By Jane Elliott
Health reporter, BBC News
World War II may be remembered as a time of hardship and privation.
Ian Donald, one of the early pioneers, who died in 1987
But it was also a time of incredible technological advance.
And - thanks to the dedicated efforts of a group of British researchers - it sowed the seeds for a revolution in medical care.
This week marks 50 years since a landmark paper in The Lancet medical journal introduced the world at large to the concept of medical ultrasound scans.
It is a technique which has transformed the management of pregnancy, and gynaecological conditions for millions of women worldwide.
And it has very many applications across the entire range of medicine.
The publication of The Lancet paper marked the culmination of years of hard work by the researchers, who modified sonar technology originally perfected to track wartime submarines.
They were led by Glasgow obstetrician and gynaecologist Professor Ian Donald, who had developed an interest in sonar during his service with the RAF.
Working with his colleague John MacVicar and engineer Thomas Brown, he was able to adapt the technology to analyse soft tissue and distinguish movement within the human body.
"It was rather marvellous to see inside the body," said Professor John MacVicar, who says he had no idea just what an impact their work would come to have.
"Of course there were X-rays, but to be able to tell the differences in soft tissue - that was something.
"We used echoes. It was exactly the same as radar on a submarine screen.
Ultrasound image of an ovarian cyst published in 1958 Lancet study
"We could see the baby moving, it was there and then it shifted."
Professor Donald began his work by experimenting with ultrasonic metal flaw detectors, used to detect cracks and problems with metal structures.
He was convinced that the equipment could be used to detect and identify fibroids and ovarian cysts.
He initially scanned lumps of meat and compared the results with scans of tissue removed from bodies such as cysts.
But early results were poor, as the equipment they were using only produced simple images not suitable for the complex medical diagnosis he wished to carry out.
The real breakthrough came when Mr Brown developed a new type of hand-held scanner which could be moved across the patient's abdomen.
This allowed greater control of the angle at which the ultrasound wave was introduced into the body, and produced detailed two-dimensional images which could be displayed on an oscilloscope.
Eventually the team diagnosed a huge, easily removable ovarian cyst in a woman who had wrongly been diagnosed with inoperable stomach cancer.
Her results and those of 100 patients were published in the Lancet and the world started to take notice.
Professor Donald, who died in 1987, later called the paper his most important work.
He once said: "From this point there could be no turning back.
"I think I shall always look back on that article as the most important I ever wrote and what is comforting is that all the conclusions which we reached at that time have since been vindicated by further results."
Professor MacVicar said obstetrics and gynaecology turned out to be an ideal specialty in which to pioneer medical ultrasound.
Today all pregnant women are offered scans
"We were very lucky that because we were gynaecologists that we had big lumps like ovarian cysts and fibroids to work with," he said.
However, it took time for the new technique to catch on, and initially it was not embraced by everybody in the scientific community.
"But by the time the paper was published and people digested it they began to say 'there is something in this, I think we should try it'," said Professor MacVicar.
"More and more people tried it and it went on from detecting big masses, into pregnancies.
"People suddenly thought this is something really worthwhile.
"Then they started measuring the baby's head so you began to see the growth of a baby - that was really something."
Making the technology work
Engineer Thomas Brown, who was honoured last year by the Royal College of Obstetricians and Gynaecologists for his work on ultrasound, agreed the collaboration had been remarkably fruitful.
"The problem with the human body is that there are echoes coming from all over the place that are difficult to interpret," he said.
"It seemed clear to me that there was need for some sort of device that would actually plot where the echoes were coming from."
Alan Cameron, professor of foetal medicine at the Queen Mother's Hospital, Glasgow, said ultrasound was now invaluable to clinicians like himself.
"We use ultrasound in every single clinical area where we work," he said.
"I can't imagine being without it. We just could not do anything that we do from dating pregnancies to diagnosing problems or diagnosing the early signs of ovarian cancer.
"Without doubt it is one of the greatest medical inventions in our field."