scholarly journals Validation and reproducibility of cardiovascular 4D-flow MRI from two vendors using 2 × 2 parallel imaging acceleration in pulsatile flow phantom and in vivo with and without respiratory gating

2018 ◽  
Vol 60 (3) ◽  
pp. 327-337 ◽  
Author(s):  
Jelena Bock ◽  
Johannes Töger ◽  
Sebastian Bidhult ◽  
Karin Markenroth Bloch ◽  
Per Arvidsson ◽  
...  
Keyword(s):  
Respiratory Gating ◽  
Volume Flow ◽  
Acquisition Time ◽  
Cine Imaging ◽  
Clinical Use ◽  
4D Flow Mri ◽  
4D Flow ◽  
Accuracy And Precision ◽  
Flow Mri

Background 4D-flow magnetic resonance imaging (MRI) is increasingly used. Purpose To validate 4D-flow sequences in phantom and in vivo, comparing volume flow and kinetic energy (KE) head-to-head, with and without respiratory gating. Material and Methods Achieva dStream (Philips Healthcare) and MAGNETOM Aera (Siemens Healthcare) 1.5-T scanners were used. Phantom validation measured pulsatile, three-dimensional flow with 4D-flow MRI and laser particle imaging velocimetry (PIV) as reference standard. Ten healthy participants underwent three cardiac MRI examinations each, consisting of cine-imaging, 2D-flow (aorta, pulmonary artery), and 2 × 2 accelerated 4D-flow with (Resp+) and without (Resp−) respiratory gating. Examinations were acquired consecutively on both scanners and one examination repeated within two weeks. Volume flow in the great vessels was compared between 2D- and 4D-flow. KE were calculated for all time phases and voxels in the left ventricle. Results Phantom results showed high accuracy and precision for both scanners. In vivo, higher accuracy and precision ( P < 0.001) was found for volume flow for the Aera prototype with Resp+ (–3.7 ± 10.4 mL, r = 0.89) compared to the Achieva product sequence (–17.8 ± 18.6 mL, r = 0.56). 4D-flow Resp− on Aera had somewhat larger bias (–9.3 ± 9.6 mL, r = 0.90) compared to Resp+ ( P = 0.005). KE measurements showed larger differences between scanners on the same day compared to the same scanner at different days. Conclusion Sequence-specific in vivo validation of 4D-flow is needed before clinical use. 4D-flow with the Aera prototype sequence with a clinically acceptable acquisition time (<10 min) showed acceptable bias in healthy controls to be considered for clinical use. Intra-individual KE comparisons should use the same sequence.

scholarly journals In vivo validation of 4D flow MRI for assessing the hemodynamics of portal hypertension

2013 ◽  
Vol 37 (5) ◽  
pp. spcone-spcone
Author(s):  
Alejandro Roldán-Alzate ◽  
Alex Frydrychowicz ◽  
Eric Niespodzany ◽  
Ben R. Landgraf ◽  
Kevin M. Johnson ◽  
...  
Keyword(s):  
Portal Hypertension ◽  
4D Flow Mri ◽  
4D Flow ◽  
Flow Mri ◽  
In Vivo Validation

scholarly journals 1050: Cross-modality, in-vivo validation of 4D-Flow MRI evaluation of uterine artery blood flow in human pregnancy

2019 ◽  
Vol 220 (1) ◽  
pp. S673-S674
Author(s):  
Nadav Schwartz ◽  
Eileen Hwuang ◽  
Ana Rodriguez-Soto ◽  
Felix Wehrli ◽  
Marta Vidorreta ◽  
...  
Keyword(s):  
Blood Flow ◽  
Uterine Artery ◽  
Artery Blood Flow ◽  
4D Flow Mri ◽  
4D Flow ◽  
Human Pregnancy ◽  
Flow Mri ◽  
Mri Evaluation ◽  
In Vivo Validation

scholarly journals Impact of Pulmonary Venous Inflow on Cardiac Flow Simulations: Comparison with In Vivo 4D Flow MRI

2018 ◽  
Vol 47 (2) ◽  
pp. 413-424 ◽  
Author(s):  
Jonas Lantz ◽  
Vikas Gupta ◽  
Lilian Henriksson ◽  
Matts Karlsson ◽  
Anders Persson ◽  
...  
Keyword(s):  
4D Flow Mri ◽  
4D Flow ◽  
Flow Simulations ◽  
Flow Mri

scholarly journals A technique for intra-procedural blood velocity quantitation using time-resolved 2D digital subtraction angiography

