1. From the Department of Biomedical Engineering (C.S., B.B.L., A.R., Q.H.), the Department of Radiology (B.B.L.), and the Endovascular Research Center, Vascular Biology Institute (L.C.), University of Miami, Coral Gables, Fla; the Department of Engineering and Physics (J.S.), University of Central Oklahoma, Edmond; the Department of Radiology (A.K.W.), University of Massachusetts Medical School, Worcester; and the Department of Medicine (F.O.T.), University of Texas Health Science Center, San Antonio.