Volumetric thermometry in moving tissues using stack-of-radial MRI and an image-navigated multi-baseline proton...

Area of Science:

• Medical Imaging
• Thermometry
• Interventional Radiology

Background:

• Accurate temperature monitoring is crucial for effective thermal ablation.
• Motion in tissues poses a significant challenge for real-time temperature mapping during MRI-guided procedures.

Purpose of the Study:

• To develop and evaluate a volumetric proton resonance frequency shift (PRF)-based thermometry method.
• To enable accurate thermal ablation monitoring in moving tissues using MRI.

Main Methods:

• A 3D stack-of-radial MRI sequence combined with an image-navigated multi-baseline (iNAV-MB) PRF method was used.
• Two reconstruction techniques, KWIC and GRASP MRI, were compared for motion-compensated 3D temperature mapping.
• Ex vivo and in vivo experiments were conducted using motion phantoms and swine models.

Main Results:

• The iNAV-MB thermometry achieved high spatiotemporal resolution and volumetric coverage.
• Motion tracking showed high correlation coefficients (0.951-0.973) with low mean absolute errors (1.44-1.80°C).
• In vivo experiments demonstrated significant improvement in temperature mapping stability compared to single-baseline PRF.

Conclusions:

• The proposed stack-of-radial iNAV-MB volumetric PRF thermometry reliably tracks motion and maps ablation temperatures.
• This framework enhances MRI-guided thermal ablation in moving tissues.
• The method shows potential for improved clinical outcomes in thermal therapies.