title: Age-related iron deposition in the basal ganglia: quantitative analysis in healthy subjects.
abstract: OBJECTIVE
  To determine the values of iron accumulation in the basal ganglia of healthy volunteers of different ages with R2* and raw signal intensity measurements from T1-weighted magnetic resonance (MR) images, supported by voxel-based relaxometry (VBR), and to compare them with previously reported iron concentrations found in autopsy material.
  
  
  METHODS
  The ethics committee approved the study, and the participants or their parents gave written informed consent. Eighty subjects (41 female and 39 male subjects; age range, 1-80 years) were examined at 1.5 T. For each subject, R2* values were calculated. Curves for R2* versus age were obtained for globus pallidus (GP), putamen, caudate nucleus, substantia nigra (SN), and frontal white matter (FWM). To highlight possible differences in iron concentration among the age decades, VBR was applied. Signal intensity values were estimated on T1-weighted fast low-angle shot images, and regions of interest were drawn in each nucleus. R2* values were also compared with iron concentrations reported in a postmortem study. Statistical analysis was performed (t test), and a difference with P < .05 (FDR corrected) was significant.
  
  
  RESULTS
  The curves for R2* versus age showed an exponential increase with increasing age in all the basal ganglia. VBR demonstrated significant differences (P < .05, corrected) in the comparison between the 2nd and the following decades for lenticular nuclei. Good correlation coefficients were found for GP (R(2) = 0.64), putamen (R(2) = 0.51), and SN (R(2) = 0.53) when compared with findings in the postmortem study. Signal intensity curves were similar to the R2* curves.
  
  
  CONCLUSIONS
  R2* measurements can be used to quantify brain iron accumulation and thus may allow better evaluation of neurodegenerative diseases associated with iron deposition.
authors: Departments of Neuroradiology, Foundation IRCCS, C. Besta Neurological Institute, Via Celoria 11, 20133 Milan, Italy.
authors: Domenico
authors: D
authors: Aquino
authors: Alberto
authors: A
authors: Bizzi
authors: Marina
authors: M
authors: Grisoli
authors: Barbara
authors: B
authors: Garavaglia
authors: Maria Grazia
authors: MG
authors: Bruzzone
authors: Nardo
authors: N
authors: Nardocci
authors: Mario
authors: M
authors: Savoiardo
authors: Luisa
authors: L
authors: Chiapparini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism* / Q000473:pathology; D001479:Basal Ganglia / Q000033:anatomy & histology / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007223:Infant; D007501:Iron / Q000032:analysis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D007501:Iron