Autocalibrating motion-corrected wave-encoding for highly accelerated free-breathing abdominal MRI.

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Medical Imaging Technology

Background:

• Abdominal MRI is crucial for diagnosis but often limited by respiratory motion.
• Accelerated imaging techniques are needed to reduce scan times and patient discomfort.
• Existing methods struggle to adequately correct for motion in free-breathing abdominal scans.

Purpose of the Study:

• To develop and evaluate a motion-robust wave-encoding technique for highly accelerated free-breathing abdominal MRI.
• To improve image quality and reduce motion artifacts in accelerated abdominal MRI acquisitions.

Main Methods:

• A comprehensive 3D wave-encoding method was developed, incorporating auto-calibration, intrinsic butterfly navigators for motion tracking, variable-density sampling for compressed sensing, and golden-angle radial-Cartesian hybrid view-ordering.
• Localized rigid motion correction was combined with parallel imaging and compressed sensing reconstruction.
• The method was tested on six subjects and compared against standard accelerated Cartesian acquisition with and without respiratory triggering, using quantitative image quality metrics.

Main Results:

• Wave-encoding significantly reduced aliasing and blurring in respiratory-triggered scans compared to standard Cartesian acquisition (P < 0.05).
• The proposed method demonstrated significantly superior motion correction in non-respiratory-triggered scans compared to standard motion-corrected Cartesian acquisition (P < 0.01).

Conclusions:

• The developed wave-encoding technique effectively reduces motion artifacts in highly accelerated free-breathing abdominal MRI.
• This method improves overall image quality, enabling faster and more robust abdominal imaging.