Self-Navigated Three-Dimensional Ultrashort Echo Time Technique for Motion-Corrected Skull MRI.

Area of Science:

• Medical Imaging
• Radiology
• Biophysics

Background:

• Ultrashort echo time (UTE) MRI detects short T2 relaxation signals, enabling radiation-free skull imaging as a CT alternative.
• Long scan times in UTE MRI are susceptible to motion artifacts, limiting its clinical application.

Purpose of the Study:

• To develop a motion-resistant, self-navigated 3D UTE MRI sequence for improved skull imaging.
• To implement retrospective motion correction and k-space trajectory calibration for enhanced image quality.

Main Methods:

• A self-navigated 3D UTE pulse sequence utilizing dual-RF, dual-echo imaging.
• Retrospective motion correction based on self-navigator data and golden-means k-space trajectory.
• Hardware-related k-space trajectory error correction via a calibration scan.

Main Results:

• Effective removal of motion artifacts in in vivo studies.
• Clear depiction of skull bone voxels with corrected UTE MRI data.
• Demonstrated robustness to intermittent head motions during scanning.

Conclusions:

• The developed self-navigated UTE MRI with motion correction provides robust, high-resolution skull imaging.
• This technique offers a promising radiation-free alternative to CT for skull visualization.
• Correction of k-space trajectory errors is crucial for optimal bone contrast in UTE MRI.