Association between the Putative Meningeal Lymphatics at the Posterior Wall of the Sigmoid Sinus and Delayed Contrast-agent Elimination from the Cerebrospinal Fluid

Abstract

To investigate the characteristics of the putative meningeal lymphatics located at the posterior wall of the sigmoid sinus (PML-PSS) in human subjects imaged before and after intravenous administration (IV) of a gadolinium-based contrast agent (GBCA). The appearance of the PML-PSS and the enhancement of the perivascular space of the basal ganglia (PVS-BG) were analyzed for an association with gender, age, and clearance of the GBCA from the cerebrospinal fluid (CSF).Methods: Forty-two patients with suspected endolymphatic hydrops were included. Heavily T2-weighted 3D-fluid attenuated inversion recovery (hT2w-3D-FLAIR) and 3D-real inversion recovery (IR) images were obtained at pre-administration, immediately post-administration, and at 4 and 24 hours after IV-GBCA. The appearance of the PML-PSS and the presence of enhancement in the PVS-BG were analyzed for a relationship with age, gender, contrast enhancement of the CSF at 4 hours after IV-GBCA, and the washout ratio of the GBCA in the CSF from 4 to 24 hours after IV-GBCA. Results:The PML-PSS and PVS-BG were seen in 23 of 42 and 21 of 42 cases, respectively, at 4 hours after IV-GBCA. In all PML-PSS positive cases, hT2w-3D-FLAIR signal enhancement was highest at 4 hours after IV-GBCA. A multivariate analysis between gender, age, CSF signal elevation at 4 hours, and washout ratio indicated that only the washout ratio was independently associated with the enhancement of the PML-PSS or PVS-BG. The odds ratios (95% CIs; P value) were 4.

Diffusion Tensor Image Analysis ALong the Perivascular Space (DTI-ALPS): Revisiting the Meaning and Significance of the Method

“…The study also simultaneously examined the enhancement of the basal ganglia perivascular space (PVS-BG), and PVS-BG was seen in 21 of the 42 cases. 114 , 115 …”

“…The study also simultaneously examined the enhancement of the basal ganglia perivascular space (PVS-BG), and PVS-BG was seen in 21 of the 42 cases. 114,115 There have been several trials using intravenous GBCA to assess the degree of leakage of the BBB. In a study that used a Patlak graphical approach to quantify BBB leakage rates and regional plasma volume on dynamic contrast images after intravenous GBCA injection, the volume fraction of brain tissue with GBCA leakage was significantly higher in AD.…”

Direct Visualization of Tracer Permeation into the Endolymph in Human Patients Using MR Imaging

“…13,21,24 The same ROI was copied and measured in other phases. 26 The signal intensity of the perilymph was measured as in the previous reports by manually encircling the scala tympani of the cochlear basal turn on the images taken 4h later and copying this ROI to other phases. If there was a positional shift between phases, the ROI was manually moved slightly as appropriate.…”

Glymphatic-lymphatic coupling: assessment of the evidence from magnetic resonance imaging of humans

“…Several reports of MRI studies claim to have directly visualized dural lymphatic vessels after administration of intravenous contrast [ 41 – 47 ], some with addition of the precautious prefix “putative” [ 47 ]. Typically, single, mm-thick tubular structures are demonstrated in 2D or 3D and conclusions about their lymphatic origin typically rely on a topography fitting with descriptions of dural lymphatic networks in rodents or neuropathological data.…”