Metallic implant geometry and susceptibility estimation using multispectral B0 field maps.
Xinwei Shi1,2, Daehyun Yoon1, Kevin M Koch3
1Department of Radiology, Stanford University, Stanford, California, USA.
Magnetic Resonance in Medicine
|July 8, 2016
Summary
This study introduces a new method using multispectral imaging (MSI) to accurately estimate metallic implant susceptibility and geometry. The technique effectively distinguishes metal implants from surrounding tissues in medical scans.
Area of Science:
- Medical Imaging
- Biomedical Engineering
- Materials Science
Background:
- Metallic implants in medical imaging can cause signal loss and artifacts.
- Accurate characterization of implant susceptibility and geometry is crucial for image interpretation and analysis.
Purpose of the Study:
- To estimate the susceptibility and geometry of metallic implants using multispectral imaging (MSI).
- To differentiate metal implant regions from surrounding signal loss areas.
Main Methods:
- Utilized multispectral imaging (MSI) B0 field maps for susceptibility estimation.
- Employed total variation (TV) regularized inversion to create susceptibility maps.
- Identified metal voxels based on susceptibility estimates exceeding a threshold.
Main Results:
- The proposed method showed improved susceptibility estimation accuracy compared to non-TV regularized methods.
- Phantom experiments achieved 85% precision and 93% recall for implant geometry.
- In vivo studies successfully distinguished hip implants from low-signal tissues like cortical bone.
Conclusions:
- The developed method enhances metallic implant geometry delineation.
- Distinguishes metal from signal voids and low-signal tissues by estimating susceptibility maps.


