Accomplishments

Diffuse Optics: Technological Research and Development

• A spatially-modulated imaging (MI) system was developed based on diffusely-reflected structured light for quantitatively mapping tissue absorption and scattering properties and forming depth-sectioned images in thick tissue. (D. Cuccia et al., 2005, 2006, 2007)
• The MI method was extended to diffusely remitted fluorescence for imaging subsurface fluorophores and determining fluorescence quantum yield in tissues. (A. Mazhar et al., 2007)
• Spatially-modulated imaging was integrated with computed tomography imaging spectroscopy (CTIS) to achieve fast hyperspectral images of absorption and scattering in turbid systems. (J. Weber et al., 2007)
• A new fiber probe was developed to measure absorption and scattering spectra in defined, superficial tissue volumes (<mm depth) using broadband diffuse optical spectroscopy (DOS) and a probe tip assembly that incorporates an integrated diffusing layer. (S. Tseng et al., 2005, 2006)
• A multi-frequency, multi-spectral, multi-position model was developed and experimentally validated for acquiring broadband absorption and scattering spectra from 2 independent layers of cm-thick tissues. (A. Li et al., in press)

Characterizing optical properties of polysiloxane tissue phantom using broadband DOS fiber probes.

• An integrated DOS/MRI system was developed for simultaneous, co-registered imaging of tissue structure and biochemical composition in an animal tumor model in vivo. (S. Merritt et al., 2003)
• Quantitative DOS water and lipid measurements were validated by developing specialized lipid emulsion phantoms and performing co-registered, quantitative analyses with MRI. (S. Merritt et al., 2003)
• Broadband DOS spectral analysis tools were developed for evaluating the relative disposition of water (i.e. bound and free states) in tissue and determining subsurface temperature from water spectral shifts. (S. Meritt, 2005, S. Chung et al., 2007)
• A diffusion approximation (d-P1) was used to demonstrate the accurate recovery of optical properties in the transport regime. (C. Hayakawa et al., 2004)
• Ballistic, transport and diffusive regimes of light propagation in tissue were defined within a transport-rigorous context. (J. You et al., 2005)
• Experimental validation of the application the pMC/dMC model was achieved for measurement of layered tissue optical properties in the transport regime. (I-S Seo et al., 2007)
• Frequency-dependent difference in phase and amplitude sensitivity were shown by reconstructing and visualizing spatial sensitivity maps in frequency-domain photon migration. (F. Bevliacqua et al., 2004)