Godfrey Hounsfield

Sir Godfrey Hounsfield (born 1919) won the Nobel Prize for medicine for co-inventing the CAT-scan (computer assisted tomography).

Sir Godfrey Hounsfield pioneered a great leap forward in medical diagnosis: computerized axial tomography, popularly known as the "CAT scan." Ushering in a new and sometimes controversial era of medical technology, Hounsfield's device allowed a doctor to look inside a patient's body and examine a three-dimensional image far more detailed than a conventional X ray. The importance of this advance was recognized in 1979, the year Hounsfield received the Nobel Prize for physiology or medicine.

Godfrey Newbold Hounsfield was born August 28, 1919, in Newark, England, the youngest of five children of a steel-industry engineer turned farmer. Hounsfield's technical interests began when, to prevent boredom, he began figuring out how the machinery on his father's farm worked. From there he moved on to exploring electronics, and by his teens was building his own radio sets. He graduated from London's City and Guilds College in 1938 after studying radio communication. When World War II erupted, Hounsfield volunteered for the Royal Air Force, where he studied and later lectured on the new and vital technology of radar at the RAF's Cranwell Radar School. After the war he resumed his education, and received a degree in electrical and mechanical engineering from Faraday House Electrical Engineering College in 1951. Upon graduation, Hounsfield joined Thorn EMI (Electrical and Musical Industries) Ltd., an employer he has remained with his entire professional life.

At Thorn EMI, Hounsfield worked on improving radar systems and then on computers. In 1959, a design team led by Hounsfield finished production of Britain's first large all-transistor computer, the EMIDEC 1100. Hounsfield moved on to work on high-capacity computer memory devices, and was granted a British patent in 1967 titled "Magnetic Films for Information Storage."

Hounsfield's work in this period included the problem of enabling computers to recognize patterns, thus allowing them to "read" letters and numbers. In 1967, during a long walk through the British countryside, Hounsfield's knowledge of computers, pattern recognition, and radar technology all came together in his mind. He envisioned a medical diagnostic system in which an X-ray machine would image thin "slices" through the patient's body and a computer would process the slices into an accurate representation which would display the tissues, organs, and other structures in much greater detail than a single X ray could produce. Computers available in 1967 were not sophisticated enough to make such a machine practical, but Hounsfield continued to refine his idea and began working on a prototype scanner. He enlisted two radiologists, James Ambrose and Louis Kreel, who assisted him with their practical knowledge of radiology and also provided tissue samples and test animals for scans. The project attracted support from the British Department of Health and Social Services, and in 1971 a test machine was installed at Atkinson Morely's Hospital in Wimbledon. It was highly successful, and the first production model followed a year later. These original scanners were designed for imaging the brain, and were hailed by neurosurgeons as a great advance. Before the CAT scanner, doctors wanting a detailed brain X ray had to help their equipment see through the skull by such dangerous techniques as pumping chemicals or air into the brain. As head of EMI's Medical Systems section, Hounsfield continued to improve the device, working to lower the radiation exposure required, sharpen the images produced, and develop larger models which could image any part of the body, not just the head. This "whole body scanner" went on the market in 1975.

CAT scanners generated some resistance because of their expense: even the earliest models cost over $300, 000, and improved versions several times as much. Despite this, the machines were so useful they quickly became standard equipment at larger hospitals around the world. Hounsfield argued that, properly used, the scanners actually reduced medical costs by eliminating exploratory surgery and other invasive diagnostic procedures. The scanner won Hounsfield and his company more than thirty awards, including the MacRobert Award, Britain's highest honor for engineering. In 1979, Hounsfield's collection of scientific tributes was topped off with the Nobel Prize. That year's Nobel was shared with Allan M. Cormack, an American nuclear physicist who had separately developed the equations involved in reconstructing an image via computer. A surprising feature of the selection was that neither man had a degree in medicine or biology, or a doctorate in any field. Asked what he would do with the large monetary award which came with the Nobel selection, Hounsfield replied he wanted to build a laboratory in his home. In an interview with Robert Walgate of the British journal Nature after the Nobel announcement, Hounsfield commented, "I've always searched for original ideas; I am absolutely opposed to doing something someone else has done."

Hounsfield moved on to positions as chief staff scientist and then senior staff scientist for Thorn EMI. He continued to improve the CAT scanner, working to develop a version which could take an accurate "snapshot" of the heart between beats. He has also contributed to the next step in diagnostic technology, nuclear magnetic resonance imaging. In 1986, he became a consultant to Thorn EMI's Central Research Laboratories in Middlesex, near his longtime home in Twickenham.

Further Reading on Godfrey Hounsfield

Engineers and Inventors, Harper, 1986, pp. 85-86.

Di Chiro, Giovanni, with Rodney A. Brooks, "The 1979 Nobel Prize in Physiology or Medicine, " in Science, November 30, 1979, pp. 1060-1062.

"Nobel Prizes, " in Physics Today, December, 1979, pp. 17-20.

"Nobel Prizes: Emphasis on Applications, " in Science News, October 20, 1979, p. 261.

"Scanning for a Nobel Prize, " in New Scientist, October 18, 1979, pp. 64-165.

Seligmann, Jean, "The Year of the CAT, " in Newsweek, October 22, 1979, pp. 75-76.

"Triumph of the Odd Couple, " in Time, October 22, 1979, p. 80.

Walgate, Robert, "35th Prize for Inventor of EMI X-ray Scanner, " in Nature, October 18, 1979, pp. 512-513.

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