Three-dimensional motion tracking with volumetric phase contrast MR velocity imaging

Area of Science:

• Medical Imaging
• Biophysics
• Computational Science

Background:

• Single-slice cine-phase contrast magnetic resonance imaging (MRI) motion tracking is limited for complex 3D movements.
• Accurate trajectory reconstruction necessitates volumetric data, especially for nontrivial motion and deformation.

Purpose of the Study:

• To present a novel three-dimensional (3D) Fourier tracking method for enhanced motion tracking using volumetric MRI data.
• To evaluate the accuracy and performance of this 3D tracking algorithm.

Main Methods:

• Developed a 3D Fourier tracking algorithm that reconstructs material point trajectories by analyzing their harmonics.
• Incorporated an intra-voxel linear spatial model to mitigate tracking errors from reduced spatial resolution, particularly in the slice (z) direction.
• Validated the method using simulated computer-generated datasets and in vitro phantom data acquired via both multi-slice 2D and 3D sequences.

Main Results:

• The 3D Fourier tracking method accurately estimates all reconstructible harmonics of a trajectory at a given temporal sampling rate.
• The algorithm demonstrated high sub-voxel tracking accuracy in both simulated and experimental datasets.
• Performance was robust across various simulated motion patterns and phantom data types.

Conclusions:

• The presented 3D Fourier tracking method significantly improves motion tracking accuracy compared to single-slice techniques.
• Volumetric data combined with this harmonic analysis approach is essential for precise 3D motion and deformation reconstruction in MRI.
• The method offers a robust solution for high-accuracy sub-voxel motion tracking in biomedical applications.