Real-time 4D phase unwrapping applied to magnetic resonance elastography

Area of Science:

• Medical Imaging
• Biophysics

Background:

• Phase amplitude is a key signal in magnetic resonance elastography (MRE).
• Exploiting phase amplitude in MRE is challenging due to phase wrap.
• Limited experimental design options exist for MRE phase wrap issues.

Purpose of the Study:

• To address limitations in MRE experimental design caused by phase wrap.
• To develop new algorithms, heuristic strategies, and a user interface for MRE phase unwrapping.
• To enhance the utilization of phase amplitude as a signal source in MRE.

Main Methods:

• Developed a test dataset with variations in nested wrap, gradient, and noise level.
• Created PhaseTools, a new application implementing three real-time phase-unwrapping algorithms (<3 min for 4D MRE).
• Applied algorithms to typical and challenging MRE datasets, including edge cases.

Main Results:

• PhaseTools algorithms demonstrated performance comparable to established, time-intensive methods.
• Established guidelines for optimal algorithm usage.
• Validated algorithm performance on diverse MRE datasets.

Conclusions:

• PhaseTools significantly increases signal-to-noise ratio in MRE with minimal computational cost.
• PhaseTools provides robust, real-time phase unwrapping for MRE.
• The software is freely released, promoting wider accessibility for phase-based imaging research.