Diffuse optical localization of blood vessels and 3D printing for guiding oral surgery.

Diffuse optical imaging through centimeters of tissue has emerged as a powerful tool in biomedical research. However, applications in the operating theater have been limited in part due to data set requirements and computational burden. We present an approach that uses a small number of optical source-detector pairs that allows for the fast localization of arteries in the roof of the mouth and has the potential to reduce complications during oral surgery.

In vivo mouse fluorescence imaging for folate-targeted delivery and release kinetics.

Many cancer cells over-express folate receptors, and this provides an opportunity for both folate-targeted fluorescence imaging and the development of targeted anti-cancer drugs. We present an optical imaging modality that allows for the monitoring and evaluation of drug delivery and release through disulfide bond reduction inside a tumor in vivo for the first time. A near-infrared folate-targeting fluorophore pair was synthesized and used to image a xenograft tumor grown from KB cells in a live mouse.

Prediction of electric field frequency correlations for randomly scattering slabs in the nondiffusive regime with the scalar Bethe-Salpeter equation.

We show that a scalar Bethe-Salpeter equation model captures the measured copolarized electric field frequency correlation magnitude for randomly scattering slabs in the weakly scattering, nondiffusive regime. Consequently, the model could be used to form images of tissue on the millimeter and submillimeter length scale, and for environmental sensing with comparable scatter, as dictated by the optical scattering length in relation to the scattering domain size.

Small animal optical diffusion tomography with targeted fluorescence.

Despite the broad impact in medicine that optics can bring, thus far practical approaches are limited to weak scatter or near-surface monitoring. We show a method that utilizes a laser topography scan and a diffusion equation model to describe the photon transport, together with a multiresolution unstructured grid solution to the nonlinear optimization measurement functional, that overcomes these limitations. We conclude that it is possible to achieve whole body optical imaging with a resolution suitable for finding cancer nodules within an organ during surgery, with the aid of a targeted imaging agent.

Deep-tissue imaging of intramolecular fluorescence resonance energy-transfer parameters.

We demonstrate the in vivo reconstruction of all fluorescence resonance energy transfer (FRET) parameters, including the nanometer donor-acceptor distance, in a mouse. The FRET chemical targets cancer cells, and on internalization, the acceptor is released, in lieu of a targeted anticancer drug in chemotherapy. Our method provides a new vehicle for studying disease by imaging FRET parameters in deep tissue.

Towards in vivo imaging of intramolecular fluorescence resonance energy transfer parameters.

Fluorescence resonance energy transfer (FRET) is a nonradiative energy transfer process based on dipole-dipole interaction between donor and acceptor fluorophores that are spatially separated by a distance of a few nanometers. FRET has proved to be of immense value in the study of cellular function and the underlying cause of disease due to, for example, protein misfolding (of consequence in Alzheimer's disease). The standard parameterization in intramolecular FRET is the lifetime and yield, which can be related to the donor-acceptor (DA) distance.

Localization of an absorbing inhomogeneity in a scattering medium in a statistical framework.

An approach for the fast localization and detection of an absorbing inhomogeneity in a tissuelike scattering medium is presented. The probability of detection as a function of the size, location, and absorptive properties of the inhomogeneity is investigated. The detection sensitivity in relation to the source and detector location serves as a basis for instrument design.