Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

MRI technique detects evidence of cognitive decline before symptoms appear

07.10.2014

A magnetic resonance imaging (MRI) technique can detect signs of cognitive decline in the brain even before symptoms appear, according to a new study published online in the journal Radiology. The technique has the potential to serve as a biomarker in very early diagnosis of preclinical dementia.

The World Health Organization estimates that dementia affects more than 35 million people worldwide, a number expected to more than double by 2030. Problems in the brain related to dementia, such as reduced blood flow, might be present for years but are not evident because of cognitive reserve, a phenomenon where other parts of the brain compensate for deficits in one area. Early detection of cognitive decline is critical, because treatments for Alzheimer's disease, the most common type of dementia, are most effective in this early phase.


This image shows brain perfusion. Red indicates low perfusion, yellow indicates high perfusion. Overall, the brain perfusion is similar between all three groups. The most prominent difference is present in the posterior cingulate cortex (indicated by the arrow), a region close to the midline in the superior and posterior part of the brain. Control participants who remain stable have higher perfusion as compared to deteriorating controls and MCI.

Credit: Radiological Society of North America

Researchers recently studied arterial spin labeling (ASL), a promising MRI technique that doesn't require injection of a contrast agent. ASL measures brain perfusion, or penetration of blood into the tissue.

"ASL MRI is simple to perform, doesn't require special equipment and only adds a few minutes to the exam," said study author Sven Haller, M.D., from the University of Geneva in Geneva, Switzerland.

The study group included 148 healthy elderly participants and 65 people with mild cognitive impairment (MCI). The participants underwent brain MRI and a neuropsychological assessment, a common battery of tests used to determine cognitive ability.

Of the 148 healthy individuals, 75 remained stable, while 73 deteriorated cognitively at 18 months clinical follow-up. Those who deteriorated had shown reduced perfusion at their baseline ASL MRI exams, particularly in the posterior cingulate cortex, an area in the middle of the brain that is associated with the default mode network, the neural network that is active when the brain is not concentrating on a specific task. Declines in this network are seen in MCI patients and are more pronounced in those with Alzheimer's disease.

The pattern of reduced perfusion in the brains of healthy individuals who went on to develop cognitive deficits was similar to that of patients with MCI.

"There is a known close link between neural activity and brain perfusion in the posterior cingulate cortex," Dr. Haller said. "Less perfusion indicates decreased neural activity."

The results suggest that individuals with decreased perfusion detected with ASL MRI may temporarily maintain their cognitive status through the mobilization of their cognitive reserve, but will eventually develop subtle cognitive deficits.

Previous research done with positron emission tomography (PET), the current gold standard for brain metabolism imaging, found that patients with Alzheimer's disease had reduced metabolism in the same area of the brain where the perfusion abnormalities were found using ASL MRI. This points to a close link between brain metabolism and perfusion, according to Dr. Haller.

ASL MRI has potential as a standalone test or as an adjunct to PET for dementia screening, Dr. Haller said. While PET can identify markers of Alzheimer's disease in the brain and cerebrospinal fluid, it exposes the patient to radiation. ASL does not expose the patient to radiation and is easy to perform in routine clinical settings.

"ASL might replace the classic yet unspecific fluordesoxyglucose PET that measures brain metabolism. Instead, PET could be done with the new and specific amyloid PET tracers," Dr. Haller said.

The results also support a role for ASL MRI as an alternative to neuropsychological testing.

The researchers plan to perform follow-up studies on the patient group to learn more about ASL and long-term cognitive changes.

###

"Arterial Spin Labeling May Contribute to the Prediction of Cognitive Deterioration in Healthy Elderly Individuals." Collaborating with Dr. Haller were Aikaterini Xekardaki, M.D., Cristelle Rodriguez, M.Sc., Marie-Louise Montandon, Ph.D., Simona Toma, M.Sc., Eline Tombeur, B.Sc., François R. Herrmann, M.D., Dina Zekry, M.D., Karl-Olof Lovblad, M.D., Frederik Barkhof, M.D., and Panteleimon Giannakopoulos, 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 of the brain, visit RadiologyInfo.org.

Linda Brooks | Eurek Alert!

More articles from Health and Medicine:

nachricht Penn studies find promise for innovations in liquid biopsies
30.03.2017 | University of Pennsylvania School of Medicine

nachricht 'On-off switch' brings researchers a step closer to potential HIV vaccine
30.03.2017 | University of Nebraska-Lincoln

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

'On-off switch' brings researchers a step closer to potential HIV vaccine

30.03.2017 | Health and Medicine

Penn studies find promise for innovations in liquid biopsies

30.03.2017 | Health and Medicine

An LED-based device for imaging radiation induced skin damage

30.03.2017 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>