Implications of bulk motion for diffusion-weighted imaging experiments: effects, mechanisms, and solutions

Area of Science:

• Medical Imaging
• Neuroscience
• Biophysics

Background:

• Bulk motion introduces artifacts in diffusion-weighted imaging (DWI) experiments.
• Understanding translational and rotational motion is crucial for accurate brain imaging.

Purpose of the Study:

• To review the effects of bulk motion on DWI experiments.
• To examine methods for correcting motion-induced artifacts in two-dimensional brain imaging.

Main Methods:

• Categorization of motion amelioration techniques into intrinsically insensitive, adaptable, and corrective methods.
• Evaluation of techniques including motion-compensated diffusion-weighting, single-shot EPI, projection reconstruction, line scanning, FLASH, RARE, and navigator echoes.

Main Results:

• Single-shot EPI and projection reconstruction offer high-quality images without sensitivity compromise.
• FLASH and RARE sequences achieve motion insensitivity at the cost of 50% sensitivity reduction.
• Navigator echoes and artifact minimization methods are discussed for motion correction.

Conclusions:

• Bulk motion presents significant challenges in diffusion imaging.
• Various methods exist to mitigate motion artifacts, each with specific trade-offs in sensitivity and image quality.
• Further advancements are needed to optimize diffusion imaging in the presence of bulk motion.