Human and nonhuman primate meninges harbor lymphatic vessels that can be visualized noninvasively by MRI

TLDR

The study demonstrates that meningeal lymphatic vessels exist in humans and nonhuman primates and can be mapped noninvasively in vivo using high‑resolution clinical MRI. Using T2‑FLAIR and T1‑weighted black‑blood imaging, gadobutrol contrast highlights these vessels—owing to its extravasation across permeable capillaries—while gadofosveset does not, and the vessels’ topography mirrors that of rodent meningeal lymphatics. Immunohistochemistry confirms that primate meningeal lymphatics express canonical lymphatic endothelial markers, underscoring their potential relevance for CNS lymphatic physiology and disease.

Abstract

Here, we report the existence of meningeal lymphatic vessels in human and nonhuman primates (common marmoset monkeys) and the feasibility of noninvasively imaging and mapping them in vivo with high-resolution, clinical MRI. On T2-FLAIR and T1-weighted black-blood imaging, lymphatic vessels enhance with gadobutrol, a gadolinium-based contrast agent with high propensity to extravasate across a permeable capillary endothelial barrier, but not with gadofosveset, a blood-pool contrast agent. The topography of these vessels, running alongside dural venous sinuses, recapitulates the meningeal lymphatic system of rodents. In primates, meningeal lymphatics display a typical panel of lymphatic endothelial markers by immunohistochemistry. This discovery holds promise for better understanding the normal physiology of lymphatic drainage from the central nervous system and potential aberrations in neurological diseases.