title: Quantitative T2* magnetic resonance imaging for renal iron overload assessment: normal values by age and sex.
abstract: OBJECTIVE
  Few studies of renal iron content have been performed with multiecho gradient-echo (ME-GRE) T2* magnetic resonance imaging (MRI). We assessed the feasibility and reproducibility of ME-GRE T2* MRI for measuring regional and global renal T2* values, and established the lower limits of normal in healthy subjects, also correlating the measured values with age and sex.
  
  
  METHODS
  Twenty consecutive healthy subjects (13 men and 7 women, mean age 29.1 ± 7.2 years, range 19-42 years) underwent MRI examinations using a 1.5 T magnet and an ME-GRE T2* sequence. For each kidney, T2* was measured in anterior, posterolateral, and posteromedial renal parenchymal regions. The mean T2* value was calculated as the average of the two kidneys T2* values.
  
  
  RESULTS
  For the mean kidney T2* value, the coefficients of variation for intra- and inter-operator reproducibility were 1.76% and 6.23%, respectively. The lower limit of normal for the mean kidney T2* value was 31 ms (median 51.39 ± 10.09). There was no significant difference between left and right kidney T2* values (p = 0.578). No significant correlation was found between T2* values and subjects' age or sex.
  
  
  CONCLUSIONS
  Renal ME-GRE T2* appears to be a feasible and reproducible technique. The renal T2* values showed no dependence on sex or age.
authors.affiliation: Istituto di Radiologia, DIBIMED, University of Palermo, Palermo, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Grassedonio
authors.forename: Antonella
authors.initials: A
authors.lastname: Meloni
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Positano
authors.forename: Daniele
authors.initials: D
authors.lastname: De Marchi
authors.forename: Patrizia
authors.initials: P
authors.lastname: Toia
authors.forename: Massimo
authors.initials: M
authors.lastname: Midiri
authors.forename: Alessia
authors.initials: A
authors.lastname: Pepe
mesh_terms: D000328:Adult; D000367:Age Factors; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement; D019190:Iron Overload / Q000175:diagnosis*; D007668:Kidney / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012737:Sex Factors; D055815:Young Adult