Human and nonhuman primate meninges harbor lymphatic vessels that can be visualized noninvasively by MRI.
Level 4 - case-series / case-control
Descriptive human and primate imaging series with histological validation
PubMed 28971799 · doi:10.7554/eLife.29738
What was done
Researchers evaluated the presence and structure of meningeal lymphatic vessels in humans and nonhuman primates (common marmoset monkeys) using high-resolution clinical MRI. In vivo noninvasive mapping was performed using T2-FLAIR and T1-weighted black-blood sequences with two contrast agents: gadobutrol (extravasating gadolinium agent) and gadofosveset (blood-pool agent). MRI findings were corroborated by immunohistochemistry for lymphatic endothelial markers.
What was found
No numerical results, sample sizes, or quantitative metrics were reported in the abstract. Meningeal lymphatic vessels were visualized running alongside dural venous sinuses in both humans and nonhuman primates, recapitulating rodent topography. These structures demonstrated enhancement with gadobutrol but not with gadofosveset and expressed lymphatic endothelial markers on immunohistochemistry.
Why it matters
This work confirms that meningeal lymphatic networks are present in primates and can be mapped in vivo with conventional MRI contrast agents, providing a tool to study CNS fluid clearance and lymphatic pathology in human neurological disease.
Limits
The abstract reports no participant or animal sample sizes, no quantitative measurements, and no performance characteristics or reliability metrics for the MRI protocol. Functional clearance dynamics and disease associations were not evaluated.
Cited by
- supports Roughly 20 years ago, researchers discovered tiny meningeal lymphatic vessels penetrating the dura around the brain, disproving the longstanding medical belief that the brain is isolated from the immune and lymphatic systems.