The effects of internal refractive index variation in near-infrared optical tomography: a finite element modelling approach
| Autor: | Ben Brooksby, Keith D. Paulsen, Hamid Dehghani, Brian W. Pogue, Karthik Vishwanath |
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| Rok vydání: | 2003 |
| Předmět: |
Materials science
Infrared Rays Finite Element Analysis Monte Carlo method Models Biological Sensitivity and Specificity Optics Image Interpretation Computer-Assisted medicine Scattering Radiation Tomography Optical Computer Simulation Radiology Nuclear Medicine and imaging Optical tomography Absorption (electromagnetic radiation) Models Statistical Spectroscopy Near-Infrared Radiological and Ultrasound Technology medicine.diagnostic_test Scattering business.industry Phase-contrast imaging Reproducibility of Results Finite element method Refractometry Tomography business Monte Carlo Method Refractive index |
| Zdroj: | Physics in Medicine and Biology. 48:2713-2727 |
| ISSN: | 1361-6560 0031-9155 |
| DOI: | 10.1088/0031-9155/48/16/310 |
| Popis: | Near-infrared (NIR) tomography is a technique used to measure light propagation through tissue and generate images of internal optical property distributions from boundary measurements. Most popular applications have concentrated on female breast imaging, neonatal and adult head imaging, as well as muscle and small animal studies. In most instances a highly scattering medium with a homogeneous refractive index is assumed throughout the imaging domain. Using these assumptions, it is possible to simplify the model to the diffusion approximation. However, biological tissue contains regions of varying optical absorption and scatter, as well as varying refractive index. In this work, we introduce an internal boundary constraint in the finite element method approach to modelling light propagation through tissue that accounts for regions of different refractive indices. We have compared the results to data from a Monte Carlo simulation and show that for a simple two-layered slab model of varying refractive index, the phase of the measured reflectance data is significantly altered by the variation in internal refractive index, whereas the amplitude data are affected only slightly. |
| Databáze: | OpenAIRE |
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