Diffuse Optical Tomography: Current Status and Future Prospects

The diffuse optical tomography (DOT) technique reconstructs images of optical properties in biological tissue from boundary measurements. Even though its image quality remains far from clinical use, DOT has great potential for diagnostic optical imaging. Its image reconstruction algorithm basically consists of two parts: forward and inverse problems. The radiative transfer equation (RTE) accurately describes photon propagation in biological tissue. Because of its high computation load, the diffusion equation (DE) is often used as a forward model. However, the DE is invalid in the low-scattering and/or highly absorbing regions and near sources. The inverse problem is inherently ill-posed and highly undetermined. The uncertainty of the optical properties of biological tissue also complicates image reconstruction for DOT. Here, we first overview DOT and then describe our approaches for developing accurate and efficient DOT algorithms. Finally, we discuss its future prospects.