1. From the Department of Radiology, University of Calgary Cumming School of Medicine, 1403 29 St NW, Calgary, AB, Canada T2N 2T9 (D.P.B., A.M., S.R.W.); Department of Radiology, University of California, San Diego, San Diego, Calif (Y.K.); and Department of Diagnostic Imaging, Foothills Medical Centre, Calgary, Alberta, Canada (S.R.W.).