We believe the future application of MRDTI will be enormously valuable in the early diagnosis and monitoring of DVT

Professor Alan Moody, University of Nottingham

Scientists at the University of Nottingham, who developed the method, said it could be particularly helpful for pregnant women and travellers.

Professor Alan Moody, who led the research team, said: "The great advantages that MRDTI has over other methods to detect thrombosis are that it is non-invasive, quick and reliable.

"MRDTI produces good images of the pelvis and the pregnant mother would not need X-rays for us to see the blood vessels."

The current method of detecting DVT is with venography, in which a catheter is inserted into the veins, and ultrasound.

The condition can be particularly difficult to diagnose in pregnancy if it originates in the pelvis, where it is hard to detect.

Early diagnosis

DVT has been dubbed "economy class syndrome" because it is associated with cramped conditions on aircraft, but experts say it can occur during any mode of transport after long periods of immobility.

DVT can be fatal if the blood clot, or part of it, dislodges and moves to the lungs or brain.

MRDTI is said to be very sensitive and allows radiologists to diagnose and treat the condition at a very early stage before symptoms such as leg pains develop.

A study, funded by the British Heart Foundation, and published in the medical journal the Annals of Internal Medicine, tested the method on 101 people.

The results were compared with standard tests and were found to be just as accurate.

Professor Moody said: "We believe the future application of MRDTI will be enormously valuable in the early diagnosis and monitoring of DVT."

The chances of developing DVT for most travellers are thought to be quite low. However, passengers who are overweight or obese, or those who drink heavily or smokers with existing problems, have an increased risk.

The death of a 28-year-old woman from DVT after a flight from Australia to Britain in October 2000 raised awareness of the condition.

Airlines and doctors advise travellers on long-haul flights to exercise their legs, drink plenty of water and not to drink too much alcohol.

Compression stockings help reduce the risk of DVT.