Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


MRI shows gray matter myelin loss strongly related to MS disability


People with multiple sclerosis (MS) lose myelin in the gray matter of their brains and the loss is closely correlated with the severity of the disease, according to a new magnetic resonance imaging (MRI) study. Researchers said the findings could have important applications in clinical trials and treatment monitoring. The study appears online in the journal Radiology.

Loss of myelin, the fatty protective sheath around nerve fibers, is a characteristic of MS, an inflammatory disease of the central nervous system that can lead to a variety of serious neurological symptoms and disability.

The scheme demonstrating how an MPF map is computed from source MR images. Imaging protocol includes three gradient-echo images with variable flip angles, a gradient-echo image with off-resonance radiofrequency saturation enabling the magnetization transfer effect (MT-weighted image), and a reference image that is a similar gradient-echo image obtained without saturation. Additionally, an MR imager produces maps of the main magnetic field (B0) and radiofrequency field (B1), which are used to correct errors caused by imperfectness of imager's hardware. MPF maps are computed voxel-by-voxel in two steps, (A) and (B), using special software developed by the authors. During the first step (A), a map of the longitudinal relaxation rate (R1) is generated as described in the literature. This map along with an MT-weighted image and a reference image are used to compute an MPF map in the second step (B) based on an iterative algorithm recently described by the authors.

Credit: Radiological Society of North America

MS is typically considered a disease of the brain's signal-conducting white matter, where myelin is most abundant, but myelin is also present in smaller amounts in gray matter, the brain's information processing center that is made up primarily of nerve cell bodies.

Though the myelin content in gray matter is small, it is still extremely important to proper function, as it enables protection of thin nerve fibers connecting neighboring areas of the brain cortex, according to Vasily L. Yarnykh, Ph.D., associate professor in the Department of Radiology at University of Washington in Seattle.

... more about:
»MRI »MS »RRMS »Radiological »disability »spinal

"The fact that MS patients lose myelin not only in white but also in gray matter has been proven by earlier post-mortem pathological studies," he said. "However, the clinical significance of the myelin loss, or demyelination, in gray matter has not been established because of the absence of appropriate imaging methods."

To learn more about associations between MS and demyelination in both white and gray matter, Dr. Yarnykh and colleagues used a refined MRI technique that provides information on the content of biological macromolecules – molecules present in tissues and composed of a large number of atoms, such as proteins, lipids and carbohydrates. The new method, known as macromolecular proton fraction (MPF) mapping, has been hampered in the past because of the length of time required for data collection, but improvements now allow much faster generation of whole-brain maps that reflect the macromolecular content in tissues.

"The method utilizes a standard MRI scanner and doesn't require any special hardware—only some software modifications," Dr. Yarnykh said. "MPF mapping allows quantitative assessment of microscopic demyelination in brain tissues that look normal on clinical images, and is the only existing method able to evaluate the myelin content in gray matter."

The researchers looked at 30 MS patients, including 18 with relapsing-remitting MS (RRMS), the most common type of MS initially diagnosed, and 12 with the more advanced type of disease known as secondary progressive MS (SPMS). Fourteen healthy control participants were also included in the study. Each participant underwent MRI on a 3-Tesla imager, and the researchers reconstructed 3-D whole-brain MPF maps to look at normal-appearing white matter, gray matter and MS lesions. The researchers further compared the results of their imaging technique with clinical tests characterizing neurological dysfunction in MS patients.

The results showed that MPF was significantly lower in both white and gray matter in RRMS patients compared with healthy controls, and was also significantly reduced in both normal-appearing brain tissues and lesions of SPMS patients compared to RRMS patients with the largest relative decrease in gray matter. MPF in brain tissues of MS patients significantly correlated with clinical disability and the strongest associations were found for gray matter.

"The major finding of the study is that the loss of myelin in gray matter caused by MS in its relative amount is comparable to or even larger than that in white matter," said Dr. Yarnykh. "Furthermore, gray matter demyelination is much more advanced in patients with secondary-progressive MS, and it is very strongly related to patients' disability. As such, we believe that information about gray matter myelin damage in MS is of primary clinical relevance."

The improved technique has potentially important applications for MS treatments targeted to protect and restore myelin.

"First, this method may provide an objective measure of the disease progression and treatment success in clinical trials," Dr. Yarnykh said. "And second, assessment of both gray and white matter damage with this method may become an individual patient management tool in the future."

Dr. Yarnykh and colleagues are currently conducting additional research on the new method with the support of the National Multiple Sclerosis Society and the National Institutes of Health.

"This study was done on the participants at a single point in time," he said. "Now we want to compare MS patients with control participants to see how myelin content will evolve over time. We further plan to extend our method to the spinal cord imaging and test whether the combined assessment of demyelination in the brain and spinal cord could better explain disability progression as compared to brain demyelination alone."


"Fast Whole-Brain Three-dimensional Macromolecular Proton Fraction Mapping in Multiple Sclerosis." Collaborating with Dr. Yarnykh were James D. Bowen, M.D., Alexey Samsonov, Ph.D., Pavle Repovic, M.D., Angeli Mayadev, M.D., Peiqing Qian, M.D., Beena Gangadharan, Ph.D., Bart P. Keogh, M.D., Ph.D., Kenneth R. Maravilla, M.D., and Lily K. Jung Henson, 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

Linda Brooks | Eurek Alert!

Further reports about: MRI MS RRMS Radiological disability spinal

More articles from Medical Engineering:

nachricht Gentle sensors for diagnosing brain disorders
29.09.2016 | King Abdullah University of Science and Technology

nachricht New imaging technique in Alzheimer’s disease - opens up possibilities for new drug development
28.09.2016 | Lund University

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Oasis of life in the ice-covered central Arctic

24.10.2016 | Earth Sciences

‘Farming’ bacteria to boost growth in the oceans

24.10.2016 | Life Sciences

Light-driven atomic rotations excite magnetic waves

24.10.2016 | Physics and Astronomy

More VideoLinks >>>