Scientists have developed a non-invasive MRI technique that measures brain iron levels, potentially identifying individuals at higher risk for Alzheimer’s disease years before symptoms manifest.
Researchers at Johns Hopkins University have unveiled a novel MRI technique that may serve as an early warning system for Alzheimer’s disease by measuring iron levels in the brain. This non-invasive method, known as quantitative susceptibility mapping (QSM), could help identify patients at a heightened risk of developing the disease long before any cognitive symptoms appear.
High levels of iron in the brain have been linked to increased brain toxins and neurodegeneration, which can lead to cognitive decline. This is particularly concerning when iron interacts with the abnormal amyloid and tau proteins, which are characteristic of Alzheimer’s pathology. The findings suggest that monitoring brain iron levels could provide crucial insights into an individual’s risk of developing mild cognitive impairment (MCI), a common precursor to Alzheimer’s dementia.
“QSM is an advanced MRI technique developed over the last decade to measure tissue magnetic susceptibility with good precision,” said Xu Li, the study’s senior author and an associate professor of radiology at Johns Hopkins University. “QSM can detect small differences in iron levels across different brain regions, providing a reliable and non-invasive way to map and quantify iron in patients, which is not possible with conventional MR approaches.”
In comparison to traditional imaging methods for Alzheimer’s diagnosis, such as PET scans, QSM MRI is not only non-invasive but also more affordable. This affordability could enhance accessibility for patients and healthcare providers alike, potentially allowing for earlier interventions.
The study, published in the journal *Radiology*, involved 158 cognitively unimpaired participants from a previous research project. After a follow-up period of seven and a half years, the researchers found that elevated iron levels in two critical brain regions were associated with a significantly higher risk of MCI. These regions, the entorhinal cortex and putamen, are closely linked to memory and learning.
“The key takeaway of our study is that higher brain iron levels, especially in some critical brain regions related to memory and learning, are linked to a two to four times higher risk of developing MCI and faster cognitive decline,” Li explained. “Such brain iron changes may be measured years before memory loss, when the participants are still cognitively normal.”
Li emphasized the importance of these findings, noting that the risk of cognitive impairment is even greater in individuals with elevated levels of amyloid pathologies. However, he acknowledged some limitations in the study, particularly the demographic composition of the participant group, which primarily consisted of White, highly educated individuals with a strong family history of Alzheimer’s disease.
If future studies with larger and more diverse populations confirm these results, it could pave the way for broader applications of QSM in clinical settings, particularly for patients at increased risk of dementia. “I think we should be hopeful,” Li said. “We can use this kind of tool to help identify patients at higher risk of developing Alzheimer’s disease and potentially guide early interventions as new treatments become available.”
Li also mentioned that while brain iron is associated with neurodegeneration, it plays an essential role in cognitive health and neurodevelopment, especially in younger individuals. Although iron chelation therapies aimed at reducing iron levels in the brain are currently being explored for Alzheimer’s treatment, their efficacy remains unclear, necessitating further research.
The researchers aim to enhance the standardization, speed, and accessibility of QSM technology in clinical practice, which could ultimately benefit many individuals at risk for Alzheimer’s disease.
Source: Original article