1 From the Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, 1161 21st Ave S, CCC-1118 MCN, Nashville, TN 37232-2675 (C.M.T.); Department of Surgery, Washington University School of Medicine, St Louis, Mo (S.J.); and Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC (P.M.B.).