1. From the Department of Radiology, Altman Clinical and Translational Research Institute, University of California, San Diego, 9452 Medical Center Dr, 4th Floor, La Jolla, CA 92037 (T.A.R., A.H.); Department of Bioengineering, University of California San Diego School of Medicine, La Jolla, Calif (E.M.M.); and Arterys, San Francisco, Calif (D.G.).