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Carson Hoffman ◽  
Sarvesh Periyasamy ◽  
Colin Longhurst ◽  
Rafael Medero ◽  
Alejandro Roldan-Alzate ◽  
...  
Keyword(s):  
Blood Velocity ◽  
Contrast Injection ◽  
4D Flow ◽  
Flow Probe ◽  
Time Resolved ◽  
Accuracy And Precision ◽  
Flow Mri ◽  
Projection Angle

Abstract Background 2D digital subtraction angiography (DSA) is utilized qualitatively to assess blood velocity changes that occur during arterial interventions. Quantitative angiographic metrics, such as blood velocity, could be used to standardize endpoints during angiographic interventions. Purpose To assess the accuracy and precision of a quantitative 2D DSA (qDSA) technique and to determine its feasibility for in vivo measurements of blood velocity. Materials and methods A quantitative DSA technique was developed to calculate intra-procedural blood velocity. In vitro validation was performed by comparing velocities from the qDSA method and an ultrasonic flow probe in a bifurcation phantom. Parameters of interest included baseline flow rate, contrast injection rate, projection angle, and magnification. In vivo qDSA analysis was completed in five different branches of the abdominal aorta in two 50 kg swine and compared to 4D Flow MRI. Linear regression, Bland-Altman, Pearson’s correlation coefficient and chi squared tests were used to assess the accuracy and precision of the technique. Results In vitro validation showed strong correlation between qDSA and flow probe velocities over a range of contrast injection and baseline flow rates (slope = 1.012, 95% CI [0.989,1.035], Pearson’s r = 0.996, p < .0001). The application of projection angle and magnification corrections decreased variance to less than 5% the average baseline velocity (p = 0.999 and p = 0.956, respectively). In vivo validation showed strong correlation with a small bias between qDSA and 4D Flow MRI velocities for all five abdominopelvic arterial vessels of interest (slope = 1.01, Pearson’s r = 0.880, p = <.01, Bias = 0.117 cm/s). Conclusion The proposed method allows for accurate and precise calculation of blood velocities, in near real-time, from time resolved 2D DSAs.

scholarly journals A dual-VENC 4D Flow MRI Framework for Analysis of Subject-Specific Heterogeneous non-linear Vessel Deformation

2020 ◽  
Author(s):  
Jamie Concannon ◽  
Niamh Hynes ◽  
Marie McMullan ◽  
Evelyn Smyth ◽  
Kevin Mattheus Moerman ◽  
...  
Keyword(s):  
In Silico ◽  
Cardiac Cycle ◽  
Human Aorta ◽  
4D Flow Mri ◽  
4D Flow ◽  
Imaging Protocol ◽  
Subject Specific ◽  
Non Linear ◽  
Flow Mri

Advancement of subject-specific in-silico medicine requires new imaging protocols tailored to specific anatomical features, paired with new constitutive model development based on structure/function relationships. In this study we develop a new dual-VENC 4D Flow MRI protocol that provides unprecedented spatial and temporal resolution of in-vivo aortic deformation. All previous dual-VENC 4D Flow MRI studies in the literature focus on an isolated segment of the aorta, which fail to capture the full spectrum of aortic heterogeneity that exists along the vessel length. The imaging protocol developed provides high sensitivity to all blood flow velocities throughout the entire cardiac cycle, overcoming the challenge of accurately measuring the highly unsteady non-uniform flow field in the aorta. Cross sectional area change, volumetric flow rate, and compliance are observed to decrease with distance from the heart, while pulse wave velocity is observed to increase. A non-linear aortic lumen pressure-area relationship is observed throughout the aorta, such that a high vessel compliance occurs during diastole, and a low vessel compliance occurs during systole. This suggests that a single value of compliance may not accurately represent vessel behaviour during a cardiac cycle in-vivo. This high-resolution MRI data provides key information on the spatial variation in non-linear aortic compliance which can significantly advance the state-of-the-art of in-silico diagnostic techniques for the human aorta.

scholarly journals Assessment of turbulent blood flow and wall shear stress in aortic coarctation using image-based simulations

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Romana Perinajová ◽  
Joe F. Juffermans ◽  
Jonhatan Lorenzo Mercado ◽  
Jean-Paul Aben ◽  
Leon Ledoux ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Turbulent Flows ◽  
Patient Specific ◽  
4D Flow Mri ◽  
4D Flow ◽  
Local Flow ◽  
Flow Mri ◽  
Wall Shear

