An American and a Briton won the Nobel Prize in medicine Monday for discoveries that led to MRI, the body-scanning technique that has revolutionized the detection of disease by painlessly revealing internal organs in 3-D detail.

Paul C. Lauterbur, 74, of the University of Illinois at Urbana-Champaign and Sir Peter Mansfield, 69, of the University of Nottingham in England were honored for work they did independently of each other in the 1970s.

Magnetic resonance imaging, or MRI, represents “a breakthrough in medical diagnostics and research,” with more than 60 million procedures done each year around the world, the Nobel Assembly in Stockholm, Sweden, said.

The now-routine technique became available to doctors in the 1980s. It excels at creating images of soft tissue, allowing many patients to avoid exploratory surgery. For example, doctors can see a tumor in the abdomen or get detailed images of cartilage and ligaments within the knee without operating.

MRI can also reveal whether lower back pain stems from pressure on a nerve or the spinal cord. It can show chemical changes in tissue that indicate disease. And it can lay out road maps for surgeons before they operate for diseases.

Lauterbur said he was “surprised and very gratified” by the award. “In particular, I believe, I think the work has been helpful to many people, and I’m happy that has been acknowledged by the Swedish academy,” he said.

The Nobel in medicine comes with a check equivalent to $1.3 million.

American Paul C. Lauterbur shows off his photo of the first magnetic resonance imaging. Lauterbur on Monday shared the 2003 Nobel Prize for medicine for discoveries leading to the development of MRI.