1930
Born to Florence Gerald Johnston and Lorna Freda Johnston in Johnstown, Pennsylvania.
1952
Earns a Bachelor of Science from the University of Pittsburgh.
1955
Serves as a commissioned medical officer for the U.S. Army until 1971.
1956
Earns a Doctor of Medicine from the University of Pittsburgh.
1956
Works as an intern at the Walter Reed General Hospital in Washington, D.C.
1956
Marries Dorothy Anna Jones.
1958
Serves as a resident in internal medicine at Brooke General Hospital in San Antonio, California.
1961
Works as a surgeon at the 358 General Dispensary in Seoul, Republic of Korea.
1963
Becomes the chief of nuclear medicine at the Walter Reed General Hospital in Washington, D.C.
1969
Becomes the chief of nuclear medicine at the Letterman General Hospital in San Francisco, California.
1970
Earns a Legion of Merit.
1971
Becomes a colonel within the U.S. Army.
1971
Serves as a captain within the U.S. Public Health Service until 1982.
1971
Works as the chief of nuclear medicine at the National Institutes of Health in Bethesda, Maryland.
1982
Works as the chief of nuclear medicine at the University of Maryland.
1982
Teaches as a professor of medicine, radiology and oncology at the University of Maryland.
1989
Becomes the acting chairman of the department of radiology at the University of Maryland.
1993
Becomes the chairman of the department of nuclear medicine at the Washington Hospital Center.
1999
Finds of the Nuclear Medicine Service at the Royal Hobart Hospital in Tasmania, Australia.
1999
Works as a staff nuclear medical physician at the Washington Hospital Center.