CT scan

The CT scanner emerged from one of the strangest funding stories in medical history: Beatles record sales financing a diagnostic revolution. Godfrey Hounsfield, an electrical engineer at EMI in Hayes, England, had spent sixteen years working on radar, guided weapons, and Britain's first all-transistor computer. By 1967, EMI—enriched considerably by their recording artists' success—gave Hounsfield funding to pursue an eccentric idea: using computers to reconstruct three-dimensional images from X-rays taken at multiple angles.

The adjacent possible required three convergent technologies. X-ray tubes had existed since 1895 but produced only flat shadow images. Computers had become powerful enough to perform the complex mathematical reconstructions Hounsfield envisioned. And critically, the theoretical mathematics had already been solved—though Hounsfield didn't know it. Johann Radon had published the relevant equations in 1917, and South African physicist Allan Cormack had independently developed the mathematical solutions in the 1960s while working on radiation therapy planning. Neither man knew of the other's work; neither knew of Hounsfield.

Hounsfield's prototype took nine days to scan an object and two and a half hours to process the image on a mainframe computer. He began with preserved human brains, then pig heads from a butcher shop. The results were astonishing: cross-sectional images that revealed internal structures X-rays had never shown.

The first clinical CT scanner was installed at Atkinson Morley Hospital in London. On October 1, 1971, doctors scanned their first patient: a middle-aged woman showing signs of a brain tumor. The five-minute scan took two 13-millimeter-thick slices, revealing a cystic mass the size of a plum on her left frontal lobe. For the first time, doctors could see inside a living brain without surgery.

Convergent evolution had occurred independently. Cormack, working in Cape Town and later Tufts University, had developed the mathematical foundation without building a scanner. Hounsfield, working in England, had built a scanner without knowing the mathematics existed. The two men had never met and neither had expressed prior interest in medicine.

The cascade from CT scanning transformed diagnosis. Brain tumors, strokes, and head injuries could be visualized immediately. The technology rapidly expanded to whole-body scanning. By the mid-1970s, EMI dominated the market—until competitors like GE and Siemens, with deeper healthcare experience, overtook them. EMI eventually exited medical equipment entirely.

In 1979, Hounsfield and Cormack shared the Nobel Prize in Physiology or Medicine. Hounsfield was knighted in 1981. His name lives on in the Hounsfield scale, measuring radiodensity in CT images: air at -1000 HU, water at 0 HU, dense bone at +1000 HU.

The "Beatles funded the CT scanner" narrative remains debated. Some historians argue EMI's music profits directly enabled Hounsfield's research; others note the project operated on a shoestring budget regardless. What's undisputed is that a record company engineer, working on equipment usually reserved for listening to the Fab Four, changed the face of modern medicine.

By 2026, over 80 million CT scans are performed annually in the United States alone. The technology Hounsfield prototyped with pig heads has become essential infrastructure for emergency medicine, oncology, and surgical planning worldwide.