Today In Science History – August 28 – Godfrey Hounsfield and the CT Scanner 1

Godfrey Hounsfield
Godfrey Hounsfield (1919 – 2004) Inventor of the CAT scan.

August 28 is Godfrey Hounsfield’s birthday. Hounsfield was the English electrical engineer who built the first x-ray computer tomography scanner or CT scanner.

Hounsfield studied radio repair in vocational school and basic electronics and radar with the Royal Air Force during World War II. After the war, he attended Faraday House Electrical Engineering College in London. He then obtained a position at Electrical and Musical Industries (EMI) where he would spend his entire career.

He had the idea of determining the contents of a box by scanning the box with x-rays from all angles, collecting all the scans and produce a 3-dimensional representation of the box’s contents. He obtained a grant from the British Health and Social Services and began to research how to build his idea. It took several years, but he managed to construct a prototype that would X-ray an object from several angles, send the x-rays to a computer so software could compile image ‘slices’ of the object. The software would then stack these slices to build a 3-dimensional image.

The first object he imaged was a preserved human brain. Following that success, he tried a fresh cow brain from a local butcher shop. When he saw his device did not damage either brain, he decided to image his own brain. Hounsfield had created the CAT scanner or CT scanner. The device would soon be installed at Atkinson Morley’s Hospital in London where in 1971, it was used to detect a cyst in a patient’s brain. CAT scanners are now common equipment and found in hospitals around the world.

Hounsfield went on to design and build the first full-body CAT scanner just four years later. He was awarded half the 1979 Nobel Prize in Medicine for this invention. He is one of the few people who has won a Nobel Prize with no formal University training.

Notable Science Events for August 28

2006 – Melvin Schwartz died.

Schwartz was an American physicist who shared the 1988 Nobel Prize in Physics with Leon Lederman and Jack Steinberger for the development of the neutrino beam method and recognition of the doublet structure of leptons with the discovery of the muon neutrino. The neutrino beam method is an experimental technique of producing high energy neutrinos to study the weak nuclear force and was important to the discovery of the quark.

1919 – Godfrey Newbold Hounsfield was born.

1878 – George Hoyt Whipple was born.

George Whipple (1878 - 1976)
George Whipple (1878 – 1976)
Nobel Foundation

Whipple was an American physician who shares the 1934 Noble Prize in Medicine with George Minot and William Murphy for their work on the treatment of anemia. Whipple showed that anemic dogs who were fed liver improved their condition, actually reversing the condition.

This discovery would lead to the successful treatment of pernicious anemia by Minot and Murphy.

1863 – André-Eugène Blondel was born.

Andre Blondel (1863 - 1938)
Andre Blondel (1863 – 1938) in his student days.

Blondel was a French physicist who made contributions to the study of photometry. He proposed the Violle candle unit as a measure of light intensity. The Violle was equal to the light intensity of 1 cm2 of platinum at 1042 K. This unit was later deprecated to the current unit of a candela (cd). He also introduced the unit of lumen for luminous flux which is still used.

In the course of his research, he invented a device called an oscillograph that was the precursor to the oscilloscope to measure the intensity of alternating currents and voltages.

1863 – Eilhardt Mitscherlich died.

Eilhard Mitscherlich (1794 - 1863)
Eilhard Mitscherlich (1794 – 1863)

Mitscherlich was a German chemist who proposed the theory of isomorphism. This theory states that chemical compounds that crystallize together have similar structure and composition. He discovered selenic acid and the mono-clinic crystal form of sulfur. He also named benzene and was the first to synthesize nitrobenzene. He was one of the first chemists to identify catalytic action and its effects on the rates of reactions.