Dephasing optimization through coherence order pathway selection (DOTCOPS) for improved crusher schemes in MR...

Area of Science:

• Magnetic Resonance
• Spectroscopy
• Signal Processing

Background:

• Spurious echoes and mislocalization in magnetic resonance spectroscopy (MRS) arise from unwanted coherence pathways.
• Existing methods for eliminating these pathways are often sequence-specific and may affect desired signals.

Purpose of the Study:

• To develop a universal algorithm for robustly eliminating all unwanted coherence pathways in arbitrary MRS experiments.
• To reduce the impact of spurious echoes and mislocalization by adjusting crusher gradient amplitudes.

Main Methods:

• Modeled the effect of crushing gradients on all coherence pathways based on physical principles.
• Optimized a cost function to maximize crushing of unwanted pathways while preserving desired ones.
• Validated the algorithm using sLASER and MEGA-sLASER sequences with phantom and in vivo data.

Main Results:

• Demonstrated enhanced crushing power for two MRS sequences compared to literature schemes.
• Successfully applied the method to both phantom and in vivo datasets.
• Showcased improved performance in reducing artifacts.

Conclusions:

• Developed a novel algorithm and software applicable to any MRS pulse sequence and spin system.
• Addressed a long-standing challenge in in vivo MRS.
• Expected to significantly enhance data quality across virtually all MRS applications.