Objectives: Accurate needle guidance is essential for a number of MRI-guided percutaneous procedures, such as radiofrequency ablation (RFA) of metastatic liver tumors. A promising technology to obtain real-time tracking of the shape and tip of a needle is by using high frequency (up to 20 kHz) fiber Bragg grating (FBG) sensors embedded in optical fibers, which are insensitive to external magnetic fields.
Methods: We fabricated an MR-compatible needle designed for percutaneous procedures with a series of FBG sensors which would be tracked in an image-guidance system, allowing to display the needle shape within a navigation image.
Results: A series of phantom experiments demonstrated needle tip tracking errors of 1.05 ± 0.08 mm for a needle deflection up to 16.82 mm on a ground-truth model and shown nearly similar accuracy to electromagnetic tracking (i.e. 0.89 ± 0.09 mm).
Conclusion: We demonstrated feasibility of the FBG-based tracking system for MR guided interventions with differences under 1 mm between tracking systems.
Significance: This study establishes the needle tracking accuracy of FBG needle tracking for image-guided procedures.