vortex size and Vmax at the apex was determined by ROC analysis. Results The vortex was smaller (vortex/LV area ratio; 30.6±7.0% vs. 45.1±9.0%, p<0.05) and Vmax at the apex was lower (0.20±0.04 m/s vs. 0.28±0.09 m/s, p=0.013) in patients with LVT compared to those without LVT. The AUC was 0.789 for Vmax (cut-off value=0.226 m/s, sensitivity=0.889, specificity=0.650) and was 0.900 for vortex/LV area ratio (cut-off value=34.7%, sensitivity=0.889, specificity=0.850). Figure 1 Conclusion The smaller size of intra-LV vortex and the lower flow velocity at the LV apex may have association with LVT formation in patients with reduced EF. 4D flow MRI might be useful to predict LVT formation. Large scale longitudinal study is warranted to evaluate the incidence of LVT in the patients with lower flow velocity. Acknowledgement/Funding None

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Time‐resolved 3D cine phase‐contrast magnetic resonance imaging (4D‐flow MRI) can quantitatively assess portosystemic shunt severity and confirm normalization of portal flow after embolization of large portosystemic shunts

Hepatology Research ◽

10.1111/hepr.13616 ◽

2021 ◽

Author(s):

Ryota Hyodo ◽

Yasuo Takehara ◽

Takashi Mizuno ◽

Kazushige Ichikawa ◽

Yoji Ishizu ◽

...

Keyword(s):

Phase Contrast ◽

Resonance Imaging ◽

4D Flow Mri ◽

Portal Flow ◽

4D Flow ◽

Time Resolved ◽

Portosystemic Shunts ◽

Contrast Magnetic Resonance ◽

Flow Mri ◽

Cine Phase Contrast

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Abstract 14534: In vitro Assessment of Transvalvular Peak Velocity Measurement for Various Orifice Shapes: Comparison Between 4D Flow MRI vs. Doppler Echocardiography

Circulation ◽

10.1161/circ.142.suppl_3.14534 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Jeesoo Lee ◽

Nadia El hangouche ◽

Liliana Ma ◽

Michael Scott ◽

Michael Markl ◽

...

Keyword(s):

Temporal Resolution ◽

Continuous Wave ◽

Peak Velocity ◽

Left Ventricular ◽

Patient Specific ◽

Maximal Velocity ◽

4D Flow Mri ◽

4D Flow ◽

Flow Phantom ◽

Flow Mri

Introduction: 4D flow MRI can assess transvalvular velocity, but validation against continuous wave (CW) Doppler echo is limited in high-velocity regurgitation and stenosis situations. We sought to compare 4D flow MRI and echo peak velocity using a pulsatile echo-MRI flow phantom. Materials and Methods: An MRI-compatible flow phantom with restrictive orifice situated was driven by a left ventricular assist device at 50 bpm (figure 1A). Three orifice shapes were tested: circular, elliptical and 3D-printed patient-specific mitral regurgitant orifice model of prolapse with areas of 0.5, 0.41 and 0.35 cm 2 , respectively. CW Doppler was acquired with peak velocity extracted from the profile. Retrospectively-gated 4D flow MRI was performed (spatial resolution = 2 mm isotropic, temporal resolution = 36 ms, encoding velocity = 400 cm/s). Maximal velocity magnitude was extracted volumetrically (figure 1B). An echo-mimicking profile was also obtained with a “virtual” ultrasound beam in the 4D flow data to simulate CW Doppler (figure 1C). Bland-Altman analysis was used to assess the agreement of temporal peak velocities. Results: 4D flow MRI demonstrated a centrally directed jet for the circular and elliptical orifices and an oblique jet for the prolapse orifice (figure 1B). Peak velocities were in excellent agreement between 4D flow MRI vs. echo for the circular (peak: 5.13 vs. 5.08 m/s, bias = 0.06 ± 0.66 m/s, figure 1D) and the elliptical orifice (peak: 4.95 vs. 4.79 m/s, bias = 0.07 ± 0.87 m/s, figure 1E). The prolapse orifice velocity was underestimated somewhat by MRI by ~10% (peak: 4.41 vs. 4.90 m/s, bias=0.26±1.18, figure 1F). Conclusion: 4D flow MRI can quantify high velocities like echo for simple geometries while underestimating for more complex geometry, likely due to partial volume effects. Further investigation is warranted to systematically investigate the effects of 4D flow MRI spatial and temporal resolution as well as the jet angle on velocity quantification accuracy.

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Time-resolved 3-dimensional magnetic resonance phase contrast imaging (4D Flow MRI) reveals altered blood flow patterns in the ascending aorta of patients with valve-sparing aortic root replacement

Journal of Thoracic and Cardiovascular Surgery ◽

10.1016/j.jtcvs.2019.02.127 ◽

2020 ◽

Vol 159 (3) ◽

pp. 798-810.e1 ◽

Cited By ~ 6

Author(s):

Thekla H. Oechtering ◽

Malte M. Sieren ◽

Peter Hunold ◽

Anja Hennemuth ◽

Markus Huellebrand ◽

...

Keyword(s):

Phase Contrast ◽

Phase Contrast Imaging ◽

4D Flow Mri ◽

Contrast Imaging ◽

4D Flow ◽

Time Resolved ◽

3 Dimensional ◽

Flow Mri ◽

Altered Blood ◽

Blood Flow Patterns

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Reduced regional flow in the left ventricle after anterior acute myocardial infarction: a case control study using 4D flow MRI

BMC Medical Imaging ◽

10.1186/s12880-019-0404-7 ◽

2019 ◽

Vol 19 (1) ◽

Cited By ~ 1

Author(s):

Philip A. Corrado ◽

Jacob A. Macdonald ◽

Christopher J. François ◽

Niti R. Aggarwal ◽

Jonathan W. Weinsaft ◽

...

Keyword(s):

Myocardial Infarction ◽

Acute Myocardial Infarction ◽

Linear Models ◽

Left Ventricular ◽

Short Axis ◽

Flow Data ◽

4D Flow Mri ◽

4D Flow ◽

Regional Flow ◽

Flow Mri

Abstract Background Acute myocardial infarction (AMI) alters left ventricular (LV) hemodynamics, resulting in decreased global LV ejection fraction and global LV kinetic energy. We hypothesize that anterior AMI effects localized alterations in LV flow and developed a regional approach to analyze these local changes with 4D flow MRI. Methods 4D flow cardiac magnetic resonance (CMR) data was compared between 12 anterior AMI patients (11 males; 66 ± 12yo; prospectively acquired in 2016–2017) and 19 healthy volunteers (10 males; 40 ± 16yo; retrospective from 2010 to 2011 study). The LV cavity was contoured on short axis cine steady-state free procession CMR and partitioned into three regions: base, mid-ventricle, and apex. 4D flow data was registered to the short axis segmentation. Peak systolic and diastolic through-plane flows were compared region-by-region between groups using linear models of flow with age, sex, and heart rate as covariates. Results Peak systolic flow was reduced in anterior AMI subjects compared to controls in the LV mid-ventricle (fitted reduction = 3.9 L/min; P = 0.01) and apex (fitted reduction = 1.4 L/min; P = 0.02). Peak diastolic flow was also lower in anterior AMI subjects compared to controls in the apex (fitted reduction = 2.4 L/min; P = 0.01). Conclusions A regional method to analyze 4D LV flow data was applied in anterior AMI patients and controls. Anterior AMI patients had reduced regional flow relative to controls.

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