Comparative investigation into the influence on the measured radiance due to inclusion location, size and contrast for nir diffuse optical imaging system

As known, a phantom is designed for the use of measurement with a near-infrared diffuse optical imaging (NIR DOI) system; usually, such a phantom is made of a homogenous background incorporated with one or several inclusions. This study is an attempt to investigate the influences on the measured radiances due to inclusion location, size, and contrast. Various Intralipid phantoms were fabricated for the measurement through using our self-built scanning instrument with high angular resolution, where different factors were considered such as the offcenter distance (10, 20, and 30 mm), the size ratio (10, 20, and 30: 100), and the contrast (2, 3, and 4: 1) of an inclusion to the background. Finally, three measures/criteria, attenuation depth, width and measurement resolution, are defined to describe such influence on the measured radiances as well as we seek to find their regularity. In the study, experimental results were validated with numerical simulation as well. With this investigation, it can further deduce criteria to judge the limit on the measurement and differentiation of varied inclusion conditions for an NIR DOI measurement system.