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X-rays beam through each ‘slice’ of brain, oriented at each degree from 1 to 180 in a semicircle.
Edmund S. Higgins,
Calculating the strength of each X-ray once it’s passed through the object, and working backward with an impressive algorithm, it is possible to construct an image.
Edmund S. Higgins,
Schematic diagram of the CT scanner included in Hounsfield’s U.S. patent.
The first clinical CT scan, with brain tumor visible as darker blob.
‘Medical Imaging Systems: An Introductory Guide,’ Maier A, Steidl S, Christlein V, et al., editors., CC BY
And there it was – in her left frontal lobe – a cystic mass about the size of a plum. With that, every other method of imaging the brain was obsolete.
Millions of CT scans every year
EMI, with no experience in the medical market, suddenly held a monopoly for a machine in high demand. It jumped into production and was initially very successful at selling the scanners. But within five years, bigger, more experienced companies with more research capacity such as GE and Siemens were producing better scanners and gobbling up sales. EMI eventually exited the medical market – and became a case study in why it can be better to partner with one of the big guys instead of trying to go it alone.
Hounsfield’s innovation transformed medicine. He shared the Nobel Prize for Physiology or Medicine in 1979 and was knighted by the Queen in 1981. He continued to putter around with inventions until his final days in 2004, when he died at 84.
In 1973, American Robert Ledley developed a whole-body scanner that could image other organs, blood vessels and, of course, bones. Modern scanners are faster, provide better resolution, and most important, do it with less radiation exposure. There are even mobile scanners.
By 2020, technicians were performing more than 80 million scans annually in the U.S.. Some physicians argue that number is excessive and maybe a third are unnecessary. While that may be true, the CT scan has benefited the health of many patients around the world, helping identify tumors and determine if surgery is needed. They’re particularly useful for a quick search for internal injuries after accidents in the ER.
And remember Hounsfield’s idea about the pyramids? In 1970 scientists placed cosmic ray detectors in the lowest chamber in the Pyramid of Khafre. They concluded that no hidden chamber was present within the pyramid. In 2017, another team placed cosmic ray detectors in the Great Pyramid of Giza and found a hidden, but inaccessible, chamber. It’s unlikely it will be explored anytime soon.
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Edmund S. Higgins, Affiliate Associate Professor of Psychiatry & Family Medicine, Medical University of South Carolina
This article is republished from The Conversation under a Creative Commons license. Read the original article.