This study aims at the design, implementation, and verification of a 
near infrared
(NIR) diffuse optical tomography (DOT) electro-optical imaging system based on a measuring instrument with single rotating source/detector scanning mechanism and an image reconstruction scheme implemented on an off-line PC. The developed measurement instrument possesses a high degree of angular resolution and is operated in a continuous-intensity scheme to acquire output NIR intensity signals. In this paper, some considerations of this measuring instrument are investigated such as phantom preparation, temporal stability, and container influence, etc. Experimental trials were conducted using both homogeneous and heterogeneous phantoms made of high-scattering microspheres or Intralipid.
In order to verify the developed imaging system with tomographic image reconstruction, the intensity was acquired from the heterogeneous Intralipid phantom using NIR light at 800 nm, where the homogenous background as the normal tissue is inserted with an inclusion as the tumor. For the comparison of heterogeneous phantoms with homogeneous phantoms, 1-D measured intensity signals indicate the angular position of the inclusion, especially for the case of the inclusion near the phantom boundary. Furthermore, promising results of corresponding optical-property images can be reconstructed with the measured intensities as inputs of the image reconstruction scheme. Obviously, the developed NIR DOT tomographic system has been successfully built upon the experimental, analytical, and computational work.
