Comparison of Two and Three-Dimensional Optical Tomographic Image Reconstructions of Human Finger Joints

We have developed an image reconstruction algorithm to recover the spatial distribution of optical properties in human finger joints for early diagnosis and monitoring of rheumatoid arthritis (RA). An optimization method iteratively employs a light propagation model based on the equation of radiative transfer (ERT) for recovering the unknown absorption and scattering coefficients distribution for near-infrared (NIR) light inside the joint tissue. We explored the differences in cross-sectional images obtained by using the reconstruction algorithms with 2-dimensional and 3-dimensional light propagation models. In particular we examined how these different approaches affect the discrimination between healthy and RA joints.