Targeted-HASTE imaging with automated device tracking for MR-guided needle interventions in closed-bore MR systems

Area of Science:

• Magnetic Resonance Imaging
• Medical Interventions
• Biomedical Engineering

Background:

• Percutaneous MR-guided interventions necessitate rapid imaging sequences to visualize needle trajectories accurately.
• Minimizing susceptibility artifacts is crucial for effective real-time guidance during interventions.
• Existing fast imaging techniques like RARE and HASTE face challenges in achieving sufficient speed and artifact reduction.

Purpose of the Study:

• To develop an advanced Half-Fourier Acquisition Single-shot Turbo Spin-Echo (HASTE) pulse sequence for enhanced MR-guided interventions.
• To reduce scan time and focus imaging on the needle trajectory using inner-volume excitation (targeted-HASTE).
• To improve needle localization accuracy and real-time visualization during percutaneous procedures.

Main Methods:

• Implementation of a targeted-HASTE pulse sequence with inner-volume excitation to limit the field of view (FOV).
• Integration of a magnetization restore pulse (driven equilibrium Fourier transform (DEFT)) to counteract signal saturation.
• Combination with active marker coils for automated repositioning of the targeted-HASTE slice based on needle position and orientation.
• Utilizing an MR-compatible robotic assistance system for interventional procedures in animal experiments.

Main Results:

• Demonstrated visualization of needle insertion and infusion with a temporal resolution of 1 second.
• Successful localization of the needle tip, even in the presence of a stainless steel mandrel, indicating robustness to artifacts.
• Validation of the targeted-HASTE sequence and active marker coil system in an animal model.

Conclusions:

• The developed targeted-HASTE sequence significantly enhances real-time visualization for MR-guided interventions.
• The system allows for precise needle guidance and localization, improving procedural accuracy and safety.
• This technique shows promise for various percutaneous interventions requiring high temporal and spatial resolution under MRI guidance.