MRI may help determine time of stroke onset

November 2, 2010, Radiological Society of North America

Magnetic resonance imaging (MRI) of the brain could expand the number of stroke patients eligible for a potentially life-saving treatment, according to a new study, published online and in the December issue of the journal Radiology.

Some patients who suffer an acute ischemic stroke — in which a blood clot or other obstruction blocks blood flow in the brain -- can be treated with a drug called tissue plasminogen activator, or tPA, that dissolves the clot and restores blood flow. However, the clot-busting drug can only be administered within four and a half hours of the onset of a stroke; when given beyond that window of time, the drug can cause bleeding in the brain.

According to the American Stroke Association, stroke is the third leading cause of death in the United States behind diseases of the heart and cancer. Approximately 795,000 Americans suffer a new or recurrent stroke each year.

"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 Université Paris Descartes in France.

In the study, Dr. Oppenheim and her team of researchers reviewed data from consecutive patients with treated at Sainte-Anne Hospital in Paris between May 2006 and October 2008. The time of stroke onset was well defined in all patients and each underwent MRI within 12 hours.

The 130 patients in the study included 77 men and 53 women (mean age 64.7). Of those, 63 patients underwent MRI within three hours of stroke onset and 67 were imaged between three and 12 hours after stroke onset.

The radiologists analyzed different types of MRI data on the patients, including fluid-attenuated inversion recovery (FLAIR), diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) ratios.

Using the MRI data alone, the radiologists were able to predict with greater than 90 percent accuracy which patients had experienced stroke symptoms for longer than 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.

According to Dr. Oppenheim, 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 could be managed urgently, not just those patients with a known onset of symptoms," she said.

Dr. Oppenheim said clinical trials are the next step necessary to validate the use of MRI as a surrogate marker of duration.

Related Stories

Recommended for you

Secrets of longevity protein revealed in new study

January 17, 2018
Named after the Greek goddess who spun the thread of life, Klotho proteins play an important role in the regulation of longevity and metabolism. In a recent Yale-led study, researchers revealed the three-dimensional structure ...

Weight flux alters molecular profile, study finds

January 17, 2018
The human body undergoes dramatic changes during even short periods of weight gain and loss, according to a study led by researchers at the Stanford University School of Medicine.

The HLF gene protects blood stem cells by maintaining them in a resting state

January 17, 2018
The HLF gene is necessary for maintaining blood stem cells in a resting state, which is crucial for ensuring normal blood production. This has been shown by a new research study from Lund University in Sweden published in ...

Magnetically applied MicroRNAs could one day help relieve constipation

January 17, 2018
Constipation is an underestimated and debilitating medical issue related to the opioid epidemic. As a growing concern, researchers look to new tools to help patients with this side effect of opioid use and aging.

Researchers devise decoy molecule to block pain where it starts

January 16, 2018
For anyone who has accidentally injured themselves, Dr. Zachary Campbell not only sympathizes, he's developing new ways to blunt pain.

Scientists unleash power of genetic data to identify disease risk

January 16, 2018
Massive banks of genetic information are being harnessed to shed new light on modifiable health risks that underlie common diseases.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.