Using UNFOLD to remove artifacts in parallel imaging and in partial-Fourier imaging

Area of Science:

• Medical Imaging
• Magnetic Resonance Imaging
• Image Reconstruction

Background:

• Dynamic MRI requires high acquisition speed to capture temporal variations.
• Existing acceleration methods like partial-Fourier and parallel imaging (SMASH, SENSE) can introduce artifacts and noise.
• There is a need for MRI acceleration techniques that minimize artifacts and noise.

Purpose of the Study:

• To significantly accelerate dynamic MRI acquisition.
• To introduce minimal artifacts or noise amplification during accelerated MRI.
• To improve the performance of existing dynamic MRI acceleration methods.

Main Methods:

• A temporal strategy based on the UNaliasing by Fourier-encoding the Overlaps in the temporaL Dimension (UNFOLD) method was developed.
• The UNFOLD method modifies the sampling function to change across time-frames, acquiring unique k-space data at each time-point.
• UNFOLD was integrated with established dynamic MRI techniques, including partial-Fourier, SMASH, and SENSE imaging.

Main Results:

• The UNFOLD method significantly reduces artifacts and amplified noise when incorporated into dynamic MRI.
• UNFOLD enables companion acceleration methods to operate effectively at higher settings than previously possible.
• The strategy allows for substantial acceleration of image acquisition with minimal image degradation.

Conclusions:

• The UNFOLD method offers an indirect but powerful approach to accelerating dynamic MRI.
• By mitigating artifacts and noise, UNFOLD enhances the feasibility and reliability of accelerated MRI techniques.
• This strategy improves the overall quality and speed of dynamic MRI, aiding in the resolution of temporal variations.