Noninvasive measurement and imaging of tissue structure and oxygenation using infrared time-of-flight absorbance (TOFA) spectrophotometry

Advances in the ability to produce and process near-infrared (NIR) light for in vivo analysis has led to an explosion in the number of techniques holding promise in the early detection and diagnosis of metabolic and structural problems. Using a picosecond time-of-flight and absorbance (TOFA) near-infrared multi-wavelength spectrophotometer, we have been studying optical-based imaging and quantitation. We have imaged the interior of scattering bodies, and produced images of whole animals in which major organs are visible. In humans, we are using a similar approach to locate and define intracranial bleeding in critically il infants. We have measured the resolving power of such a system to be better than 7 mm in infant brain, and 3mm in adult breast. We are investigating approaches to measure cerebral blood volume, cerebral blood flow, and arterial and venous saturation,. parameters useful in the detection and treatment of diseases related to problems in the delivery of oxygen to tissue. Combination of an imaging and quantitation approaches may yield additional information,. by allowing regional problems to be identified spatially, and this may result in improved treatment. As a result, the health-saving and life-saving potential of NIR optical imaging and quantitation is great.