title: Hemisphere, gender and age-related effects on iron deposition in deep gray matter revealed by quantitative susceptibility mapping.
abstract: The purpose of this work was to investigate the effects of hemispheric location, gender and age on susceptibility value, as well as the association between susceptibility value and diffusional metrics, in deep gray matter. Iron content was estimated in vivo using quantitative susceptibility mapping. Microstructure was probed using diffusional kurtosis imaging. Regional susceptibility and diffusional metrics were measured for the putamen, caudate nucleus, globus pallidus, thalamus, substantia nigra and red nucleus in 42 healthy adults (age range 25-78 years). Susceptibility value was significantly higher in the left than the right side of the caudate nucleus (P = 0.043) and substantia nigra (P < 0.001). Women exhibited lower susceptibility values than men in the thalamus (P < 0.001) and red nucleus (P = 0.032). Significant age-related increases of susceptibility were observed in the putamen (P < 0.001), red nucleus (P < 0.001), substantia nigra (P = 0.004), caudate nucleus (P < 0.001) and globus pallidus (P = 0.017). The putamen exhibited the highest rate of iron accumulation with aging (slope of linear regression = 0.73 × 10(-3) ppm/year), which was nearly twice those in substantia nigra (slope = 0.40 × 10(-3) ppm/year) and caudate nucleus (slope = 0.39 × 10(-3) ppm/year). Significant positive correlations between the susceptibility value and diffusion measurements were observed for fractional anisotropy (P = 0.045) and mean kurtosis (P = 0.048) in the putamen without controlling for age. Neither correlation was significant after controlling for age. Hemisphere, gender and age-related differences in iron measurements were observed in deep gray matter. Notably, the putamen exhibited the highest rate of increase in susceptibility with aging. Correlations between susceptibility value and microstructural measurements were inconclusive. These findings could provide new clues for unveiling mechanisms underlying iron-related neurodegenerative diseases.
authors: Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
authors: Nan-Jie
authors: http://orcid.org/0000-0001-9249-413X
authors: NJ
authors: Gong
authors: Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
authors: Chun-Sing
authors: CS
authors: Wong
authors: Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
authors: Edward S
authors: ES
authors: Hui
authors: Department of Geriatrics and Medicine, United Christian Hospital, Hong Kong, China.
authors: Chun-Chung
authors: CC
authors: Chan
authors: Department of Psychiatry, United Christian Hospital, Hong Kong, China.
authors: Lam-Ming
authors: LM
authors: Leung
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism*; D001923:Brain Chemistry; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004198:Disease Susceptibility; D004292:Dominance, Cerebral; D005260:Female; D066128:Gray Matter / Q000737:chemistry*; D006801:Humans; D007501:Iron / Q000032:analysis*; D019190:Iron Overload / Q000150:complications / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D010300:Parkinson Disease / Q000209:etiology; D012727:Sex Characteristics
chemical_list: D007501:Iron
keywords: age; diffusional kurtosis imaging; iron; magnetic susceptibility; putamen; susceptibility mapping