Partially parallel imaging with phase-sensitive data: Increased temporal resolution for magnetic resonance...

Area of Science:

• Medical Imaging
• Biophysics
• Therapeutic Monitoring

Background:

• Magnetic resonance temperature imaging (MRTI) is crucial for monitoring thermal ablation therapies, enhancing treatment efficacy and patient safety.
• Rapidly heating tissues necessitate high temporal resolution in MRTI, but current methods often compromise image resolution, slice coverage, or phase sensitivity.
• Partially parallel imaging (PPI) techniques present a solution for improved temporal resolution without these trade-offs.

Purpose of the Study:

• To evaluate the feasibility of using partially parallel imaging techniques for magnetic resonance temperature imaging.
• To assess the impact of PPI on temporal resolution, image quality, and phase sensitivity in MRTI.
• To determine if relative phase changes can be reliably measured using PPI for dynamic MR temperature monitoring.

Main Methods:

• Utilized partially parallel imaging techniques with reconstruction filters constant across dynamic image series.
• Acquired phase-difference-sensitive data using arrays of surface coils for both PPI and non-accelerated acquisitions.
• Compared average phase differences and phase noise between PPI and fully Fourier encoded images.

Main Results:

• Relative phase changes in MRTI can be reliably measured using PPI techniques.
• Average phase differences obtained through PPI were virtually identical to those from fully Fourier encoded images.
• Phase noise in PPI acquisitions increased with g(sqrt)L, consistent with standard PPI behavior.

Conclusions:

• Partially parallel imaging offers a viable approach to increase temporal resolution in MR temperature imaging.
• This technique allows for reliable monitoring of thermal ablation therapies without compromising essential image quality metrics.
• PPI enhances MRTI's potential for real-time therapeutic guidance and improved patient safety.