1. From the Department of Radiology, Penn State Milton S. Hershey Medical Center and Penn State College of Medicine, 500 University Dr, H-066, Hershey, PA 17033 (M.A.B.); Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Mo (J.R.D., A.J.B.); and Department of Radiology, Wake Forest University Baptist Medical Center, Winston-Salem, NC (R.T.).