Brain iron deposition analysis using susceptibility weighted imaging and its association with body iron level in patients with mild cognitive impairment

The aim of the present study was to analyze brain and body iron levels among patients with mild cognitive impairment (MCI), Alzheimer's disease (AD), and normal controls (NCs). A total of 90 participants (30 MCI, 30 AD, 30 NC) were enrolled. Brain iron content was quantified using susceptibility weighted imaging (SWI). Phase values were used to calculate bilateral iron content in the hippocampus (HP), substantia nigra, red nucleus (RN), dentate nucleus (DN), caudate nucleus (CN), globus pallidus (GP), putamen (PUT), frontal white matter, temporal cortex (TC), and parietal cortex. Body iron indices, including serum iron, serum transferrin, ferritin and total iron binding capacity, were measured. Phase values of the left (L)-DN, L-CN, and bilateral PUT in the MCI group were significantly lower compared with NC group. Phase values of the right (R)-RN, bilateral DN, and bilateral PUT in the AD group were significantly lower compared with the MCI group. Phase values of the bilateral HP, DN, RN, CN, GP, PUT, and L-TC in the AD group were significantly lower compared with the NC group. Serum ferritin levels in the MCI and AD groups were significantly lower compared with the NC group. Only serum iron in the AD group was positively associated with iron content in the R-HP. Brain iron deposition and body iron levels both increased in MCI and AD patients, however, excessive brain iron accumulation may have no association with body iron level. SWI was particularly effective at recognizing the presence of brain iron in the MCI and AD groups.