Partial fourier shells trajectory for non-cartesian MRI.

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Medical Imaging Physics

Background:

• Non-Cartesian MRI trajectories, like shells, offer efficient 3D isotropic acquisition.
• Partial Fourier acquisition accelerates Cartesian MRI by reducing k-space samples.
• Integrating Partial Fourier with non-Cartesian trajectories like shells for non-iterative reconstruction is challenging due to trajectory variability.

Purpose of the Study:

• To develop an asymmetric shells trajectory compatible with non-iterative homodyne reconstruction.
• To enable Partial Fourier acquisition within the shells trajectory framework.
• To automate the design of the trajectory and gradient waveform for this new method.

Main Methods:

• Designed an asymmetric shells trajectory with automated gradient waveform design for Partial Fourier acquisition.
• Developed a non-iterative image reconstruction framework tailored for the proposed trajectory.
• Validated the method using phantom and in vivo brain scans with spoiled gradient echo (SPGR) and magnetization-prepared (MP) shells.

Main Results:

• Demonstrated the feasibility of the proposed asymmetric shells trajectory for Partial Fourier acquisition.
• Showcased a successful non-iterative reconstruction for the designed trajectory.
• Confirmed that the Partial Fourier shells trajectory preserves image contrast and sampling efficiency.

Conclusions:

• The developed Partial Fourier shells trajectory successfully reduces MRI acquisition time.
• This method maintains the benefits of fully sampled shells trajectories, including image contrast and efficiency.
• The approach offers a practical solution for accelerating 3D non-Cartesian MRI scans.