Scout-based Multi-Echo NAvigator (SMENA) for high temporal resolution motion and B ₀ estimation and correction:...

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Medical Physics
• Image Reconstruction

Background:

• Motion and B0 inhomogeneity are significant challenges in gradient-echo MRI.
• Accurate estimation and correction are crucial for robust image quality.

Purpose of the Study:

• Develop Scout-based Multi-Echo NAvigator (SMENA) for joint motion and B0 inhomogeneity estimation.
• Achieve high temporal resolution (~200 ms) with minimal scan time.

Main Methods:

• SMENA utilizes rapid multi-echo scout and navigator acquisitions.
• Joint estimation of motion and B0 maps via a model-based optimization framework.
• Evaluated in simulations and in vivo with prospective motion experiments.

Main Results:

• Accurate joint motion and B0 estimation achieved in simulations and in vivo.
• Joint correction reduced rotation/translation errors and improved image quality (10.4% NRMSE vs 31.6%).
• High-temporal-resolution tracking enhanced reconstruction during continuous motion and deep breathing.

Conclusions:

• SMENA enables high-temporal-resolution joint motion and B0 estimation.
• Offers a practical, low-cost solution for motion- and B0-robust MRI.