In vivo safe catheter visualization and slice tracking using an optically detunable resonant marker

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Interventional Cardiology

Background:

• Real-time magnetic resonance (MR) imaging enables image-guided interventions.
• Accurate catheter tracking is crucial for minimally invasive procedures.
• Existing tracking methods face limitations in precision and safety.

Purpose of the Study:

• To evaluate the in vivo feasibility of a novel catheter tracking system.
• To assess the safety and compatibility of an optically detunable resonant marker with guidewire materials.
• To test the system's performance in real-time MR-guided catheterizations.

Main Methods:

• Developed and integrated an optically detunable resonant marker into a catheter tip.
• Utilized real-time MR imaging with a radial steady-state free-precession sequence.
• Implemented automatic slice tracking via projection difference measurement and marker detuning.
• Conducted in vitro RF-safety tests and assessed guidewire interference.

Main Results:

• The resonant marker provided excellent in vivo contrast in swine aorta, left ventricle, and carotid arteries.
• Repetitive marker detuning (flashing) significantly improved in-plane visualization.
• Automatic slice tracking was successfully achieved during real-time imaging.
• Plastic guidewires showed no interference; nitinol guidewire effects were compensated.

Conclusions:

• The developed system enables safe, automatic catheter slice tracking and superior in-plane visualization.
• The approach is compatible with various guidewire materials and safe regarding RF transmission.
• This technology holds promise for enhancing MR-guided interventional procedures.