Interventional MR elastography for MRI-guided percutaneous procedures.

Area of Science:

• Medical Imaging
• Biophysics
• Interventional Radiology

Background:

• MRI-guided thermal ablations necessitate precise monitoring to confirm diseased tissue destruction and prevent collateral damage to healthy tissues.
• Thermal ablation procedures induce significant alterations in tissue biomechanical properties, creating an opportunity for monitoring.

Purpose of the Study:

• To introduce and evaluate interventional MR elastography (MRE) as a method for monitoring MRI-guided thermal therapies.
• To assess the real-time capability of MRE in tracking elasticity changes during thermal ablation.

Main Methods:

• Development of an interventional MRE protocol including a needle MRE driver, fast gradient echo pulse sequence with motion encoding, and a real-time inverse problem solver.
• In vivo testing on swine and phantom studies to evaluate real-time elasticity monitoring.

Main Results:

• Achieved an elastogram refresh rate of 2.56 seconds at 100 Hz excitation frequency through optimized sequence parameters.
• Successfully generated real-time in vivo elastograms of swine liver during a single breath-hold.
• Demonstrated real-time monitoring of elasticity changes in a phantom during gelation.

Conclusions:

• Interventional MRE can effectively detect elasticity changes in real-time.
• The developed MRE technique shows promise for in vivo monitoring of thermal ablations.