Professor Paul Lauterbur

Engineer and Professor of Bioengineering, University of Illinois

Winner of the Nobel Prize in Medicine 2003

STOCKHOLM, Sweden (AP) - American Paul C. Lauterbur and Briton Sir Peter Mansfield won the 2003 Nobel Prize for medicine Monday for discoveries leading to a technique that reveals images of the body's inner organs.
Magnetic resonance imaging, or MRI, has become a routine method for medical diagnosis and treatment. It is used to examine almost all organs without need for surgery, but is especially valuable for detailed examination of the brain and spinal cord.

Lauterbur, 74, discovered the possibility of creating a two-dimensional picture by producing variations in a magnetic field. Lauterbur is at the Biomedical Magnetic Resonance Laboratory at the University of Illinois in Urbana.

Mansfield, 70, showed how the signals the body emits in response to the magnetic field could be mathematically analyzed, which made it possible to develop a useful imaging technique. Mansfield also showed how extremely fast imaging could be achievable. This became technically possible within medicine a decade later.

Mansfield is at the University of Nottingham in Britain.

MRI images "have an enormous impact on health care in the developed part of the world today," said Dr. Hans Ringertz, a Swedish specialist in diagnostic radiology.

Worldwide, more than 60 million investigations with MRI are performed each year, the Nobel Assembly said.

MRI represents "a breakthrough in medical diagnostics and research," the Assembly said.

Essentially, MRI turns hydrogen atoms in the body's tissues into tiny radio transmitters. Hydrogen atoms are plentiful because they're found in water molecules, which are very widespread in the body.

By tracking where those atoms are, an MRI machine can build up a picture of internal organs. It's a little like flying over a city at night, and discerning its outlines by noticing where the lights are.

The prize includes a check for 10 million kronor, or $1.3 million, and bestows a deeper sense of academic and medical integrity upon the winners.

There are no set guidelines for deciding who wins. Alfred Nobel, who endowed the awards that bear his name, simply said the winner "shall have made the most important discovery within the domain of physiology or medicine."

The assembly, which selects the medicine prize winner, invites nominations from previous recipients, professors of medicine and other professionals worldwide before whittling down its choices in the fall.

Last year's winners were Britons Sydney Brenner and John E. Sulston, and American H. Robert Horvitz for their discoveries about how genes regulate organ growth and a process of programmed cell suicide. Their findings shed light on the development of many illnesses, including AIDS and strokes. The award for medicine opens a week of Nobel Prizes that culminates Friday with the prestigious peace prize, the only one revealed in Oslo, Norway.

The physics award will be announced Tuesday and the chemistry and economics awards Wednesday in the Swedish capital.

South African writer J.M. Coetzee was awarded the Nobel Prize for literature on Thursday.

The award committees make their decisions in deep secrecy and candidates are not publicly revealed for 50 years.

Nobel, the Swedish industrialist and inventor of dynamite, left only vague guidelines in his will establishing the prizes, first awarded in 1901.

The only public hints are for the peace prize.

The five-member awards committee never reveals the candidates, but sometimes those making the nominations announce their choices.

Nobel watchers say there is no clear favorite for this year's Peace Prize, but some names bandied about include Pope John Paul II, Brazilian President Luiz Inacio Lula da Silva and Afghan President Hamid Karzai.

A record 165 nominations were received by the Feb. 1 deadline. Even though the committee keeps the names secret, those nominating a candidate often announce their preference.

Other known or likely nominees include Karzai; Cuban human rights activist Oswaldo Paya Sardinas; Chinese dissident Wei Jingsheng; former Illinois Gov. George Ryan for emptying his state's death row of 167 inmates; former Czech President Vaclav Havel; U2 singer Bono; and Mordechai Vanunu, a nuclear scientist held captive by Israel for treason-related charges.

The awards always are presented on Dec. 10, the anniversary of Nobel's death in 1896.