1. From the University of Colorado Denver, Denver, Colo (D.S.B); Department of Medical Imaging, Kaiser Permanente Colorado, Denver, Colo (D.S.B., K.H); Department of Medical Imaging (R.E.S., E.K.B.) and Departments of Internal Medicine and Geriatrics (W.S.G.), Colorado Permanente Medical Group, Denver, Colo; and Department of Radiology, Mayo Clinic, 5881 E Mayo Blvd, Phoenix, AZ 85054 (R.E.S.).