First experiences of local pulse wave velocity measurements in 4D-MRI in focally stented femoropopliteal arteries

VASA ◽  
2021 ◽  
Author(s):  
Ingo Hermann ◽  
Tetyana Shchetynska-Marinova ◽  
Klaus Amendt ◽  
Anna-Lena Hohneck ◽  
Stefan O. Schönberg ◽  
...  
Keyword(s):  
Young Adult ◽  
Pulse Wave ◽  
Arterial Disease ◽  
Velocity Measurements ◽  
Clinical Tool ◽  
4D Flow ◽  
Femoral Arteries ◽  
Flow Mri ◽  
Adult Volunteers

Summary: Background: In peripheral arterial disease (PAD) the femoropopliteal (FP) artery is the most frequently recanalized lower limb artery. Stent-based interventions change the biomechanical properties of FP arteries. However, no clinical tool for functional imaging is established for quantitative measurements in vivo. Four-dimensional-flow magnetic resonance imaging enables a detailed evaluation of the hemodynamics of the central and – more challenging – the peripheral arteries. The present study aimed to determine the feasibility of assessing pulse wave velocities (PWV) as a marker of vessel stiffness in PAD patients with multiple spot stents and to compare the values with age-matched subjects and young-adult healthy subjects. Patients and methods: Contrast-free 4D-flow MRI was performed in seven PAD patients with focally stented FP arteries, five age-matched subjects after exclusion of PAD, and five young, healthy adults. PWV values were calculated from flow curves by using the foot-to-foot method. Results: Four-D-flow MRI sequences offering high spatial and temporal resolution enables quantification of flow velocity measurements and estimation of PWVs. Assessment of segmental PWV as a surrogate of vascular stiffness in focally stented femoral arteries is feasible. PWV values across all groups were 15.6±5.2 m/s, 13.3±4.1 m/s, and 9.9±2.2 m/s in PAD patients, senior-aged volunteers, and young-adult volunteers respectively. PWV values in PAD patients were similar with those in the senior-aged volunteers group (15.6±5.2 vs. 13.3 ±4.1 years, p=0.43). However, when compared to the young-adult volunteers, PAD patients had a statistically significantly higher mean local PWV (15.6±5.2 m/s vs. 9.9±2.2 m/s, p<0.05). Conclusions: Calculating segmental PWV in the femoral arteries is feasible in PAD patients with focally stented FP arteries. PWV values in PAD patients were similar to those in senior-aged volunteers, both of which were higher than in young-adult volunteers.

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

Accounting for Differences Between Echo Particle Image Velocimetry (EPIV) and Pulse Wave Doppler (PWD) Velocity Measurements

2009 ◽  
Author(s):  
Andrew M. Walker ◽  
Clifton R. Johnston ◽  
Gary M. Dobson
Keyword(s):  
Shear Stress ◽  
Particle Image Velocimetry ◽  
Particle Image ◽  
Pulse Wave ◽  
Velocity Measurements ◽  
Image Velocimetry ◽  
University Of Calgary ◽  
Beam Thickness ◽  
The University

Currently, an echo particle image velocimetry (ePIV) system for the investigation of in vivo blood flow and shear stress is under development at the University of Calgary. To date, encouraging preliminary results have been obtained when comparing ePIV derived velocities to analytical solutions. However, large discrepancies were noted between our steady state ePIV derived velocities and velocities measured using pulse wave Doppler (PWD). Ultrasound beam thickness, off axis centerline measurements and PWD angle of interrogation likely account for the differences observed.

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 Sensitivities of in vivo markers of arterial organ damage in patients with peripheral atherosclerosis

VASA ◽  
2018 ◽  
Vol 47 (1) ◽  
pp. 30-35 ◽  
Author(s):  
Martina Frick ◽  
Frederic Baumann ◽  
Beate Sick ◽  
Ian B. Wilkinson ◽  
Beatrice Amann-Vesti ◽  
...  
Keyword(s):  
Pulse Wave Velocity ◽  
Wave Velocity ◽  
Pulse Pressure ◽  
Pulse Wave ◽  
Ankle Brachial Index ◽  
Arterial Disease ◽  
Organ Damage ◽  
Altman Analysis ◽  
Bland Altman Analysis

Abstract. Background: Biomarkers of vascular diseases such as ankle-brachial index (ABI), peripheral pulse pressure (pPP), central pulse pressure (cPP), and pulse wave velocity (PWV) allow assessment of arterial organ damage (AOD). However, the utility of markers other than ABI in patients with peripheral arterial disease (PAD), which are also associated with a significant increase of cardiovascular events, remains unclear. Patients and methods: Asymptomatic (n = 21) and symptomatic patients (n = 46) with a positive sonography for PAD or history of lower limb revascularization were included. ABI, pPP, cPP, and PWV were assessed. PWV were performed using a brachial cuff-based method (aortic PWV (aPWV)) and oscillography (carotid-femoral pulse wave velocity (cfPWV)), respectively. The two methods for PWV were compared using Bland Altman analysis. Sensitivities of ABI, pPP, cPP, cfPWV, and aPWV for AOD were calculated. Results: Sixty-seven patients (35.8 % female, mean age 69, range 39–91 years) had a significantly higher aPWV than cfPWV (median 10.5 m/s (IQR: 8.8–12.65 m/s) vs. median 9.0 m/s (IQR: 7.57–10.55 m/s), p = 0.0013). There was no correlation between cfPWV and age (r = 0.311, p = 0.116). Bland Altman analysis revealed a mean difference of -1.04 (-2SD; -6.38 to + 2SD; 4.31). The sensitivities for AOD were 68.7 % for ABI, 61.2 % for aPWV, 40.3 % for cfPWV, 31.3 % for peripheral PP, and 10.4 % for central aortic PP (p < 0.001). Conclusions: Brachial-derived aPWV differs from the gold standard assessment (cfPWV), which may be underestimated in PAD due to atherosclerotic obstructions along the aorto-iliac segment. The sensitivities of noninvasive in vivo markers of AOD vary widely and tend to underestimate the actual presence of AOD.

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