Iron load on imaging could signal impending cognitive decline in asymptomatic patients
Researchers have gained new insight into how iron levels in the brain impact cognitive function.
That’s thanks to an MRI technique called quantitative susceptibility mapping (QSM), which can measure tissue susceptibility and detect subtle variances in iron levels throughout different regions of the mind.
In recent years, iron overload has caught the attention of experts due to its ability to induce oxidative stress. This can contribute to cognitive decline by aggravating amyloid toxicity and promoting cell death. The ability to quantify iron levels via imaging could help identify patients who may be vulnerable to cognitive decline in the future, even before they display symptoms.
“Elevated brain iron is a potential marker for neurodegeneration, but its role in predicting onset of mild cognitive impairment (MCI) and prospective cognitive trajectories remains unclear,” Xu Li, PhD, associate professor of radiology at Johns Hopkins University, and colleagues wrote in RSNA’s flagship journal Radiology.
The team analyzed the QSM MR imaging of 158 cognitively unimpaired individuals, 110 of whom also had available PET imaging. More than seven years of follow-up data were available for the team to examine as well. Researchers assessed patients’ baseline tissue susceptibility on imaging, comparing it to their time to MCI onset and changes in cognitive scores over time.
The group observed associations between higher baseline magnetic susceptibility on MRI in the entorhinal cortex and putamen and the risk of MCI. Both these regions of the brain are known to be associated with memory and different aspects of cognitive function. This finding was consistent in both the MRI group and the PET subgroup. However, in the PET subgroup, the finding correlated with greater global cognitive decline, particularly in those who also displayed amyloid abnormalities on imaging.
If confirmed in further studies, the group is hopeful their findings have the potential to contribute to the development of iron-targeted therapies.
“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 said. “Also, besides serving as a biomarker, brain iron may become a future therapeutic target.”
Read more about the study here.
In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.