Open-Source Simulator of Imaging Near Metal at Arbitrary Magnetic Field Strengths

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Magnetic Resonance Imaging (MRI)

Background:

• Orthopedic metallic implants are increasingly common, requiring advanced MRI techniques for monitoring.
• Optimizing MRI protocols for mid- and low-field systems is crucial for imaging around metal implants.
• Existing methods face challenges in artifact reduction and image quality near metallic materials.

Purpose of the Study:

• To develop a simulation framework for predicting MRI performance near metallic orthopedic implants.
• To evaluate the impact of B0 field strength and multi-spectral imaging (MSI) parameters on imaging outcomes.
• To facilitate the optimization of MRI protocols for various field strengths and implant types.

Main Methods:

• Developed a simulation framework integrating 3D implant and anatomical models with imaging parameters.
• Simulated MSI acquisitions based on susceptibility-induced field shifts.
• Validated simulations against phantom and in vivo experiments at 0.55 T and 3 T, comparing artifact patterns and SNR.

Main Results:

• Simulations accurately reproduced experimental MRI performance, closely matching artifact shape and size at both 0.55 T and 3 T.
• The framework correctly predicted increased signal-to-noise ratio (SNR) and artifact size with higher field strengths.
• Demonstrated the influence of field strength, spectral bins, bandwidths, and implant materials on artifacts and image quality.

Conclusions:

• The developed open-source simulation framework reliably predicts MRI performance near metallic implants.
• This tool enables efficient protocol optimization and parameter exploration, reducing the need for costly experiments.
• Facilitates prediction of imaging performance across diverse implants and field strengths, accelerating clinical protocol development.