AbstractIn this study, we analyzed turbulent flows through a phantom (a 180$$^{\circ }$$ ∘ bend with narrowing) at peak systole and a patient-specific coarctation of the aorta (CoA), with a pulsating flow, using magnetic resonance imaging (MRI) and computational fluid dynamics (CFD). For MRI, a 4D-flow MRI is performed using a 3T scanner. For CFD, the standard $$k-\epsilon $$ k - ϵ , shear stress transport $$k-\omega $$ k - ω , and Reynolds stress (RSM) models are applied. A good agreement between measured and simulated velocity is obtained for the phantom, especially for CFD with RSM. The wall shear stress (WSS) shows significant differences between CFD and MRI in absolute values, due to the limited near-wall resolution of MRI. However, normalized WSS shows qualitatively very similar distributions of the local values between MRI and CFD. Finally, a direct comparison between in vivo 4D-flow MRI and CFD with the RSM turbulence model is performed in the CoA. MRI can properly identify regions with locally elevated or suppressed WSS. If the exact values of the WSS are necessary, CFD is the preferred method. For future applications, we recommend the use of the combined MRI/CFD method for analysis and evaluation of the local flow patterns and WSS in the aorta.

scholarly journals In vivo quantification of blood mixing in single ventricle patients with Fontan circulation using 4D flow MRI

2013 ◽  
Vol 15 (S1) ◽  
Author(s):  
Kelly B Jarvis ◽  
Susanne Schnell ◽  
Maya Gabbour ◽  
Alex J Barker ◽  
Ramona Lorenz ◽  
...  
Keyword(s):  
Single Ventricle ◽  
Fontan Circulation ◽  
4D Flow Mri ◽  
4D Flow ◽  
Flow Mri

scholarly journals Hemodynamic study of TCPC using in vivo and in vitro 4D Flow MRI and numerical simulation

2015 ◽  
Vol 48 (7) ◽  
pp. 1325-1330 ◽  
Author(s):  
Alejandro Roldán-Alzate ◽  
Sylvana García-Rodríguez ◽  
Petros V. Anagnostopoulos ◽  
Shardha Srinivasan ◽  
Oliver Wieben ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
4D Flow Mri ◽  
4D Flow ◽  
Flow Mri ◽  
Hemodynamic Study

Quantification of Retrograde Blood Flow in the Descending Aorta Using Transesophageal Echocardiography in Comparison to 4D Flow MRI

2015 ◽  
Vol 39 (5-6) ◽  
pp. 287-292 ◽  
Author(s):  
Thomas Wehrum ◽  
Miriam Kams ◽  
Felix Günther ◽  
Primrose Beryl ◽  
Werner Vach ◽  
...  
Keyword(s):  
Blood Flow ◽  
Transesophageal Echocardiography ◽  
Threshold Value ◽  
Retrograde Flow ◽  
4D Flow Mri ◽  
4D Flow ◽  
Descending Aorta ◽  
Flow Mri ◽  
The Mean

Background: Retrograde diastolic blood flow in the proximal descending aorta (DAo), which connects plaques ≥4 mm thickness with brain-supplying arteries, has previously been identified as a possible source of brain embolism. Currently, only 4D flow MRI is able to visualize and quantify potential retrograde embolization pathways in the DAo in-vivo. Hence, it was our aim to test if the extent of retrograde flow could be estimated by routine 2D transesophageal echocardiography (TEE). Methods: Forty-eight acute stroke patients were prospectively included and they underwent Doppler examinations of the transition zone between the aortic arch and the DAo using a 20 mm 2D sample volume in longitudinal section at 90-140° Doppler angle during routine TEE. Velocity-time-integrals (VTI) were studied for antegrade and retrograde velocities and the ratio (VTIratio) was calculated and correlated with the length of retrograde pathlines at that site, which were visualized using 4D flow MRI at 3-Tesla. A receiver operating characteristic (ROC) curve was used to evaluate a threshold value of VTIratio in differentiating large (≥3 cm) from small (<3 cm) retrograde flow extent. Results: At the TEE measurement site, the mean VTIratio was 0.53 ± 0.16 and the mean length of retrograde pathlines reaching back into the aortic arch was 3.1 ± 1.4 cm. VTIratio was an independent predictor of retrograde pathline length (r = 0.44; p = 0.002). ROC analysis identified a VTIratio threshold value of 0.6012 with a sensitivity of 0.5, a specificity of 0.92, and positive and negative predictive values of 0.84 and 0.68, respectively. Accordingly, 11 (22.91%) patients had a VTIratio cutoff value ≥0.6012 and corresponding retrograde pathline length ≥3 cm in 4D flow MRI. Conclusions: TEE allows predicting the length of retrograde pathlines. Hence, it may offer a cost-effective way to investigate independent predictors of DAo flow reversal in large-scale studies. However, TEE is only of limited value as a screening tool for high retrograde flow in a clinical setting, as only ∼23% of patients can be spared 4D flow MRI, which remains indispensable for the exact assessment of individual embolization pathways from plaques of the DAo in-vivo.

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