1. Quantitation and mapping of tissue optical properties using modulated imaging
- Author
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David J. Cuccia, Anthony J. Durkin, Frédéric Bevilacqua, Bruce J. Tromberg, and Frederick Ayers
- Subjects
Materials science ,Diffuse reflectance infrared fourier transform ,Monte Carlo method ,Biomedical Engineering ,Models, Biological ,Sensitivity and Specificity ,Article ,Light scattering ,Biomaterials ,Optics ,Nephelometry and Turbidimetry ,Optical transfer function ,Image Interpretation, Computer-Assisted ,Humans ,Computer Simulation ,Image resolution ,Phantoms, Imaging ,business.industry ,Scattering ,Reproducibility of Results ,Image Enhancement ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Tomography ,Spatial frequency ,business ,Algorithms ,Tomography, Optical Coherence - Abstract
We describe the development of a rapid, noncontact imaging method, modulated imaging (MI), for quantitative, wide-field characterization of optical absorption and scattering properties of turbid media. MI utilizes principles of frequency-domain sampling and model-based analysis of the spatial modulation transfer function (s-MTF). We present and compare analytic diffusion and probabilistic Monte Carlo models of diffuse reflectance in the spatial frequency domain. Next, we perform MI measurements on tissue-simulating phantoms exhibiting a wide range of l*values (0.5mmto3mm) and (μs′/μa) ratios (8 to 500), reporting an overall accuracy of approximately 6% and 3% in absorption and reduced scattering parameters, respectively. Sampling of only two spatial frequencies, achieved with only three camera images, is found to be sufficient for accurate determination of the optical properties. We then perform MI measurements in an in vivo tissue system, demonstrating spatial mapping of the absorption and scattering optical contrast in a human forearm and dynamic measurements of a forearm during venous occlusion. Last, metrics of spatial resolution are assessed through both simulations and measurements of spatially heterogeneous phantoms. © 2009 Society of Photo-Optical Instrumentation Engineers.
- Published
- 2009