If you have kids, there’s a good chance that the very first time you laid eyes on them was via a “sonogram” image taken before they were even born. The grainy images are so common that they’ve become a rite of passage for parents all over the world. Here’s the story of how they came to be.

SHIP SHAPE

In the summer of 1955, Dr. Ian Donald, a professor of midwifery at the University of Glasgow in Scotland, was invited to take a tour of Babcock & Wilcox, a firm that manufactured steam boilers for the city’s shipbuilding industry. That’s not the kind of tour that would typically interest a physician who specializes in childbirth, but Donald wanted to see the company’s “industrial flaw detectors”—devices used to check for cracks in the welds that held the steel boilers together.

Industrial flaw detectors were a peacetime extension of sonar technology, which had been used during World War II to detect enemy submarines. Warships equipped with sonar sent bursts of sound energy in the form of “pings” through the water. If a submarine was lurking below the waves, the pings would strike the hard surface of the sub and bounce back to the warship as echoes. Analysis of the echoes would (hopefully) reveal the location of the submarine, so that it could be attacked and sunk.

The industrial flaw detectors used by B&W worked in much the same way, by bouncing ultrasound waves off the welds in steel. The resulting echoes were analyzed to see if they revealed any unseen defects in the welds.

LUMPING IT

Dr. Donald wondered if the technology could also be used to see things hidden inside the human body. The demonstration on the tour showed promise, so Donald wangled a second invitation to the boilermaker. This time he brought a selection of cysts, tumors, and other medical samples to analyze; B&W gave him a piece of steak that he could use as a control sample of healthy tissue that contained no tumors or cysts. The results were “beyond my wildest expectations,” Donald remembered 20 years later. “I could see boundless possibilities in the years ahead.”

MAD MAN

Donald could see the possibilities, but his colleagues could not. They’d long ago given him the nickname “Mad Donald” for his fascination with gadgets and his attempts to incorporate them into medicine. Though he’d had some successes, including a device that assisted struggling newborns in taking their first breath, the idea of taking tumors and cysts to a shipyard boilermaker, of all places, did not help his professional reputation one bit.

Donald wasn’t the only person interested in ultrasound: Researchers in Europe, Japan, and the United States were also experimenting with it, and their research was starting to appear in medical journals. But if Donald’s colleagues knew this, it made no difference. When he borrowed an old flaw detector from a London neurologist who’d tried (and failed) to scan human brains from outside the skull, all it did was give the other doctors a chance to drop by his office and laugh at his experiments in person.

To be fair, those experiments were quite a sight in those early days. The only way he could get his flaw detector to work was to smear the bottom of a plastic bucket with petroleum jelly and balance it precariously on a patient’s abdomen, then fill the bucket with water and immerse the ultrasound probe in the bucket. As often as not, the only result was water spilled all over the patient, the doctor, and the floor, forcing Donald to start all over again—assuming the patient was willing to risk a second drenching.

HELPING HAND

Those early results were so disappointing that Donald might have ended his research right then and there if some electricians with Kelvin & Hughes, the company that made the flaw detectors, hadn’t happened to be installing lights in a nearby operating room. When the electricians saw him bucket-scanning patients with the antiquated detector, they passed word of the ridiculous sight to Tom Brown, a brilliant 23-year-old Kelvin & Hughes engineer assigned to the flaw detector department. Intrigued, Brown looked up Mad Donald in the phone book, gave him a call, and asked if he could drop by his office for a look. The doctor agreed, and Brown soon observed that not only was Donald’s flaw detector old and obsolete, it had been modified in a way that made it all but useless. He made a few calls to his bosses at Kelvin & Hughes, and a brand-new, state-of-the-art flaw detector was soon on its way to Donald’s office.

PRESSING THE FLESH

With the new machine, balancing buckets of water on the bellies of patients was no longer required: All Donald had to do was smear the patient’s abdomen with olive oil and run the ultrasound probe over the area. Sound waves penetrated the body, and the echoes that resulted appeared as electrical impulses on the screen of a device called an oscilloscope.
Donald had long suspected that cysts, which were filled with fluid, would have a different ultrasound “signature” than tumors, which were dense masses of tissue. His earliest experiments at the boilermaker had suggested as much, and now the new equipment confirmed it. Once again, however, his colleagues dismissed his findings. Then a professor of surgery asked him to examine one of his hopeless cases, a woman dying from inoperable stomach cancer.

Donald smeared the woman’s severely distended abdomen with olive oil and ran his probe over the area. A couple of swipes was all it took: Instead of getting a reading consistent with a cancerous tumor, the industrial flaw detector revealed a pocket of fluid with clearly defined edges to it, characteristic of a cyst. The “dying” woman wasn’t dying at all. She didn’t have cancer, either, and after Donald operated and removed what he correctly diagnosed as a benign ovarian cyst, she made a full recovery.

SOUND’S GOOD

Mad Donald suddenly didn’t seem so mad after all. His strange shipyard contraption was no longer an embarrassment to be kept hidden, either. Soon every doctor had a tricky patient they wanted scanned. “As soon as we got rid of the back-room attitude and brought our apparatus fully into the Department with an inexhaustible supply of living patients with fascinating clinical problems, we were able to get ahead really fast,” Donald recounted years later. “From this point, there could be no turning back.”

