The Mesoscopic Scale.
Mesoscopic vessels (meso-vessels) occupy the critical transition zone between macro-anatomy and micro-anatomy. These veins and arteries are too small to be named in standard medical atlases, yet large enough to be resolved using magnetic resonance imaging (MRI).
I consider the mesoscopic scale as above 0.1 mm and below 0.5 mm in at least two spatial imaging dimensions. However, the term is frequently extended in contemporary literature to encompass the broader submillimeter range (<1 mm).
This archive focuses on in vivo human brain imaging. While the principles of meso-vessels extend across species, the content curated here is primarily centered on human neuroimaging research and the specific technical challenges of resolving architecture within the living human cortex.
Vessel Classification
While macroscopic vessels handle bulk transport, mesoscopic vasculature is where the actual physiological exchange begins to take shape. Mapping these structures is vital for understanding neurovascular coupling and cerebral hemodynamics at currently accessible and practical human brain functional imaging resolutions.
Cerebral vessels form an intricate, space-filling network with diverse connectivity patterns. To disentangle this complexity, I use the Duvernoy & Vannson (1999) framework for vessel categorization:
- LEPTOMENINGEAL: Large vessels coursing through the subarachnoid space.
- PIAL: Vessels adhering closely to the cortical surface.
- INTRACORTICAL: Trunks descending/ascending through gray matter and their capillary interconnections. Sometimes the trunks are referred to arterioles and venules in the literature.
The leptomeningeal-pial-intracortical hierarchy is secondary to the primary physiological divide: arterial vessels, which deliver blood to the brain, and venous vessels, which drain blood away from the brain.
Inspirations.
These blogs have been foundational in defining my look at the current brain imaging landscape:
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layerfmri.com
The beating heart of the layer-fMRI community, essential resources, tips, and tricks for high resolution imaging.
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practicalfmri.blogspot.com
Education, tips and tricks to help you conduct better fMRI experiments. Fixing the acquisition is always better than fixing it in processing.
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thebrainblog.org
Collection of thoughts and perspectives on brain imaging and assessment, from methodological details to speculative opinion.
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BrainVoyager Blog
Posts on algorithm implementation details and new computer graphics features in BrainVoyager software.
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thingsonthings.org
My first blog that ended up being mostly about geometry processing algorithms implemented in LayNii.
The Author.
I am a scientist focused on the mesoscopic architecture of the human brain: https://ofgulban.github.io.
My work sits at the edge of what is visible, using magnetic resonance imaging (MRI) to study the geometry of the brain vessels.
This site serves as my digital archive. A place to document the visual and technical progress of meso-vessel imaging.
KEYWORDS: Brain Imaging, MRI, 7 Tesla, LayNii, Cortex, Subcortex, Human, Anatomical, Functional, Cortex, Geometry