Integrated active tracking detector for MRI-guided interventions.

Area of Science:

• Medical Imaging
• Microsystems Engineering
• Biomedical Engineering

Background:

• Magnetic Resonance Imaging (MRI) guided interventions require precise tracking of interventional devices.
• Existing tracking methods may have limitations in terms of accuracy, integration, or compatibility with MRI environments.

Purpose of the Study:

• To develop and evaluate a fully integrated detector for active tracking of interventional devices within MRI scanners.
• To demonstrate the feasibility of using a single-chip microsystem for real-time spatial localization during interventions.

Main Methods:

• A single-chip complementary metal-oxide-semiconductor (CMOS) microsystem was designed and fabricated, integrating a detection coil, tuning capacitor, and signal processing components.
• The microchip incorporates an intermediate frequency (IF) downconversion receiver and a phase-locked-loop (PLL) frequency synthesizer.
• The system operates at 63 MHz (compatible with 1.5 T clinical MRI scanners) and outputs an analog NMR signal between 0-200 kHz.

Main Results:

• The fabricated CMOS microchip measures 1 × 2 × 0.74 mm(3).
• Tests confirmed compatibility with standard clinical MRI systems.
• Using a 1 × 1.9 × 0.8 mm(3) cis-polyisoprene sample, a 3D isotropic spatial resolution of 0.15 mm was achieved in 100 ms.

Conclusions:

• The developed integrated detector is suitable for active tracking of interventional devices in MR-guided interventions.
• The CMOS microchip offers high spatial resolution and compatibility with clinical MRI, paving the way for improved image-guided therapies.