We demonstrate the use of diffuse optical imaging via transillumination to detect cancerous tissue in a rat animal model. In this imaging modality infrared radiation is transmitted through whole animal tissue. The radiation is nonionizing and uses endogenous contrast: namely deoxyhemoglobin (Hb) and oxyhemoglobin (HbO). Differential image analysis is performed to visualize the presence of cancerous tissue. Varying levels of inspired air and carbogen gases ensure a differential response in absorption by blood due to changing levels of Hb and HbO. We believe that this response may be sufficient to provide contrast in differential image analysis. The present method also sheds light on physiological challenges in whole animal imaging especially with respect to significant optical signals from healthy tissue. Specifically, we have seen strong signals from abdominal regions in normal rats indicative of diet related anomalous transmission. We have also been able to track the changes in optical signal during animal death.

Date Published: 13 February 2007
PDF: 5 pages
Proc. SPIE 6434, Optical Tomography and Spectroscopy of Tissue VII, 64341S (13 February 2007); doi: 10.1117/12.707907

Published in SPIE Proceedings Vol. 6434:
Optical Tomography and Spectroscopy of Tissue VII
Britton Chance; Robert R. Alfano; Bruce J. Tromberg; Mamoru Tamura; Eva Marie Sevick-Muraca, Editor(s)