Assessment of Meningeal Lymphatics in the Parasagittal Dural Space: A Prospective Feasibility Study Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging
Bio Joo, Mina Park, Sung Jun Ahn, Sang Hyun Suh
Abstract
Objective: Meningeal lymphatic vessels are predominantly located in the parasagittal dural space (PSD); these vessels drain interstitial fluids out of the brain and contribute to the glymphatic system.We aimed to investigate the ability of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing the dynamic changes in the meningeal lymphatic vessels in PSD.Materials and Methods: Eighteen participants (26-71 years; male:female, 10:8), without neurological or psychiatric diseases, were prospectively enrolled and underwent DCE-MRI.Three regions of interests (ROIs) were placed on the PSD, superior sagittal sinus (SSS), and cortical vein.Early and delayed enhancement patterns and six kinetic curve-derived parameters were obtained and compared between the three ROIs.Moreover, the participants were grouped into the young (< 65 years; n = 9) or older ( 65 years; n = 9) groups.Enhancement patterns and kinetic curve-derived parameters in the PSD were compared between the two groups. Results:The PSD showed different enhancement patterns than the SSS and cortical veins (P < 0.001 and P < 0.001, respectively) in the early and delayed phases.The PSD showed slow early enhancement and a delayed wash-out pattern.The six kinetic curve-derived parameters of PSD was significantly different than that of the SSS and cortical vein.The PSD washout rate of older participants was significantly lower (median, 0.09; interquartile range [IQR], 0.01-0.15)than that of younger participants (median, 0.32; IQR, 0.07-0.45)(P = 0.040). Conclusion:This study shows that the dynamic changes of meningeal lymphatic vessels in PSD can be assessed with DCE-MRI, and the results are different from those of the venous structures.Our finding that delayed wash-out was more pronounced in the PSD of older participants suggests that aging may disturb the meningeal lymphatic drainage.