`I don't believe it,' says Nobel winner.

Byline: By Lyndsay Moss And David Stringer

A british professor honoured with a Nobel Prize for medicine yesterday for his pioneering work in the development of MRI technology said he had believed he would never receive the accolade.

Professor Sir Peter Mansfield, of the University of Nottingham, was awarded the prize jointly with American Paul C Lauterbur, who also worked in the field of magnetic resonance imaging.

MRI scans allow doctors to see detailed images of the internal organs without the use of X-rays and more than 60 million investigations using the technique take place each year.

Sir Peter said he had dismissed the idea that he would be honoured by The Nobel Assembly years ago and had struggled to believe the news he had received the prize, which includes a cheque for pounds 800,000.

"The reaction was one of shock, the time I heard was in a phone call at home and at first of all I didn't believe it," he said.

"This is a great honour for me, a great honour for British science in general and especially for the people who are continuing to work in this area at the University of Nottingham."

Sir Peter, 69, had worked in the Department of Physics at Nottingham since 1979, but has now retired and has the university's Magnetic Resonance Centre named in his honour.

"This gives a great deal of credit to the university, to Nottingham, to Britain and to the financial agencies that have offered support to us," he said. "There have been occasions in the past when we believed that we had carried out work worthy of receiving a Nobel prize, but one can't be sure.

"It is, I suppose, every scientist's hope that one day they may be singled out for such an honour, but I must say that in my case I did think about it a few years ago, but then dismissed it. What you have to do in science is to do one's best and try to survive."

The Nobel Assembly at the Karolinska Institutet in Sweden said the two joint winners had made "seminal discoveries" in the use of magnetic resonance to visualise different structures. "These discoveries have led to the development of modern magnetic resonance imaging, MRI, which represents a breakthrough in medical diagnostics and research," the assembly said.

Sir Peter, a married father of two, who was born in London, was knighted in 1993.

The technique works by turning hydrogen atoms in the tissues into radio transmitters.