Quantifying optical properties in small animals using MR-guided multispectral time-resolved imaging

We propose the use of Time-Resolved Diffuse Optical Tomography in a multispectral scheme with anatomical constraints supplied by MR imaging to reconstruct functional parameters of the animal model with greater accuracy and resolution. The tomographic imaging system described is capable of acquiring temporal measurements in multiple-views using a gated ICCD camera. A tunable Ti-Sapphire pulsed laser at wavelengths between 700nm - 1000nm is used as the source. Anatomical distribution is determined using MRI in a non-concurrent setting. Time-resolved measurements at multiple wavelengths in the NIR window combined with the anatomical constraints is used to determine a 3D distribution of the functional parameters in vivo. Multispectral spectroscopy measurements on homogenous tissue simulating phantoms are used to demonstrate the accuracy of the system in determining optical parameters in thin tissues. We show that temporal measurements combined with MRI data can be used to accurately quantify optical properties in heterogeneous tissues.