Velocity Measurement in Carotid Artery: Quantitative Comparison of Time-Resolved 3D Phase-Contrast MRI and Image-based Computational Fluid Dynamics

Abstract

Background:Understanding hemodynamic environment in vessels is important for realizing the mechanisms leading to vascular pathologies.Objectives:Three-dimensional velocity vector field in carotid bifurcation is visualized using TR 3D phase-contrast magnetic resonance imaging (TR 3D PC MRI) and computational fluid dynamics (CFD). This study aimed to present a qualitative and quantitative comparison of the velocity vector field obtained by each technique.Subjects and Methods:MR imaging was performed on a 30-year old male normal subject. TR 3D PC MRI was performed on a 3 T scanner to measure velocity in carotid bifurcation. 3D anatomical model for CFD was created using images obtained from time-of-flight MR angiography. Velocity vector field in carotid bifurcation was predicted using CFD and PC MRI techniques. A statistical analysis was performed to assess the agreement between the two methods.Results:Although the main flow patterns were the same for the both techniques, CFD showed a greater resolution in mapping the secondary and circulating flows. Overall root mean square (RMS) errors for all the corresponding data points in PC MRI and CFD were 14.27% in peak systole and 12.91% in end diastole relative to maximum velocity measured at each cardiac phase. Bland-Altman plots showed a very good agreement between the two techniques. However, this study was not aimed to validate any of methods, instead, the consistency was assessed to accentuate the similarities and differences between Time-resolved PC MRI and CFD.Conclusion:Both techniques provided quantitatively consistent results of in vivo velocity vector fields in right internal carotid artery (RCA). PC MRI represented a good estimation of main flow patterns inside the vasculature, which seems to be acceptable for clinical use. However, limitations of each technique should be considered while interpreting results.

Evaluation of 4D flow MRI-based non-invasive pressure assessment in aortic coarctations

“…The comparison between velocity color maps along the descending aorta further confirmed the accuracy of the FSI model, which also captured late systolic secondary flow features that were not detected by 4D flow owing to its lower spatial resolution. Also, RMSE between velocity magnitude color maps ranged from 16% to 36%; despite the higher complexity of our fluid domain, these results are in agreement with a previous study focused on the CFD vs. 4D flow comparison in a carotid artery (Sarrami-Foroushani et al, 2015), which reported RRMSE values ranging from 10% to 20%.…”

Comparison of Newtonian and Non-newtonian Fluid Models in Blood Flow Simulation in Patients With Intracranial Arterial Stenosis

“…In the patient-specific model for transient simulation, we imposed physiological pressure waveform (range: 72–129 mmHg, Figure 1C ) at the ICA inlet ( Sarrami-Foroushani et al, 2015 ). Due to the lack of in vivo measurements of flow velocity at MCA/ACA outlets, we adopted 3-element Windkessel models, to avoid possible errors caused by possibly inaccurate assumptions in blood pressure or flow rate ( Figure 1C ).…”

Four-Dimensional Flow Magnetic Resonance Imaging for Assessment of Velocity Magnitudes and Flow Patterns in The Human Carotid Artery Bifurcation: Comparison with Computational Fluid Dynamics

“…It is a feasible method of measuring the 3D distribution of the blood velocity vector field in vivo, allowing 3D flow structures to be examined with a single scan [10,11]. 4D flow MRI has been used to obtain data about the blood-flow characteristics of the cerebral vascular system, the aorta, as well as the carotid arteries, and can highlight local and global hemodynamic conditions [5,8,9,[12][13][14].…”