Impact of Partial Echo on 4D Flow MRI: The Insight From Synthetic MRI

Area of Science:

• Medical Imaging
• Fluid Dynamics
• Computational Science

Background:

• 4D flow MRI is crucial for cardiovascular imaging.
• Flow misregistration artifacts can impact accuracy.
• Partial echo (PE) sequences are an alternative to full echo (FE) sequences.

Purpose of the Study:

• To evaluate the impact of partial echo (PE) on 4D flow MRI.
• To compare PE and full echo (FE) sequences using in silico simulations.
• To assess the utility of coupled MRI-CFD simulations for sequence development.

Main Methods:

• Simulated two 4D flow MRI sequences: FE and PE (echo symmetry fraction of 0.75).
• Employed in silico MRI-CFD coupled simulations.
• Utilized a pulsatile flow phantom with sinusoidal and physiological inflow profiles.

Main Results:

• PE-based MRI-CFD simulations showed better agreement with CFD than FE-based simulations.
• This improved compliance was observed for both sinusoidal and physiological inflow types.
• PE effectively reduced flow misregistration artifacts.

Conclusions:

• The benefits of reduced flow misregistration with PE outweigh the k-space filling drawback.
• The MRI-CFD framework is valuable for optimizing MRI sequence design.
• This approach aids in stratifying sources of error in MRI sequences.