Abstract

How can sodium MRI techniques help us understand acute stroke?

Author(s): Andrew J Fagan

This article addresses the potential usefulness of sodium MRI in the acute phase of stroke, asking whether the additional time required to acquire high-quality sodium images is justified in the time-critical minutes following the presentation of a patient with stroke symptoms. It begins with a description of the pathophysiology of stroke and the implications of the increasing bioenergetic failure on the sodium content in tissue. Recent studies that have aimed at imaging the subtle changes in this sodium content in stroke patients are then reviewed, followed by experiments in animal models of stroke, which circumvent some of the limitations of the human studies. Finally, steps that will probably be required to translate these latest model findings into human studies are discussed, including new MRI techniques that may provide a boost in signal and allow for the introduction of relaxation-time contrast and quantification of the sodium concentration.