Gradient waveform pre-emphasis based on the gradient system transfer function

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Image Reconstruction
• Signal Processing

Background:

• K-space trajectory distortions in MRI lead to image artifacts.
• The gradient system transfer function (GSTF) characterizes these distortions.

Purpose of the Study:

• To utilize the GSTF for determining pre-emphasis to achieve undistorted gradient output.
• To enable accurate k-space trajectory reconstruction in MRI.

Main Methods:

• Determined the MR system's GSTF using standard hardware.
• Applied GSTF for trajectory prediction and gradient waveform pre-emphasis.
• Tested on gradient-echo sequences with phase-encoding modulation and spiral read-out, using phantoms and in vivo head scans.

Main Results:

• GSTF-based pre-emphasis successfully suppressed image artifacts.
• Achieved comparable results to GSTF-based post-correction during image reconstruction.
• Pre-emphasis allowed reconstruction using the initially intended k-space trajectory.

Conclusions:

• The GSTF is effective for novel pre-emphasis strategies in MRI.
• GSTF-based pre-emphasis can be applied to any MRI sequence type.
• This approach enhances image quality by correcting trajectory distortions.