Active Electromagnetic Interference Suppression for MRI and Proton Resonance Frequency Shift Thermometry During...

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Electromagnetics

Background:

• MRI-guided microwave ablation (MWA) is a promising minimally invasive treatment.
• Electromagnetic interference (EMI) from ablation devices degrades MRI quality and hinders real-time monitoring.
• Reliable MRI and MR thermometry are crucial for effective MWA guidance.

Purpose of the Study:

• To develop and evaluate a software-based active electromagnetic interference (EMI) suppression (AES) framework.
• To enable reliable MRI and MR thermometry during MRI-guided MWA on whole-body multi-channel MRI systems.

Main Methods:

• Utilized auxiliary coils to detect and characterize EMI patterns.
• Applied principal component analysis to extract dominant EMI.
• Modeled and subtracted EMI from primary coil data using impulse response functions.
• Validated the framework in gel phantoms and in vivo pig models at 3T.

Main Results:

• AES achieved >92% EMI suppression, significantly improving image quality.
• Demonstrated 40-fold (gel) and 13-fold (in vivo) signal-to-noise ratio enhancement.
• Enabled reliable MR thermometry with low mean absolute error (<1.4°C in ablated regions).

Conclusions:

• The AES framework effectively suppresses MWA-related EMI, enhancing MRI and MR thermometry.
• This technology facilitates the clinical adoption of MRI-guided MWA.
• The approach is adaptable for other EMI-affected interventions.