The Writer's Almanac with Garrison Keillor

The first diagnostic Computed Tomography scan was performed in London on this date in 1971. The technology combines X-ray imaging with the power of computers, and it's also known as a CT scan or sometimes a CAT scan. A CT scan produces images of cross-sections or "slices" of the human body, which can then be put together into a three-dimensional picture. Doctors are able to tell the difference between soft tissues, tumors, and blood clots based on CT images, and they can also determine how deep a tumor goes into the surrounding tissue, something that isn't possible with a two-dimensional X-ray. The prototype CT machine took 160 parallel scans about an inch apart, and each scan took about five minutes to complete. Doctors then had to wait more than two hours while the images were processed. Today, a scanner captures "slices" just millimeters apart and returns the images in seconds.

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."

It's the birthday of prolific novelist and short-story writer Ernest Haycox (books by this author), who was born in Portland, Oregon, in 1899 and is probably best known for the story "Stage to Lordsburg," which became John Wayne's Stagecoach, and the novel Alder Gulch, which became the Jimmy Stewart film The Far Country.

Haycox published two dozen novels and more than 300 short stories. He became a regular contributor to Collier's Weekly and The Saturday Evening Post, both of which published many of his stories and serialized a number of his novels. He wrote of stampedes, gold rushes, feuds, saloon brawls, marshals, Indians, soldiers, and solid citizens trying to eke a living out of stubborn land. Gertrude Stein and Ernest Hemingway were both fans of his work, the latter once stating that he never missed The Saturday Evening Post whenever it had a Haycox serial.

It's the birthday of novelist Tim O'Brien (books by this author), born in Austin, Minnesota (1946). He grew up in Worthington, Minnesota — the turkey capital of the world — and was drafted to fight in the Vietnam War the summer he graduated from college. He served for four years, during which time he wrote several stories and articles, and when he returned home, he got a job at The Washington Post. He published his first book in 1973; it was a memoir called If I Die in a Combat Zone, Box Me Up and Ship Me Home. After that, he began to write books that blurred the lines between fiction and memoir. His most famous book, a collection of linked short stories about the war, is The Things They Carried (1990); the stories in it feature a character named Tim O'Brien. In it, he wrote: "I want you to feel what I felt. I want you to know why story-truth is truer sometimes than happening-truth."

It's the 90th birthday of Jimmy Carter (books by this author), born in Plains, Georgia (1924). He took over the family peanut farm after his father died in 1953, and he expanded the farm into a fertilizer business, a farm supply business, and a peanut-shelling plant. He got interested in politics after he refused to join a citizens' group that opposed the integration of schools. He became the governor of Georgia and then, in 1977, the 39th president of the United States. Carter said he wanted to end what he called "the imperial presidency." He walked down Pennsylvania Avenue for his inauguration, often wore informal clothes at official appearances, and sold the presidential yacht. Jimmy Carter said: "A strong nation, like a strong person, can afford to be gentle, firm, thoughtful, and restrained. It can afford to extend a helping hand to others. It is a weak nation, like a weak person, that must behave with bluster and boasting and rashness and other signs of insecurity."