Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Carotid Artery MRI helps predict likelihood of strokes and heart attacks

04.03.2014

Noninvasive imaging of carotid artery plaque with MRI can accurately predict future cardiovascular events like strokes and heart attacks in people without a history of cardiovascular disease, according to a new study published online in the journal Radiology.

Researchers have long known that some arterial plaque is more dangerous because of its vulnerability to rupture. MRI can discern features of vulnerable plaque, such as a lipid core with a thin fibrous cap. This ability makes MRI a potentially valuable tool for identifying patients at risk for subsequent cardiovascular events.

Transverse Gadolinium-enhanced T1-weighted MR

This shows transverse gadolinium-enhanced T1-weighted MR images obtained superior to the carotid artery bifurcation in a 72-year-old man. L = ICA lumen. (a) Low-signal-intensity calcium (arrow) and lipid core (arrowheads) can be seen. (b) Note contouring of the ICA. The outer adventitial wall (red), lipid core (blue), calcification (green), and vessel lumen (purple) are visible.

Credit: Radiological Society of North America

To study the predictive value of MRI plaque imaging, researchers performed carotid artery ultrasound and MRI on 946 asymptomatic patients from the Multi-Ethnic Study of Atherosclerosis (MESA). The carotid arteries are the large vessels located on each side of the neck that carry oxygenated blood to the front part of the brain. They are highly accessible for imaging, and their condition tends to mirror that of the coronary arteries that supply the heart with oxygenated blood.

The researchers used ultrasound to assess carotid wall thickness and MRI to define carotid plaque composition and the remodeling index, a measure of changes in vessel size. Imaging results were compared with cardiovascular events, including heart attacks, stroke and death, for an average of 5.5 years after examination.

"We studied asymptomatic individuals with a low risk of cardiovascular events at baseline and used noninvasive imaging to predict the risk of an event downstream," said David A. Bluemke, M.D, Ph.D., from the National Institutes of Health Clinical Center in Bethesda, Md. "This is the first population-based prospective study to determine if vulnerable plaque features by MRI add to the risk of a cardiovascular event beyond the traditional risk factors."

Cardiovascular events occurred in 59 of the patients. Abnormal thickening of the carotid artery wall and the presence of a lipid core and calcium in the internal carotid artery on MRI were significant predictors of subsequent events. A lipid core was present in almost half of the patients who had an event, compared with only 17.8 percent of those who did not have an event.

"The primary factors that predicted future risk were measures of vessel wall thickness in combination with the presence or absence of a lipid core," Dr. Bluemke said. "The presence of a lipid core was 50 percent more common in people who had subsequent events."

Use of MRI improved the reclassification of baseline cardiovascular risk in the study group. When both the carotid remodeling index and lipid core were used for risk stratification, approximately 16 percent more patients with events and 7 percent without events were correctly reclassified compared with the use of traditional risk factors.

"The results bolster the use of MRI as a surrogate marker of efficacy in therapeutic studies and point to a role in determining which patients might need more aggressive treatments," Dr. Bluemke said. "As risk factor prediction gets better, we'll be able to screen more intelligently and use more intensive treatments in those individuals who face a higher risk of cardiovascular events."

Dr. Bluemke noted that sequences for plaque composition could be readily added to existing carotid MRI angiography protocols for clinical purposes.

"Carotid MRI has significant advantages," he said. "The results are more reproducible than those of ultrasound."

Availability and cost effectiveness could limit the use of MRI, Dr. Bluemke cautioned. However, ultrasound and computed tomography (CT) are viable alternatives for screening, he said, especially with improvements in CT dose reduction.

###

"Carotid Artery Plaque Morphology and Composition in Relation to Incident Cardiovascular Events: The Multi-Ethnic Study of Atherosclerosis (MESA)." Collaborating with Dr. Bluemke were Anna E. H. Zavodni, M.D., Bruce A. Wasserman, M.D., Robyn L. McClelland, Ph.D., Antoinette S. Gomes, M.D., Aaron R. Folsom, M.D., M.P.H., Joseph F. Polak, M.D., M.P.H., and João A. C. Lima, M.D.

Radiology is edited by Herbert Y. Kressel, M.D., Harvard Medical School, Boston, Mass., and owned and published by the Radiological Society of North America, Inc.

RSNA is an association of more than 53,000 radiologists, radiation oncologists, medical physicists and related scientists promoting excellence in patient care and health care delivery through education, research and technologic innovation. The Society is based in Oak Brook, Ill.

For patient-friendly information on MRI, visit RadiologyInfo.org.

Linda Brooks | EurekAlert!

Further reports about: MRI atherosclerosis coronary arteries heart attacks

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Viaducts with wind turbines, the new renewable energy source

Wind turbines could be installed under some of the biggest bridges on the road network to produce electricity. So it is confirmed by calculations carried out by a European researchers team, that have taken a viaduct in the Canary Islands as a reference. This concept could be applied in heavily built-up territories or natural areas with new constructions limitations.

The Juncal Viaduct, in Gran Canaria, has served as a reference for Spanish and British researchers to verify that the wind blowing between the pillars on this...

Im Focus: X-rays and electrons join forces to map catalytic reactions in real-time

New technique combines electron microscopy and synchrotron X-rays to track chemical reactions under real operating conditions

A new technique pioneered at the U.S. Department of Energy's Brookhaven National Laboratory reveals atomic-scale changes during catalytic reactions in real...

Im Focus: Iron: A biological element?

Think of an object made of iron: An I-beam, a car frame, a nail. Now imagine that half of the iron in that object owes its existence to bacteria living two and a half billion years ago.

Think of an object made of iron: An I-beam, a car frame, a nail. Now imagine that half of the iron in that object owes its existence to bacteria living two and...

Im Focus: Thousands of Droplets for Diagnostics

Researchers develop new method enabling DNA molecules to be counted in just 30 minutes

A team of scientists including PhD student Friedrich Schuler from the Laboratory of MEMS Applications at the Department of Microsystems Engineering (IMTEK) of...

Im Focus: Bionic eye clinical trial results show long-term safety, efficacy vision-restoring implant

Patients using Argus II experienced significant improvement in visual function and quality of life

The three-year clinical trial results of the retinal implant popularly known as the "bionic eye," have proven the long-term efficacy, safety and reliability of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

World Conference on Regenerative Medicine in Leipzig: Last chance to submit abstracts until 2 July

25.06.2015 | Event News

World Conference on Regenerative Medicine: Abstract Submission has been extended to 24 June

16.06.2015 | Event News

MUSE hosting Europe’s largest science communication conference

11.06.2015 | Event News

 
Latest News

Siemens receives order for offshore wind power plant in Great Britain

03.07.2015 | Press release

'Déjà vu all over again:' Research shows 'mulch fungus' causes turfgrass disease

03.07.2015 | Agricultural and Forestry Science

Discovery points to a new path toward a universal flu vaccine

03.07.2015 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>