COMING INTO FOCUS

As much as the new machine was an improvement over the one it replaced, it still left a lot to be desired. When Donald scanned patients, all he saw on the oscilloscope was squiggly lines. Telling one type of squiggly line from another was how he distinguished tumors from cysts, and that was good enough for him. But Tom Brown, the young engineer from Kelvin & Hughes, thought he could build something better. By late 1957, he had finished work on an improved machine that kept track of where the probe was on the patient’s body and plotted the echoes on the screen of the oscilloscope accordingly. In the process, he invented the first ultrasound scanner able to produce images—sonograms, as they came to be known—instead of squiggly lines. (Money was so tight that he actually built the machine using a borrowed hospital bed table and parts scrounged from an Erector set.)

PRE-VIEW

By the summer of 1958, Donald, Brown, and a third researcher named John MacVicar had scanned more than 100 human subjects. They published their findings in the British medical journal The Lancet, along with images of what sonograms would become best known for—human fetuses in the womb. Believe it or not, the researchers discovered ultrasound’s ability to produce these images by accident, while scanning a woman thought to be suffering from a tumor in her uterus, a condition that can cause distension of the abdomen. It wasn’t until a baby’s head appeared on the screen that they realized the distension was caused by a much more common condition: pregnancy.

But was it safe to bombard a fetus with ultrasound waves? Donald, Brown, and MacVicar didn’t see why not, but they needed to be sure, so they cranked up the machine to more than 30 times the amount of energy needed to produce images and bombarded four anesthetized kittens for an hour. When the kittens survived unharmed, the relieved researchers concluded that it was safe to use ultrasound on pregnant mothers. In the process, an entire new field of prenatal medical imaging was born—one that, unlike X-rays, produced images of soft tissue, not just bones, and posed no risk to mother and child.

HARD TO SEE

If you’ve ever struggled to pick out a fetus from the grainy, grayscale chaos of a modern sonogram, you can imagine how difficult it must have been to spot them in images produced by those first, primitive machines. Even more difficult, it turns out, was the task of convincing obstetricians, gynecologists, and other specialists that such images were useful. These professionals had always gotten by on observation, touch, and no small amount of guesswork when practicing their profession. They’d never needed ultrasound images in the past—so why did they need them now? It also took time for hospitals that had never purchased ultrasound equipment before to understand its importance, and even longer to find the money in their budgets. Thanks to this professional and bureaucratic inertia, nearly a decade passed before ultrasound imaging began to take off.

BLIND

By then Kelvin & Hughes had already exited the business. Thanks to the genius of one 23-year-old employee, the industrial flaw-detector company had a billion-dollar industry land in their lap but early sales had been too slow to convince the company’s managers that the business would ever turn a profit. So in 1967 they closed the factory in Glasgow and sold their medical imaging business to another firm.

What happened to Tom Brown, the brilliant young man who started it all? He bounced between jobs in academia and medical imaging for more than 20 years. In 1973 he signed on with another medical-imaging company and led the team that invented the world’s first ultrasound scanner capable of producing 3-D images, but again sales were slow to materialize and the company went under, taking Brown’s career with it. “I had to take the professional consequences of being associated with failure,” he told an interviewer in 1995. “No one wanted to employ me after the collapse of the 3-D project. I was unemployed and unemployable.” He spent the rest of his career in the oil industry, operating a crane. He retired in 2002 and today ekes by on a modest pension.

Decades passed before Tom Brown, Ian Donald, or John MacVicar received any recognition for their contributions to medicine. In spite of their pioneering efforts, the United Kingdom never did become a leader in the ultrasound medical imaging field. Instead, the technology passed to Japan, Germany, the United States, and other countries, where long-sighted companies were willing to invest millions on research and development and wait years for it to pay off. Today you can still have an ultrasound done in Glasgow, the city where it all began, but if you do, it will be done using a machine imported from someplace else.

SIGHT FOR SORE EYES

Tom Brown never made any money off the invention of medical ultrasound scanners: Though he’s named as the inventor on the original patent, the commercial rights were assigned to his employer, Kelvin & Hughes. (They never made any money from it, either.) Today he gets more credit for his contribution to medicine than he used to, but his greatest personal satisfaction came in 2007 when his pregnant daughter, Rhona, received a sonogram and was diagnosed with vasa praevia, a condition in which the blood vessels can rupture during natural childbirth. If they do, there’s a very high risk of the baby bleeding to death during delivery.

Before the invention of ultrasound imaging, the condition was very difficult to detect; the first sign of it often came only when the baby died as it was being born. But now it can be detected on an ultrasound scan, and because of it, Rhona had a Caesarean section and her son, named Tom in honor of his grandfather, is alive and well today. “The baby was safely delivered and is now an extremely bright, lovely little boy who wouldn’t be here but for his grandpa’s work in the past,” Brown told the BBC in 2013.