More available, more affordable and quicker
Small-angle X-ray scattering (SAXS) is a recognized approach in product science to look into how different structures are organized with a synchrotron, while diffusion magnetic resonance imaging (dMRI) is an important technique in centers for envisioning the three-dimensional nerve fiber network of the brain. “We have actually now shown that SLI data are consistent with those from SAXS and dMRI in the examined brain pieces, but SLI provides higher resolution than dMRI and is more available, more affordable and faster than the other strategies. This is a crucial milestone,” Menzel states. “We can perform SLI measurements with a simple LED light source and cam in simply a few seconds, needing neither a multi-million synchrotron nor an MRI scanner. As a portable system, it could easily be set up in pathology labs to assist medical research study.”
Tiny resolution
Menzel has spent the past few years dealing with the SLI strategy, first in Jülich and now in Delft. She likewise executed it in Stanford, where her fellow researchers carried out SAXS and dMRI measurements on brain samples also imaged with SLI. “Most imaging strategies have a hard time to recognize individual paths in thick brain structures containing numerous knotted or interwoven nerve fibers,” Menzel discusses. “SLI supplied fiber orientation maps with tiny resolution in these thick regions.” Especially the two-dimensional (” in-plane”) fiber orientations were determined with high precision.
Next steps
” Being in Delft brings interesting opportunities to develop the strategy even more and deal with brand-new applications,” says Menzel. The team plans to also use SLI to other types of fibers, such as muscle and collagen fibers, and to expand the tissue location that can be studied. The aim is to establish a portable and little system that can easily be released in other laboratories. “In the long term, we intend to use the strategy in centers as well.”
Recommendation: “Using light and X-ray scattering to untangle complex neuronal orientations and confirm diffusion MRI” by Miriam Menzel, David Gräßel, Ivan Rajkovic, Michael M Zeineh and Marios Georgiadis, 11 May 2023, eLife.DOI: 10.7554/ eLife.84024.
Disentangling the complex nerve fiber network of the brain is ending up being quickly available with scattered light imaging (SLI): researchers in Delft, Jülich (Germany), and Stanford (USA) successfully combined light and X-ray scattering with MRI to determine nerve fiber trajectories, likewise in regions with highly entangled fibers. Miriam Menzel, Assistant Professor at the Department of Imaging Physics of TU Delft, developed the SLI technique to study such fiber constellations: “We shine light under different angles through hair-thin brain slices and analyze the resulting scattering patterns. Small-angle X-ray scattering (SAXS) is an established approach in material science to look into how different structures are organized with a synchrotron, while diffusion magnetic resonance imaging (dMRI) is an essential technique in clinics for imagining the three-dimensional nerve fiber network of the brain. “Most imaging methods struggle to determine private paths in dense brain structures consisting of many entangled or interwoven nerve fibers,” Menzel explains. The group plans to likewise apply SLI to other types of fibers, such as muscle and collagen fibers, and to expand the tissue location that can be studied.
Color-coded nerve fiber orientations in a brain area acquired from spread light imaging (SLI, left) and small-angle X-ray scattering (SAXS, right). Credit: TU Delft
The Scattering Light Imaging (SLI) method provides a cost-effective, high-resolution approach to map neural connections in the brain The method, which includes evaluating light scattering patterns in thin brain slices, uses more detailed results than existing techniques like dMRI, and is more available and faster than SAXS.
Disentangling the complex nerve fiber network of the brain is becoming quickly available with scattered light imaging (SLI): scientists in Delft, Jülich (Germany), and Stanford (USA) successfully combined light and X-ray spreading with MRI to discern nerve fiber trajectories, also in regions with extremely knotted fibers. SLI exposed the trajectories at greatest detail, while being significantly quicker and less expensive than X-ray and MRI strategies. Such in-depth mapping is essential for a better understanding of how nerve fibers are wired inside the brain.
Paths in the brain.
The various locations in the brain are linked to each other via billions of nerve fibers. These connections are crucial for correct brain function. The mission for a thorough map of all neural connections critically depends on imaging strategies that can disentangle these fibers, many of them just about a micrometer thin. Particularly challenging are areas with extremely interwoven and largely jam-packed nerve fibers. Miriam Menzel, Assistant Professor at the Department of Imaging Physics of TU Delft, established the SLI method to study such fiber constellations: “We shine light under various angles through hair-thin brain pieces and evaluate the resulting scattering patterns. Were not taking a photo of nerve cells or synapses; we need to know how they are wired. This is essential for understanding brain function and dysfunction.”