1. From the Department of Anesthesiology, University of Michigan, Ann Arbor, Mich (Z.R.M.); Department of Biomedical Engineering, Johns Hopkins University Whiting School of Engineering, Baltimore, Md (K.V., J.S.); and University of Maryland Medical Intelligent Imaging (UM2ii) Center, Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, 22 S Greene St, First Floor, Baltimore, MD 21201 (P.H.Y.).