2023-present, Professor, Department of Diagnostic Radiology, City of Hope, Duarte, CA
2013-present, President, City of Hope Medical Group
2011-2023, Professor and Chair, Department of Diagnostic Radiology, City of Hope, Duarte, CA
2016-2017, Interim Chief Medical Officer, City of Hope, Duarte, CA
2007-2011, Professor of Clinical Radiology and Urology, University of Southern California (USC) School of Medicine, Los Angeles, CA
1983-2011, Chief, Diagnostic Radiology, USC Norris Cancer Hospital, Los Angeles, CA
1996-2011, Associate Chairman, Department of Radiology, USC School of Medicine, Los Angeles, CA
2006-2007, Associate Professor of Urology, USC School of Medicine, Los Angeles, CA
1984-2007, Associate Professor of Clinical Radiology, USC School of Medicine, Los Angeles, CA
1979-1998, Chief, Diagnostic Radiology, Los Angeles County+USC Medical Center, Los Angeles, CA
1989-1996, Executive Vice Chairman, Department of Radiology, USC School of Medicine, Los Angeles, CA
1982-1989, Vice Chairman, Department of Radiology, USC School of Medicine, Los Angeles, CA
1979-1985, Chief of Cross Sectional Imaging, Los Angeles County+USC Medical Center, Los Angeles, CA
1977-1984, Assistant Professor of Radiology, USC School of Medicine, Los Angeles, CA
1976-1977, Clinical Instructor of Radiology, Supervisor of Residents, USC School of Medicine, Los Angeles, CA