CT and Sir Godfrey Hounsfield

Sir Godfrey Newbold Hounsfield. Photograph: mc.vanderbilt.edu

Sir Godfrey Newbold Hounsfield CBE, FRS (28 August 1919 - 12 August 2004) was an English electrical engineer who shared the Nobel Prize for Physiology or Medicine with Allan McLeod Cormack, for his part in developing the diagnostic technique of X-ray computed tomography. 

The Hounsfield scale, a measure of radiodensity used in CT scan evaluations, is named after him. The scale's units is defined in Hounsfield Units.

Godfrey was born in Sutton-on-Trent, England. He had two elder brothers and two elder sisters. He was intrigued by electrical gadgets, and he tinkered with his own electronic machines, launched himself off haystacks with his own home-made glider, and almost killed himself by using water-filled tar barrels. He went to Magnus Grammar School and excelled in physics and mathematics.

Just before World War II, he joined the Royal Air Force, where he learned the basics of electronics and radar. After, he attended Faraday House Electrical Engineering School. He graduated with a Diploma of Faraday House.

In 1951, he began working at EMI Ltd, where he began researching guided weapon systems and radar. It is here he became interested in computers and helped design the first commercially available all-transistor computer: the EMIDEC 1100. 

Hounsfield came up with the idea that one could determine what was inside a box by taking X-ray readings at all angles around the object. He then constructed a computer that could take X-rays input at varying angles to create an image of the object in "slices". Applying this to the medical field led him to propose what is now known as computed tomography. At the time, Hounsfield was not aware of Cormack, who had done work on the theoretical mathematics for such a device.

Hounsfield built a prototype head scanner and first tested it on a preserved human brain, then on a fresh cow brain from a butcher shop, and later on himself. On 1 October 1971, CT scanning was introduced into medical practice with a successful scan on a cerebral cyst patient at Atkinson Morley Hospital, London. In 1975, Hounsfield built a whole-body scanner.