Signal Intensity of the Cerebrospinal Fluid after Intravenous Administration of Gadolinium-based Contrast Agents: Strong Contrast Enhancement around the Vein of Labbe

Abstract

Purpose: Since the first report on the deposition of gadolinium in the brain parenchyma after repeated intravenous administrations of gadolinium-based contrast agent GBCA (IV-GBCA), the mechanisms of penetration and retention are still remaining a hot topic of discussion and a target of investigation. We routinely obtain endolymphatic hydrops (EH) images at 4 h after IV administration of a single dose (SD) of GBCA (IV-SD-GBCA) using heavily T₂-weighted three-dimensional fluid-attenuated inversion recovery imaging (hT₂W-3D-FLAIR). Occasionally, we have encountered cases, which indicate high-signal intensity (SI) in the cerebrospinal fluid (CSF) surrounding the vein of Labbe. The purpose of the present study was to investigate the degree of contrast enhancement of the CSF surrounding the vein of Labbe on hT₂W-3D-FLAIR after IV-SD-GBCA in comparison with other CSF spaces.

Materials and methods: In 25 patients with a suspicion of EH, a magnetic resonance cisternography (MRC) and an hT₂W-3D-FLAIR were obtained at 4 h after IV-SD-GBCA. The perivascular space (PVS) in the basal ganglia, CSF spaces in the ambient cistern (CSF-Amb), the CSF surrounding the superficial middle cerebral vein (CSF-SMCV), and the CSF surrounding the vein of Labbe (CSF-VL) were segmented on MRC. The PVS and CSF regions were co-registered onto the hT₂W-3D-FLAIR and the SI of the PVS and CSF spaces were measured. The SI ratio (SIR) of the post-contrast hT₂W-3D-FLAIR to the pre-contrast hT₂W-3D-FLAIR was measured. Significant differences were evaluated using Steel-Dwass's test for multiple comparisons.

Results: The SIR of the CSF-VL was significantly higher than that of the PVS (P = 0.008), the CSF-Amb (P = 0.021), and the CSF-SMCV (P = 0.023).

Conclusion: The strong contrast enhancement of CSF space around the vein of Labbe was confirmed on hT₂W-3D-FLAIR at 4 h after IV-GBCA compared to the PVS and the other CSF spaces.

Keywords: cerebrospinal fluid; gadolinium; glymphatic system; magnetic resonance imaging; vein.

Fig. 1

An example of segmentation of the perivascular space (PVS) in the basal ganglia for the signal intensity measurement. The PVS region was segmented using a region-growing method on the magnetic resonance cisternography.

Fig. 2

An example of segmentation of the cerebrospinal fluid (CSF) spaces for the signal intensity measurement. Circular ROIs with a 6 mm diameter were placed in the ambient cistern (a), the superficial middle cerebral vein (SMCV) (b), and vein of Labbe (c) on the magnetic resonance cisternography. To exclude the vessels, bones, or brain parenchyma from the ROIs, the CSF regions within the ROIs in the ambient cistern (d), surrounding SMCV (e), and surrounding the vein of Labbe (f) were segmented using the region growing method.

Fig. 3

A comparison of the signal intensity ratio (SIR) of the perivascular space (PVS) in the basal ganglia and the cerebrospinal fluid (CSF) spaces. An asterisk indicates the statistically significant difference. The SIR of the CSF surrounding the vein of Labbe (CSF-VL) was increased significantly compared to that of the PVS, the CSF in the ambient cistern (CSF-Amb), and the CSF surrounding the superficial middle cerebral vein (CSF-SMCV).

Fig. 4

A representative image: a 56-year-old woman with clinical suspicion of endolymphatic hydrops. (a) A magnetic resonance cisternography as anatomical reference for the fluid space. (b) A heavily T₂-weighted 3D fluid-attenuated inversion recovery image (hT₂W-3D-FLAIR) obtained before administration of the contrast agent. (c) A hT₂W-3D-FLAIR obtained at 4 h after administration of the contrast agent. The cerebrospinal fluid (CSF) surrounding the vein of Labbe indicates higher signal intensity than the other CSF spaces (arrows).