Current assessment of organ tissue viability by surgeons in the operating room is limited to crude estimates such as overt physical examination, measurement of laboratory values and physical measurements of vascular flow and resistance. The ability to non-invasively measure tissue perfusion and oxygenation would provide the surgeon an improved means to assess if an injured organ will survive. The recent development of real time infrared (IR) and Near Infrared Imaging Spectroscopy (NIRIS) digital cameras has allowed for the determination of tissue perfusion and oxygenation in a non-invasive fashion. Although in the early stages of development, the application of infrared and NIRS technology holds great promise to permit the surgeon to better assess the viability of tissues in ways that have not been possible. We propose to evaluate infrared and NIRS technology in the assessment of kidney allografts using data previously collected during recipient operations at the NIH.