Cormack, Allan 1924–1998 Hounsfield, Godfrey Newbold 1919–

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Cormack, Allan
1924–1998
Hounsfield, Godfrey Newbold
1919–

Developers of Computer-Assisted Tomography

Allan McLeod Cormack and Godfrey Newbold Hounsfield won the Nobel Prize in physiology or medicine in 1979 for their work in the development of computer-assisted tomography (CAT).

Allan Cormack

Allan Cormack was born in Johannesburg, South Africa, in 1924. His parents had emigrated from Scotland to South Africa shortly before World War I (1914–1918); his father was a civil servant, who worked as an engineer for the post office. The family migrated through South Africa until 1936, when they settled in Cape Town after the death of Cormack's father. Cormack attended the Rondebosch Boys High School in Cape Town, and subsequently received both bachelor's and master's degrees in physics from the University of Cape Town. However, he initially studied electrical engineering in a department headed by B. L. Goodlet, who believed that engineers needed a good grounding in physics and math. Cormack was already interested in these subjects, having earlier studied astronomy, a field which requires a solid background in physics and math. Thus, he eventually abandoned engineering for physics.

After obtaining his degrees at Cape Town, he went to St. John's College, Cambridge, England, as a research student and worked in the Cavendish Laboratory under Professor Otto Frisch (1904–1979), a renowned physicist. Frisch, along with his aunt Lise Meitner, had performed fundamental work in the area of nuclear fission. Cormack later worked on problems connected with Helium-6 (He-6, Helium of atomic weight 6).

Cormack later married Barbara Seavey, an American, whom he had met at a quantum dynamics lecture. Cormack sought a teaching position in the physics department at the University of Cape Town. Offered a position as lecturer, Cormack returned to Cape Town with his wife in 1950. His first sabbatical, however, was spent at Harvard University, where he worked on the team connected with the Harvard Cyclotron . During his stay at Harvard, Cormack was offered a position in the physics department at Tufts University, which he accepted in 1957, remaining there for the duration of his career. Having officially retired in 1995, Cormack continued working at Tufts.

While in Cape Town in the 1950s, Cormack also served as a medical physicist in the department of radiology at Groote Schuur Hospital. It was there that he began to think about the possibility of using X rays for diagnostic purposes, particularly in the treatment of cancer patients. X rays are absorbed by dense material, such as bone, hence obscuring the view of the tissue in question. Reasoning that multiple X rays projected at different angles, but in a single plane, would yield a more detailed image, he developed a set of equations to describe the process. However, his findings, published in 1963 and 1964 in the Journal of Applied Physics, went largely unnoticed.

Godfrey Hounsfield

Godfrey Hounsfield was born on August 28, 1919, in Newark, Nottinghamshire, England, and raised on a farm. He attributed his interest in mechanical and electrical gadgets, especially experimentation, to his days and experiences on the farm, uncluttered by the distractions of a "larger" and "busier" civilization. He suggested that this was at the expense of his more formal schooling at Magnus Grammar School in Newark, where he claimed to respond only to math and physics with any "moderate" enthusiasm. He joined the Royal Air Force (RAF) as a volunteer reservist at the outbreak of World War II (1939–1945), and became interested in radio and then radar . He became a radar mechanic instructor and was moved to the Royal College of Science in South Kensington and then to the Cranwell Radar School.

After the war, one of his superiors, Air Vice-Marshall Cassidy obtained a grant for him to attend the Faraday House Electrical Engineering College in London, where Hounsfield earned a diploma. In 1951 Hounsfield joined the staff of EMI, Ltd., in Middlesex, England, where he worked on radar and guided weapons. He later became interested in computers, creating drums and tape decks from scratch, experimenting with core memory, and, in 1958, leading a design team to construct the first all-transistor computer built in Great Britain, the EMIDEC 1100.

When this work was finished, he transferred to EMI Central Research Laboratories in Hayes. It was there that he became interested in pattern recognition . Through this interest in pattern recognition, he happened upon the work that would eventually lead to computerized tomography.

Hounsfield got the initial idea in 1967, after which he carried on experimentation, finally developing and designing several prototypes , some of which went into production. EMI introduced the first commercial scanner in 1972. In this period, 1970 to 1972, Cormack became aware of the developments in CT-scanning and became, once again, more involved in these problems.

Both Cormack and Hounsfield developed interests in biology late in their careers. Cormack died in 1998; Hounsfield continued to work and live in Great Britain. The first heart transplant was performed at Groote Schuur Hospital by Dr. Christiaan Barnard in 1967. This is, of course, where Cormack worked. Cormack and Hounsfield had worked independently in the same area, and were both honored for the body of their work.

Hounsfield also won the Gardiner Foundation Award for achievement in biomedical research in 1976, and the Lasker Award for research in the biological sciences in 1975. He was knighted in 1981. The two scientists met for the first time in Stockholm, as Nobel Prize laureates.

see also Graphic Devices; Image Analysis: Medicine; Medical Systems.

Roger R. Flynn