Gadolinium and Multiple Sclerosis: Vessels, Barriers of the Brain, and Glymphatics.

C Saade,D.M Yousem,K Asmar,L Naffaa,R Bou-Fakhredin,F El-Merhi

doi:10.3174/ajnr.a5773

Abstract

The pathogenesis of multiple sclerosis is characterized by a cascade of pathobiologic events, ranging from focal lymphocytic infiltration and microglia activation to demyelination and axonal degeneration. MS has several of the hallmarks of an inflammatory autoimmune disorder, including breakdown of the BBB. Gadolinium-enhanced MR imaging is currently the reference standard to detect active inflammatory lesions in MS. Knowledge of the patterns and mechanisms of contrast enhancement is vital to limit the radiologic differential diagnosis in the staging and evaluation of MS lesion activity. The aim of this review was the following: 1) to outline the pathophysiology of the effect of lymphocyte-driven inflammation in MS, 2) to describe the effects of gadolinium on the BBB and glymphatic system, and 3) to describe gadolinium enhancement patterns and artifacts that can mimic lesions in MS.

Highlights

Particular to arteries, pulsation that is often generated by the postcontrast FLAIR image, the subarachnoid and perivascular spaces showed increased signal intensity, subsequent to Gd3ϩ transfer to the subarachnoid and perivascular spaces. These results demonstrate that intravenously administered Gd3ϩ can be transported through the glymphatic system to reach the brain
This method will provide a clear pathway for the paravascular space in the Enhancement Patterns and Lesion Characteristics glymphatic system that could be detected by different imaging The cause of the enhancement in MS is inflammation, which most techniques.[43]
The advent of FLAIR scanning has nearly eliminated any confusion between perivascular spaces which, like CSF, are dark on FLAIR scans, versus MS plaques, which are bright on FLAIR

Summary

Gadolinium Effects

This method will provide a clear pathway for the paravascular space in the Enhancement Patterns and Lesion Characteristics glymphatic system that could be detected by different imaging The cause of the enhancement in MS is inflammation, which most techniques.[43] Studies have shown that tracers injected into the paravascular space are only evident along the arteries and not veins and are characterized as being bidirectional, depending of the site of injection. One possible mechanism of damage to the WM is through the involvement of a cerebral venule or an arteriole, which provides the blood supply of the parenchyma that depends on the vasculature.[56] White matter microvascular disease involves a broad range of conditions such as infection, hypoxia-ischemia, atherosclerosis, granulomatous or nongranulomatous inflammation, among others It can manifest as focal lesions in the WM or in paravascular spaces. The confluence of these lesions makes up a ridgelike configuration, which is associated with MS.[56]

Localization of an isolated lesion of

CONCLUSIONS