1. Experimental validation of a high-resolution diffuse optical imaging modality: photomagnetic imaging
- Author
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Gultekin Gulsen, Seunghoon Ha, Alex Luk, Dave Thayer, Yuting Lin, and Farouk Nouizi
- Subjects
Optics and Photonics ,Materials science ,Image Processing ,Multiphysics ,Research Papers: Imaging ,image reconstruction techniques ,Biomedical Engineering ,Bioengineering ,Optical Physics ,Models, Biological ,01 natural sciences ,Temperature measurement ,Phantoms ,Imaging ,030218 nuclear medicine & medical imaging ,law.invention ,010309 optics ,Biomaterials ,Magnetics ,03 medical and health sciences ,Computer-Assisted ,0302 clinical medicine ,Optics ,Models ,Opthalmology and Optometry ,law ,0103 physical sciences ,Image Processing, Computer-Assisted ,medical and biological imaging ,Absorption (electromagnetic radiation) ,Phantoms, Imaging ,inverse problems ,business.industry ,Optical Imaging ,Reproducibility of Results ,Reconstruction algorithm ,Biological ,Laser ,Atomic and Molecular Physics, and Optics ,Diffuse optical imaging ,Electronic, Optical and Magnetic Materials ,Signal-to-noise ratio (imaging) ,Attenuation coefficient ,Biomedical Imaging ,business ,Algorithms ,light propagation in tissues - Abstract
We present experimental results that validate our imaging technique termed photomagnetic imaging (PMI). PMI illuminates the medium under investigation with a near-infrared light and measures the induced temperature increase using magnetic resonance imaging. A multiphysics solver combining light and heat propagation is used to model spatiotemporal distribution of temperature increase. Furthermore, a dedicated PMI reconstruction algorithm has been developed to reveal high-resolution optical absorption maps from temperature measurements. Being able to perform measurements at any point within the medium, PMI overcomes the limitations of conventional diffuse optical imaging. We present experimental results obtained on agarose phantoms mimicking biological tissue with inclusions having either different sizes or absorption contrasts, located at various depths. The reconstructed images show that PMI can successfully resolve these inclusions with high resolution and recover their absorption coefficient with high-quantitative accuracy. Even a 1-mm inclusion located 6-mm deep is recovered successfully and its absorption coefficient is underestimated by only 32%. The improved PMI system presented here successfully operates under the maximum skin exposure limits defined by the American National Standards Institute, which opens up the exciting possibility of its future clinical use for diagnostic purposes.
- Published
- 2016