Analytical Ground Truth for Phase-Contrast MRI Experiments and Simulations: Open-Source Precision-Controlled...

Area of Science:

• Medical Imaging
• Biophysics
• Magnetic Resonance Imaging

Background:

• Accurate evaluation of motion sensitivity in MRI sequences is crucial for reliable flow quantification.
• Existing methods for assessing displacement artifacts and velocity/acceleration sensitivity in phase-contrast MRI (PC-MRI) can be limited in reproducibility and scope.
• Bridging the gap between computational simulations and experimental validation in MRI research requires standardized tools.

Purpose of the Study:

• To introduce a fully open-source, air-driven, bidirectional rotational MRI phantom.
• To enable accurate and reproducible evaluation of displacement artifacts for any MRI sequence.
• To assess velocity field and acceleration sensitivity for PC-MRI sequences with analytically defined motion.

Main Methods:

• A rotational phantom was bidirectionally driven using controlled airflow.
• Polyvinylpyrrolidone-water mixture filled the rotating cylinder, monitored by a laser tachometer.
• Vendor and open-source PC-MRI sequences were tested on a 3T MRI system, with results compared against ground truth data.

Main Results:

• Displacement errors were approximately 10% radial stretch at physiological velocities.
• Apparent acceleration sensitivity was measured at 5% of v_enc.
• Excellent agreement was observed between Bloch simulations and experimental results.

Conclusions:

• The developed phantom provides a precise and repeatable method for evaluating MRI sequence motion sensitivity.
• It serves as a potential reference standard, with suggestions for reporting sequence timing parameters to enhance comparability.
• This framework standardizes PC-MRI validation, improving quality assurance and flow quantification accuracy.