Flexible add-on solution for MR image-guided interventions in a closed-bore scanner environment

Area of Science:

• Medical Imaging
• Surgical Navigation
• Biomedical Engineering

Background:

• Magnetic Resonance Imaging (MRI) is crucial for guiding diagnostic and therapeutic procedures.
• Standard MRI guidance can be time-consuming and inaccurate without navigational assistance.
• Existing methods often require repositioning patients for reference imaging.

Purpose of the Study:

• To develop and evaluate an add-on navigation solution for standard closed-bore MRI scanners.
• To overcome limitations of accuracy, time, and complexity in MRI-guided interventions.
• To provide real-time instrument tracking and visualization for improved procedural guidance.

Main Methods:

• An automated, robust, and rapid (<30 sec) localization of table-mounted MR reference markers for patient registration.
• Optical tracking of the surgical instrument.
• Real-time reconstruction of MR images for virtual instrument display and hand-eye coordination.
• Phantom studies to assess needle displacement accuracy.
• Clinical demonstration using a subscapular hook-wire insertion.

Main Results:

• Phantom studies showed needle displacement accuracy of 2.2 +/- 0.6 mm and 3.9 +/- 2.4 mm.
• Accuracy varied based on the distance of reference markers from the isocenter.
• Successful clinical demonstration of a complex hook-wire insertion in a patient with obesity (BMI 30.1 kg/m^2).

Conclusions:

• The developed add-on navigation system enhances MRI-guided procedures by improving accuracy and efficiency.
• The system's ease of use, compactness, and flexibility suggest broad applicability across various procedures and body regions.
• Further clinical evaluation with more patient cases is recommended to fully assess performance and workflow integration.