SU-E-J-53: A Phantom Validation Study of a 3D Background Phase Model for MR Thermometry.

Area of Science:

• Medical Imaging
• Biophysics
• Therapeutic Monitoring

Background:

• Proton resonance frequency (PRF) shift is standard for magnetic resonance thermal imaging.
• PRF shift is sensitive to tissue motion and background noise due to phase map subtraction.
• Real-time monitoring of thermal therapies requires motion-robust imaging techniques.

Purpose of the Study:

• To develop a 3D background phase estimation method for magnetic resonance thermal imaging.
• To create a motion-artifact-resistant phase reference for improved thermal therapy monitoring.
• To enhance the accuracy and reliability of real-time temperature measurements during thermal therapies.

Main Methods:

• A 3D fast SPGR sequence was used with a magnetic resonance spectroscopy (MRS) phantom in a 3T MRI scanner.
• Phase images were acquired, and data was systematically removed to simulate heating regions and reduced data availability.
• A 3D finite element model solved the Dirichlet problem using boundary phase measurements.

Main Results:

• Phase estimates from the 3D method showed good agreement with actual phase measurements in phantom studies.
• Effective phase estimation was maintained even when data was reduced by excluding every other slice.
• The results demonstrate the feasibility of predicting background phase with incomplete data.

Conclusions:

• The proposed 3D multi-slice temperature estimation offers a robust alternative to the current PRF shift method.
• This technique is less susceptible to motion-induced artifacts compared to traditional PRF shift methods.
• The findings support the potential of this method for reliable real-time thermal therapy monitoring.