A motion tracking method that applies a spread spectrum communication technique to tagging MR imaging

Area of Science:

• Medical Imaging
• Biophysics

Background:

• Magnetic Resonance Imaging (MRI) is crucial for medical diagnostics.
• Accurate motion tracking is essential for quantitative MRI analysis.
• Current tagging methods have limitations in precision and speed.

Purpose of the Study:

• To develop and assess a new MRI motion tracking method using digital codes.
• To encode object position information using tagged MR images.
• To evaluate the feasibility of this method in stationary and moving phantoms.

Main Methods:

• Utilized a segmented fast low angle shot cine sequence (FLASH) with spatial modulation of magnetization (SPAMM) pulses.
• Encoded position information as 7-bit code words using 7 distinct tag patterns.
• Employed spread spectrum communication principles for encoding and decoding tag patterns.
• Acquired 7 images per acquisition, each with a unique tag pattern.

Main Results:

• Achieved comparable pixel position identification to conventional tagging in stationary phantoms with improved signal-to-noise ratio (SNR).
• Successfully decoded pixel positions on a pixel-by-pixel basis in a moving phantom.
• Detected phantom motion through correlation coefficient calculation of code words.

Conclusions:

• Introduced a spread spectrum communication technique applied to tagging MR imaging.
• Demonstrated the potential of using tag patterns as digital codes for motion tracking.
• Showcased the method's capability for detecting pixel position with sub-pixel resolution.