Data Stitching for Dynamic Field Monitoring With NMR Probes.

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Biophysics
• Medical Physics

Background:

• Standard field monitoring in MRI is limited by resolution and readout length.
• Characterizing dynamic magnetic fields is crucial for advanced MRI sequences.

Purpose of the Study:

• To propose a novel stitching method for characterizing MRI sequences with enhanced resolution and readout length.
• To overcome limitations of standard field monitoring approaches.

Main Methods:

• A stitching method combining segment-specific dynamic field measurements across consecutive TRs.
• Demonstrated using 2D spiral sequences at 10.5T and 7T with simulated and experimental MRI data.
• Validated in human brain imaging at 7T and compared against gradient impulse response function (GIRF) prediction.

Main Results:

• The stitching method outperformed standard approaches at 10.5T, providing accurate dynamic field measurements.
• At 7T, it yielded comparable results to standard methods where applicable and sensible measurements where standard methods failed.
• Improved image reconstruction for both simulated and experimental MRI data at 7T.

Conclusions:

• The proposed stitching method effectively characterizes challenging imaging gradients using commercial hardware.
• It does not assume a linear gradient system, offering broad utility for ultrahigh-resolution MRI at ultrahigh fields.