title: Quantifying brain iron deposition in patients with Parkinson's disease using quantitative susceptibility mapping, R2 and R2.
abstract: OBJECTIVE
  To evaluate the sensitivity and specificity of quantitative magnetic resonance (MR) iron mapping including R2, R2* and magnetic susceptibility to differentiate patients with Parkinson's disease (PD) from healthy controls.
  
  
  METHODS
  Thirty (30) healthy controls (HC) (64±7years old) and 20 patients with idiopathic PD (66±8years old) were studied using a 3T MR imaging scanner. R2 maps were generated from GRASE sequence while R2*, and quantitative susceptibility mapping (QSM) were obtained from a conventional multi-echo gradient-echo sequence. R2, R2* and relative susceptibility (Δχ) values of structures in the basal ganglia were measured for each patient and control. An analysis of sensitivity and specificity and unpaired t-test was applied to the two groups.
  
  
  RESULTS
  A significant difference (p<0.05) was found for R2 and ∆χ values in the substantia nigra as a whole and in the pars compacta for PD patients. The R2* values were different significantly (p<0.05) only on the substantia nigra pars compacta. QSM presented the highest sensitivity and specificity to differentiate the two populations.
  
  
  CONCLUSIONS
  The QSM map was the most sensitive quantitative technique for detecting a significant increase of iron for PD. The highest significant difference between controls and patients was found in the substantia nigra pars compacta using QSM.
authors.affiliation: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil. Electronic address: jeamharoldo@hotmail.com.
authors.forename: Jeam Haroldo Oliveira
authors.initials: JH
authors.lastname: Barbosa
authors.affiliation: Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Antonio Carlos
authors.initials: AC
authors.lastname: Santos
authors.affiliation: Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Vitor
authors.initials: V
authors.lastname: Tumas
authors.affiliation: MRI Institute for Biomedical Research, Detroit, MI, United States.
authors.forename: Manju
authors.initials: M
authors.lastname: Liu
authors.affiliation: MRI Institute for Biomedical Research, Detroit, MI, United States.
authors.forename: Weili
authors.initials: W
authors.lastname: Zheng
authors.affiliation: MRI Institute for Biomedical Research, Detroit, MI, United States; Wayne State University, Detroit, MI, United States.
authors.forename: E Mark
authors.initials: EM
authors.lastname: Haacke
authors.affiliation: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Carlos Ernesto Garrido
authors.initials: CE
authors.lastname: Salmon
mesh_terms: D000368:Aged; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D001931:Brain Mapping / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007501:Iron / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000378:metabolism* / Q000473:pathology; D012680:Sensitivity and Specificity
chemical_list: D007501:Iron
keywords: Brain; Iron; Parkinson; QSM; Susceptibility magnetic