Straightforward Magnetic Resonance Temperature Measurements Combined with High Frame Rate and Magnetic Susceptibility...

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Biomedical Engineering
• Therapeutic Monitoring

Background:

• Proton Resonance Frequency Shift (PRFS) is a high-resolution MRI temperature mapping technique.
• Fiber-optic thermal sensors (FOSs) used for PRFS validation can introduce temperature errors due to magnetic susceptibility changes.
• Existing methods lack sufficient accuracy for precise thermal monitoring.

Purpose of the Study:

• To develop and validate a susceptibility-corrected PRFS (scPRFS) method for accurate, high-frame-rate temperature mapping.
• To address the limitations of conventional PRFS and FOS validation in MRI thermometry.
• To assess the potential of scPRFS for non-invasive thermal therapies.

Main Methods:

• Implemented a single-echo-based background removal technique for phase variation correction due to magnetic susceptibility.
• Developed scPRFS for fast, accurate temperature mapping.
• Validated scPRFS against FOSs using phantom and ex vivo experiments.

Main Results:

• scPRFS demonstrated good agreement with thermal sensor readings.
• Root mean square errors (RMSE) were 0.33-0.36 °C in phantom models and 0.12-0.16 °C in ex vivo experiments.
• Achieved high frame rate and accuracy in temperature measurements.

Conclusions:

• scPRFS provides precise thermal monitoring capabilities.
• The method is suitable for both low- and high-temperature non-invasive therapies.
• scPRFS shows significant potential for improving MRI-guided thermal ablation and monitoring.