1. Department of Surgery, University of Pittsburgh Medical Center, PA (L.T., B.X., E.A., R.F., R.I.M.A., U.S.).
2. University of Nebraska Medical Center Department of Surgery and the VA Research Service, VA Nebraska-Western Iowa Health Care System (I.I.P., G.P.C.).
3. University of Pittsburgh Center for Biologic Imaging, PA (S.W.).