Sir Godfrey Hounsfield, Who Helped Develop the CAT Scanner, Dies at 84

August 20, 2004


Sir Godfrey Hounsfield, a British electrical engineer whose work in creating the computerized axial tomography scanner, the CAT scan, a diagnostic tool used in hospitals worldwide, won him a Nobel Prize, died Aug. 12 at New Victoria Hospital in Kingston upon Thames, England. He was 84.

The cause of death was not reported, said Dr. Ken Gray, a friend and former colleague.

In work that began in the 1960's, Sir Godfrey built a machine that used X-rays to make three-dimensional images of the body's interior, allowing doctors a new and cross-sectional view of organs, bones and other tissues. In the 1970's, CAT-scan technology spread rapidly to hospitals.

"The breakthrough was the realization that by scanning objects at many angles, it was possible to extract 100 percent of information" from X-rays, he said in 1973, in an interview with The New York Times.

Sir Godfrey was recognized with the Nobel Prize in Physiology or Medicine in 1979. He shared the award with Allan M. Cormack, a South African scientist who worked independently on the concept. Dr. Cormack died in 1998.

"The CAT scanner revolutionized medical care in the United States and throughout the world," said Dr. James A. Brink, interim chairman of diagnostic radiology at the Yale University School of Medicine.

"That's not to say it can do everything, but it is a tool with profound benefits, a great tool," said Dr. Brink, adding that about 7,000 CAT scanners were in use nationwide by 2000.

Without a university degree, Sir Godfrey began his research career at Electrical and Musical Instrument Ltd. in 1951.

After early work on radar and guided weapons systems, he became interested in computers and led a team that built the first all-transistor computer in Britain. In the 1960's, Sir Godfrey applied that knowledge in the development of the scanner, which relied on powerful computers to assemble its images.

The prototype CAT scanner was designed only to examine the head. Today's machines can scan the entire body while a patient lies on a moving table, with an X-ray tube and multiple detectors spiraling around the body. The Nobel Committee's presentation speech said that before the CAT scanner, "ordinary X-ray examinations of the head had shown the skull bones, but the brain had remained a gray, undifferentiated fog."

"Now, suddenly, the fog had cleared."

Godfrey Newbold

Hounsfield was born on Aug. 28, 1919, in Newark, England. The youngest child of a farmer, he recalled, in an autobiographical sketch he wrote for the Nobel committee, that a rural and solitary youth "gave me the advantage of not being expected to join in, so I could go off and follow my own inclinations."

After serving as a radar mechanic instructor in the Royal Air Force, he received a diploma from the Faraday House Electrical Engineering College in London.

At Electrical and Musical Instrument, he became head of the medical systems section for the company's Central Research Laboratories, from 1972 to 1976. He was ultimately made a senior staff scientist and retired in 1986. He never married.

Sir Godfrey was elected a fellow of the Royal Society in 1975, and was knighted in 1981. His name is used to describe the brightness of images that appear on the CAT scanner. The images are measured in Hounsfield units.