1. From the Department of Biomedical Engineering (B.A., L.E.S., G.J., D.J.D., B.P.R., D.J.E., V.L.M.), Vanderbilt University; and Vanderbilt University Institute of Imaging Science (B.A., L.E.S., A.J., G.J., D.J.D., B.P.R., D.J.E., V.L.M.), Department of Radiology and Radiological Sciences, and Department of Neurological Surgery (D.J.E., V.L.M.), Vanderbilt University Medical Center, Nashville, TN.