A deflectable guiding catheter for real-time MRI-guided interventions.

Area of Science:

• Biomedical Engineering
• Medical Devices
• Interventional Radiology

Background:

• Interventional magnetic resonance imaging (MRI) requires specialized catheters.
• Existing catheters often contain long metallic components, posing risks during MRI.
• Developing MRI-compatible catheters with preserved mechanical integrity is crucial.

Purpose of the Study:

• To design a deflectable guiding catheter for interventional MRI.
• To minimize metallic components while maintaining essential mechanical properties.
• To facilitate therapeutic procedures under MRI guidance.

Main Methods:

• Incorporated Kevlar braiding and short nitinol components (slotted tube, spring).
• Developed passive, passive with inductive coil, and active receiver configurations.
• Evaluated mechanical properties, MRI compatibility, RF heating, and in vivo performance in swine.

Main Results:

• Satisfactory torque and tip deflection force achieved.
• Demonstrated successful procedures like hepatic/azygos vein access and septostomy.
• Active configuration provided superior visualization; passive designs usable with active guidewires.
• No significant RF-induced heating observed in vitro or in vivo.

Conclusions:

• Kevlar and short nitinol components effectively preserve mechanical properties.
• Active designs offer best visibility but reintroduce metal; passive designs are viable alternatives.
• Versatile deflectable guiding catheters (0.057" lumen) are feasible for interventional MRI using various visualization strategies.