Magnetic resonance imaging of the brain increased the chances of patients affected with stroke availing lifesaving treatment. The study was published in the December issue of Journal Radiology.

A drug known as tissue plasminogen activator, or tPA, dissolves the clot and helps restore the blood flow. It can be used for patients suffering acute ischemic stroke. The drug is required to be administered within four and a half hours of the commencement of the stroke. If delayed it may lead bleeding in the brain. Around 795,000 Americans suffer a new or recurrent stroke each year, according to American Stroke Association. It is known to be the third largest cause of deaths in U.S. leaving behind cancers and heart disease.

"As many as a quarter of all stroke patients cannot be given tPA because they wake up with stroke symptoms or are unable to tell their doctor when their stroke began," said lead researcher Catherine Oppenheim, M.D., Ph.D., professor of radiology at University Paris Descartes in France.

Data was collected by Dr.Oppenheim and her team from patients with acute ischemic stroke treated at Sainte-Anne Hospital, Paris. The onset of stroke was found to be distinct in all patients. Each patient underwent an MRI within 12 hours of the stroke. The study included a total of 130 patients. Within three hours of the stroke 63 patients underwent MRI while 67 were imaged between three and 12 hours after the onset of the stroke.

The radiologists predicted with nearly 90 percent accuracy the patients who suffered from stroke for over three hours. "When the time of stroke onset is unknown, MRI could help identify patients who are highly likely to be within the three-hour time window when tPA is proven effective and approved for use," Dr. Oppenheim said. “Using MRI to determine the duration of a stroke would change the way stroke is managed in the emergency setting.

With the use of MRI, all stroke patients could be managed urgently, not just those patients with a known onset of symptoms. clinical trials are the next step essential to confirm the use of MRI as a substitute marker of stroke duration,” she added.