In the first days of 1896, just three weeks after the announcement of the discovery of what would soon be known as X-rays, a high school headmaster and math and physics teacher in the Netherlands started his own explorations using school equipment.
Three weeks after that, the headmaster, Heinrich Joseph Hoffmans, published his results, days after snapping an image of the hand of the hospital director's 21-year-old daughter, revealing the bones inside.
More than 100 years since those pioneering experiments, researchers at Maastricht University Medical Center flipped the switch on Hoffmans' still-functional machine. They measured the radiation it emitted and took another image of a hand — this time from a cadaver.
What they found revealed just how far the technology has come.
The X-day dose the hospital director's daughter's hand received in 1896 was about 1,500 times greater than she would have if X-rayed in a modern hospital. The exposure lasted 90 minutes, compared with just over 20 milliseconds today, and the X-rays included more damaging wavelengths.
"In the old days there were some incredibly high-quality images," said radiologist Ron Eisenberg of Beth Israel Deaconess Medical Center in Boston and the author of 20 books on radiology. "The only problem is it took 45 minutes to make them, so there was a very high level of exposure.
"Clearly they had to start someplace. What they did was incredible. They had no conception of the dangers of radiation."
In the weeks and months that followed Hoffmans' 1896 experiments, researchers studied the phenomenon intensely. Doctors adopted X-rays for medical uses within weeks. But the doses were high, as the new experiments underscored, leading to hand burns, lost hair, amputations and ultimately cancer in people who worked closely with the machines.
Better X-ray equipment and protection followed fairly swiftly after the problems emerged.
"Clearly, the experiments in 1896 in Maastricht were considered pioneering work," wrote the authors, led by physicist Gerrit Kemerink, in the journal Radiology.
Indeed, machines have come a long way since this early example, with a key advance coming in 1913 when William Coolidge invented a new, more controllable tube. Better filtering of damaging X-ray wavelengths and more sensitive detectors among other improvements have allowed better images from dramatically less radiation, Kemerink said.
Traditional X-rays have led to advanced medical applications like CT scans, which create three-dimensional images and allow more refined diagnostics. Focused X-rays are used to treat cancer. And X-rays are used in physics to study everything from astronomy to the material properties.
Coincidentally, researchers in Kemerink's department recently conducted an experiment measuring the radiation exposure of the X-ray technicians in the hospital, Kemerink said. The team determined that thanks to the modern protective measures the workers received less radiation exposure at work than they did in their homes, which typically have some radon and which shield less cosmic radiation than the concrete hospital.
"From something that was life-threatening, we have come to a situation where it is no longer so," he added.
"I thought this was just a wonderfully interesting paper and points out to us how much progress we've made in the last 115 years," said Donald Frey of the Medical University of South Carolina. "It makes you wonder what in 100 years people will think about 100-year-old X-ray equipment, if there's any that's still working."
The research also offered Kemerink's team a glimpse of what it might have been like for Hoffmans and other x-ray pioneers who first viewed the bones inside our bodies with the eerie apparatus.
Kemerink's team wrote: "Our experience with this machine, which had a buzzing interruptor, crackling lightning within a spark gap, and a greenish light flashing in a tube; which spread the smell of ozone; and which revealed internal structures in the human body was, even today, little less than magical."