Researchers at the University of Washington (Seattle, WA) used optical coherence tomography (OCT) to render high-resolution images and information about blood-flow dynamics over a broad region of the brain before, during, and after stroke-like states. The work could someday guide new treatments and reduce stroke-induced damage to the brain.
In the study, Ruikang Wang, Ph.D., professor of bioengineering and ophthalmology, and co-authors Utku Baran and Yuandong Li used OCT-based optical microangiography to reveal brain-vessel dynamics in tremendous detail during real-time experimental stroke.
Not only were the researchers able to achieve high-resolution images of in vivo vascular networks across a large area, but they also were able to evaluate the vessel diameters, red-blood-cell velocity, and total blood-flow change across the area. In doing so, Wang says, they demonstrated a biologically initiated rescue mechanism in response to stroke. The new information could potentially provide guidance to clinicians treating stroke patients.
|A comparison between regions where teriolo-arteriolar anastomosis (AAA) is relatively stronger or weaker. (Credit: Utku Baran, Yuandong Li, Ruikang Wang; http://dx.doi.org/10.1117/1.nph.2.2.025006)|
"Our key finding uncovers a non-uniform regulation event in penetrating arterioles—variance in the dilation among important vessels circulating blood throughout the brain," Wang says. "Specifically, active dilation of penetrating arterioles during stroke requires strong connections—anastomosis presence—and dilation and therefore blood flow fail in the areas farther away from an anastomosis. Abundance of anastomoses may prevent or delay permanent neural damage by supplying blood to penetrating arterioles and recovering rescuable tissue called penumbra."
With the enhanced imaging capability, Wang and his colleagues may discover as-yet-unknown mechanisms by which the brain regulates blood flow to brain tissue, says David Boas, editor-in-chief of the journal Neurophotonics, in which the study is published.
To read the study in Neurophotonics, please visit http://dx.doi.org/10.1117/1.nph.2.2.025006.
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