Evaluation of glymphatic-meningeal lymphatic system with intravenous gadolinium-based contrast-enhancement in cerebral small-vessel disease

ObjectiveTo investigate the feasibility of using noninvasive neuroimaging methods in visualizing and evaluating the clearance of the glymphatic-meningeal lymphatic system (GMLS) in patients with arteriosclerotic cerebral small-vessel disease (CSVD) and controls.MethodsThis observational study recruited patients with high-burden CSVD and controls (age 50-80 years). At multiple time points before and after intravenous administration of a contrast agent, three-dimensional (3D) brain volume T1-weighted imaging and 3D Cube T2-fluid attenuated inversion recovery imaging were performed to visualize and assess the clearance of the glymphatics and meningeal lymphatic vessels (mLVs). We measured the signal intensity ratio (SIR) of four regions of interest representing the glymphatics and mLVs at each time point. The clearance rate at 24 h (CR24h) and changes in the SIR from baseline to 24 h ( increment SIR) were defined as the clearance function. The analysis of variance was used to evaluate the group differences after adjusting for hypertension.ResultsA total of 20 CSVD patients and 15 controls were included. Cortical periarterial enhancement and the enhancement of enlarged perivascular spaces in the basal ganglia were respectively observed in 11 (55.00%) and 16 (80.00%) CSVD patients, but in none of controls. All CSVD patients and most of controls (80.00%) showed cortical perivenous enhancement. Para-sinus enhancement was observed in all participants. CSVD patients showed lower CR24h and higher increment SIR of the glymphatics and mLVs (all p < 0.05).ConclusionThe impaired drainage of the GMLS in patients with high-burden CSVD could be visually evaluated using noninvasive neuroimaging methods with intravenous gadolinium-based contrast-enhancement.