 Given the difficulty of early detection of venous thrombosis, and of the decreased rates of successful salvage after surgical re-exploration for venous thrombosis, authors have employed successfully the use of tissue spectroscopy to detect venous thrombosis several hours before the clinical manifestations of thrombosis 2. These authors employed a spectroscopy device, which requires direct contact with the tissues being evaluated and only provided a small surface area in which the tissue flaps optical properties were measured. The device, however, is able to provide both diffuse optical tomography and rapid wide-field quantitative mapping of the tissues optical properties in a single measurement platform through a device that does not require direct contact with the tissues being evaluated 3, 11. As theMI device is a new novel device developed at the Beckman laser Institute and has not been used to evaluate human tissue transfer flaps this would be a pilot study. This pilot study would seek to determine if this specific device is also able to detect vascular occlusion prior to clinical detection of such occlusion, as well as to differentiate between arterial and venous occlusions in a similar manner to other devices used by other authors, which employed tissue spectroscopy to monitor tissue transfer flaps. 