Nav: Home

Diattenuation imaging -- a promising imaging technique for brain research

March 19, 2019

A new imaging method provides structural information about brain tissue that was previously difficult to access. Diattenuation Imaging (DI), developed by scientists at Forschungszentrum Jülich and the University of Groningen, allows to differentiate, e.g., regions with many thin nerve fibres from regions with few thick nerve fibres. With current imaging methods, these tissue types cannot easily be distinguished.

The DI method is based on 3D Polarized Light Imaging (3D-PLI), a neuroimaging technique developed at Forschungszentrum Jülich, which reveals nerve fibre pathways with micrometre resolution. 3D-PLI is used, for instance, in the European Human Brain Project to investigate the 3D fibre structures of the brain in unprecedented detail.

During a 3D-PLI measurement, histological brain sections are illuminated with polarized light. Depending on how the direction of oscillation (polarization) is oriented relative to the nerve fibres, the light is refracted to different degrees, allowing to compute the spatial orientation of the nerve fibres. This effect - called birefringence - is mainly caused by the myelin sheath, an insulating layer which surrounds many nerve fibres in the brain.

While 3D-PLI measures the polarization-dependent refraction of light, a diattenuation measurement determines the polarization-dependent attenuation of light, i.e. how much the intensity of polarized light is reduced when passing through the brain section. The measurement is performed with the same apparatus as 3D-PLI, whereby two filters are removed.

The scientists have discovered that Diattenuation Imaging - a combined measurement of diattenuation and 3D-PLI - allows to distinguish between different brain regions. In some regions, the brain tissue is maximally transparent when the polarization of the light is oriented parallel to the nerve fibres. In other regions, the tissue is maximally transparent when the polarization is oriented perpendicularly to the nerve fibres. How the tissue behaves depends, among other things, on the time after embedding the brain sections.

Using simulations on the former Jülich supercomputer JUQUEEN, the researchers could show that the observed effects also depend on other tissue properties like the diameter of the fibres or the thickness of the myelin sheaths. This makes Diattenuation Imaging a valuable extension to 3D-PLI, enabling a more precise investigation of brain tissue. In the future, the DI method could be used to study neurodegenerative diseases like multiple sclerosis or multisystem atrophy (MSA), which go along with alterations of the myelin sheath. In addition, the technology helps to make pathological changes visible and to identify connected regions and tissue types, assisting the complex reconstruction of the brain.
-end-


Forschungszentrum Juelich

Related Brain Articles:

Transplanting human nerve cells into a mouse brain reveals how they wire into brain circuits
A team of researchers led by Pierre Vanderhaeghen and Vincent Bonin (VIB-KU Leuven, Université libre de Bruxelles and NERF) showed how human nerve cells can develop at their own pace, and form highly precise connections with the surrounding mouse brain cells.
Brain scans reveal how the human brain compensates when one hemisphere is removed
Researchers studying six adults who had one of their brain hemispheres removed during childhood to reduce epileptic seizures found that the remaining half of the brain formed unusually strong connections between different functional brain networks, which potentially help the body to function as if the brain were intact.
Alcohol byproduct contributes to brain chemistry changes in specific brain regions
Study of mouse models provides clear implications for new targets to treat alcohol use disorder and fetal alcohol syndrome.
Scientists predict the areas of the brain to stimulate transitions between different brain states
Using a computer model of the brain, Gustavo Deco, director of the Center for Brain and Cognition, and Josephine Cruzat, a member of his team, together with a group of international collaborators, have developed an innovative method published in Proceedings of the National Academy of Sciences on Sept.
BRAIN Initiative tool may transform how scientists study brain structure and function
Researchers have developed a high-tech support system that can keep a large mammalian brain from rapidly decomposing in the hours after death, enabling study of certain molecular and cellular functions.
Wiring diagram of the brain provides a clearer picture of brain scan data
In a study published today in the journal BRAIN, neuroscientists led by Michael D.
Blue Brain Project releases first-ever digital 3D brain cell atlas
The Blue Brain Cell Atlas is like ''going from hand-drawn maps to Google Earth'' -- providing previously unavailable information on major cell types, numbers and positions in all 737 brain regions.
Landmark study reveals no benefit to costly and risky brain cooling after brain injury
A landmark study, led by Monash University researchers, has definitively found that the practice of cooling the body and brain in patients who have recently received a severe traumatic brain injury, has no impact on the patient's long-term outcome.
Brain cells called astrocytes have unexpected role in brain 'plasticity'
Researchers from the Salk Institute have shown that astrocytes -- long-overlooked supportive cells in the brain -- help to enable the brain's plasticity, a new role for astrocytes that was not previously known.
Largest brain study of 62,454 scans identifies drivers of brain aging
In the largest known brain imaging study, scientists from Amen Clinics (Costa Mesa, CA), Google, John's Hopkins University, University of California, Los Angeles and the University of California, San Francisco evaluated 62,454 brain SPECT (single photon emission computed tomography) scans of more than 30,000 individuals from 9 months old to 105 years of age to investigate factors that accelerate brain aging.
More Brain News and Brain Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.