CT imaging of diffuse medium by time-resolved measurement of backscattered light.

Backscattered light was used to reconstruct cross-sectional images of absorption distributions in diffuse media. For efficient and accurate reconstruction, the inverse problem was solved for one dimension, thereby yielding the absorption distribution in a depth direction. A cross-sectional image or three-dimensional structure is reconstructed by shifting a source-detector pair along the object surface. The object is divided into imaginary layers to solve the inverse problem. This solution's accuracy is further improved by solving the problem for two groups of layers successively instead of solving for all layers simultaneously. The technique's effectiveness was verified using solid phantoms and biological tissues.