Wednesday, October 1, 2014

Happy October 1, the Day of the CT Scan

This is the anniversary of the CT or CAT scan.


The first Computed Tomography scan was performed on a patient on October 1, 1971. It's also known as a CT scan or sometimes a CAT scan, for Computed Axial Tomography. A CT scan produces images of cross sections or "slices" of the human body. It makes it possible for doctors to examine the soft tissues of the body, which are difficult to see with traditional X-rays. In 1971, the scanner took about five minutes to capture a single slice, and it took a couple of hours to produce a single image from the raw data. Today's scanners can capture multiple slices and return images, all in under a second.
The first diagnostic scan was performed at Atkinson Morley's Hospital in London, and the first patient was a woman who was suspected of having a tumor in her frontal lobe. The scan — quite blurry by today's standards — revealed what appeared to be a mass. When surgeons opened up the woman's skull, one of them remarked that it looked exactly like the picture. The CT scan had proved its usefulness.
Partial credit for the development of the CT scanner is due the Beatles, according to British radiologist Ben Timmis. That's because the band's recording label, EMI, heavily funded the research of the CT's inventor, Sir Godfrey Hounsfield. Because the Beatles sold so many records and made so much money for EMI, Hounsfield was able to devote four years of full-time work to the development of a commercial CT machine, which was called the EMI-Scanner.
There were five separate researchers working on tomography in the 1960s. Godfrey Hounsfield was the dark horse. He wasn't an academic and didn't publish papers. He didn't apply for any patents until very late in the process, and he was funded internally by his employer, so he never needed to apply for any grants. He had no medical background, and he completed most of his work in secret. The major drawback to his method was that, when the time came to approach practicing neurologists with his invention, he had no track record and was viewed as a crackpot. He finally found an ally in Jamie Ambrose, a consultant radiologist at London's second-best neurological hospital. They began working together in 1967 — again, under strictest secrecy.
Hounsfield tested his scanner first on a preserved human brain, then on a fresh cow brain. Before he tried it on a real patient, he tested it on himself. He performed his first clinical scan for the purpose of diagnosing an actual patient on this date in 1971. He used a prototype scanner installed at Atkinson Morley's Hospital, an old Victorian building up on a hill in Wimbledon. The first patient was a woman whose doctors suspected she had a brain lesion. The scan was pretty blurry by today's standards, but it revealed what appeared to be a dark, circular cyst. When surgeons eventually opened up the woman's skull, one of them remarked that the tumor looked exactly like the picture. The CT scan had proved its usefulness — especially in the area of brain imaging, where accuracy is of vital importance. The CT was about a hundred times more detailed than a regular X-ray. After the successful trial, doctors at Atkinson Morley's Hospital grew fond of saying, "One CT scan is worth a room full of neurologists."

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