Effect of age on substantia nigra subregions using Neuromelanin-sensitive-MRI overlapping on a 3D T2*-weighted contrast image

Motivation: The signal intensity of neuromelanin and iron concentration in substantia nigra (SN) increase with age, but may vary within the SN subregions. Goal(s): We aimed to investigated the effect of age on NM-MRI measures in SN subregions overlapped on a T2*-weighted contrast MR images, and discuss the age-related changes in iron concentration within these subregions. Approach: Ninety-one participants aged 18-84 years underwent NM-MRI and a T2*-weighted sequences scans. The effect of age on NM-MRI measures and iron concentration in SN subregions were analyzed using polynomial regression. Results: The effect of age on NM-MRI measures and iron concentration varied across SN subregions. Impact: Age exerts an effect on the NM-MRI measures and iron concentration in the SN subregions, which implies that the regions of SN need to be subdivided and the effect of age should be taken into consideration in diseases researches.