New imaging technique may facilitate future diagnosis of concussion via MRI

By Camila Smith-Donald. This article was initially published in the 2/1/24 edition of our Concussion Update newsletter; please consider subscribing.

In a recent study, Lily Li-Wen Wang et al. found that macrophage-adhering GLAMs can be used to identify the presence of mild traumatic brain injuries (mTBIs) that do not show up on standard MRI brain scans. GLAMs (gadolinium-loaded anisotropic micropatches) are made of standard MRI contrast agents (gadolinium) combined with immune cells called macrophages. Macrophages naturally target areas of inflammation, allowing GLAMs to highlight damage in the brain that would go undetected on a standard MRI.

This development, published in Science Translational Medicine, is welcome in a field where accurate diagnosis has been a longtime difficulty; currently, as many as 90% of mTBI cases may go undiagnosed, according to an article by Lindsay Brownell published by the Wyss Institute. GLAMs take advantage of changes caused by mTBI in the choroid plexus, the brain area that regulates the entry of white blood cells (like macrophages) into the brain through the blood-brain barrier. When GLAMs are injected into the bloodstream of a potential mTBI patient, they will pass through the blood-brain barrier to target sites of damage, where they will then show up on MRI scans. 

So far, the GLAMs have been tested in mice and pigs, with promising results. In addition to their imaging advantages, GLAMs appear safer for the kidneys than other gadolinium-based imaging agents and require a much lower dosage to be effective. Although this imaging strategy is much better at identifying when there is inflammation, it does not provide spatial specificity in locating areas of neuronal damage after mTBI.