Brain scans help doctors diagnose stroke

Scientists at Cambridge University believe that their three minute scan provides the same information as one taking 20 minutes to complete.

As well as being easier for patients, the technique could mean swifter access to drugs that break up blood clots.

Doctors believe that the speed with which a patient gets these drugs may be a factor in their successful recovery.

Patients who have a stroke caused by a clot on the brain should be given thrombolytic drugs within three hours of the stroke in an attempt to minimise damage by breaking up the clots.

However, before these can be given safely, a second type of stroke, caused by a burst blood vessel within the brain, must be ruled out by a brain scan, as the drugs could make this type of stroke far worse.

Good quality

The Cambridge team have adapted an MRI scanner so that it produces the same number of images, but in a fraction of the time.

The images are of sufficient quality for doctors to spot whether a blood vessel is blocked.

It could make quite a big difference in the benefits you are likely to get from clot-busting treatment, in terms of disability and death Dr Tony Rudd, St Thomas' Hospital

Another advantage is that it is far easier for someone who has suffered a stroke to hold steady for three minutes under a scanner than 20 minutes.

Dr Jonathan Gillard, who led the study, said: "The three-minute scan is as good as the 20-minute version, and in some instances better because stroke patients may be distressed and move around.

"Despite the machine noise and possible claustrophobia, agitated patients are more likely to remain still during a quick procedure than a lengthy one."

Dr Tony Rudd, a consultant stroke physician from Guy's and St Thomas' Hospital Trust in London, told BBC News Online that even a few minutes saved could be important.

He said: "It could make quite a big difference in the benefits you are likely to get from clot-busting treatment, in terms of disability and death."

However, he said that few centres in the UK were even attempting to offer thrombolytic treatment for stroke - and that MRI scanning, despite its advantages, remained a relative rarity.

The study was presented to the Annual Meeting of Radiological Society of North America.