Two scientists who played a key role in the development of modern hospital scanners won the 2003 Nobel prize for medicine today.
American Mr Paul Lauterbur and Britain's Mr Peter Mansfield were recognised for their discoveries on magnetic resonance imaging (MRI), a painless diagnostic method used by doctors to look inside the bodies of millions of patients every year.
"They have made seminal discoveries concerning the use of magnetic resonance... which represents a breakthrough in medical diagnostics and research," the Nobel Assembly of Sweden's Karolinska Institutet university hospital said in its citation for the prize - worth $1.3 million.
The scientists' work led to the development of modern MRI, which yields three-dimensional images of organs inside the body.
The now-routine technique lets doctors see the extent of a tumour, localise an inflammation in the nervous system, or even see a beating heart.
MRI has helped replace invasive examinations and reduced the risk and discomfort of medical tests ahead of surgery. It is valuable in imaging the brain and spinal cord, and has played an important role in the improved treatment of multiple sclerosis, cancer and Parkinson's disease.