Brain Nucleus Changes in Cognitive Disorders: Examining By the Quantitative Susceptibility Mapping (QSM) Technique

Iron deposition is vital for damaging neurons and causing different cognitive disorders. Today, using the quantitative susceptibility mapping (QSM) technique, iron deposits in other brain areas can be assessed and measured. This study aimed to identify changes in iron deposition of 12 brain nuclei through different stages of dementia using the QSM technique to introduce biomarkers for the early detection of cognitive disorders.
The Alzheimer’s Disease Neuroimaging Initiative (ADNI) database was used to download data. A 3T MRI scanner scanned thirty-five participants with normal cognition and forty-six patients with cognitive disorders who were classified into four groups based on the severity of the condition. QSM processing determined twelve regions of interest (ROIs) by automatic nuclei segmentation and statistical analysis performed in these groups’ MRI images.
Based on previous findings, QSM values ​​increase proportionally to iron deposition.In this study, the increase in the QSM values ​​of different nuclei of the early mild cognitive impairment (EMCI) stage indicates iron deposition in these participants. In the EMCI group, The QSM value of the bilateral thalamus (P<0.05) and left amygdala (P=0.006) nuclei were higher than in the control group. Based on the results of the receiver operating characteristic curve (ROC) analysis, the left amygdala (P=0.005), left putamen (P=0.002), left thalamus (P=0.05), and right thalamus (P<0.05) have an appropriate sensitivity and specificity to identify the different stages of cognitive disorders.
The left amygdala and bilateral thalamic nuclei are the first areas exposed to iron deposition during cognitive impairment. Mentioned nuclei, especially the left amygdala, have high efficiency and sensitivity for the early detection of cognitive disorders.