| dc.description.abstract | Near infrared (NIR) diffuse optical tomography (DOT) is a new medical imaging modality, the advantages are safe (longer wavelength) and non-radioactive, in spite of its low spatial resolution at the current phase. Due to the diagnostic potential of NIR,the abnormality of tissues in NIR light is to allow earlier detection rather than most other imaging modalities. This thesis describes the NIR Electro-optical measurement for Intralipid phantoms using our own developed NIR DOT scanning
instrument with highly spatially angular resolution, in order to investigate the
influence of different factors such as the off-boundary, the volume density (v.d.) of
inclusion, and the size ratio. The influence of each condition also can reveal the real
condition of biomedical tissue, and this information can offer the doctor for diagnosis.
This thesis discusses Intralipid phantoms which are the homogeneous background
with one inclusion or two inclusions.
For the homogeneous background with one inclusion and the source position at s0 , the contrast is large, the resolution of inclusion position is good but the resolution of inclusion size is bad. The off-boundary is small, the resolution of contrast and inclusion size are both good. The inclusion size is large, the resolution of contrast is good but the resolution of off-boundary is bad.
For the homogeneous background with two inclusions and the source position at s0 , the contrast (I0) is large; the resolution of inclusion position is good. The off-boundary (I0) is small confined to the non-directly detected inclusion (I4) with small v.d.; the resolution of contrast is good. The common conclusion for the homogeneous background with one inclusion and two inclusions can be obtained.
Those phenomena are similar in some condition, especially for source position at s0 and Sπ.
This thesis also simulates a power curve by using an exponential form. The light trajectory of model in this thesis was set as straight line, unlike the real trajectory. The outcome does not seem well. From this thesis, it can give a general concept about the influence of different factors. Furthermore, the original experimental data can be used as the input and the calibration of image reconstruction. | en_US |