title: Apparent diffusion coefficient measurements of bilateral kidneys at 3 T MRI: effects of age, gender, and laterality in healthy adults.
abstract: OBJECTIVE
  To investigate the effects of age and gender on apparent diffusion coefficient (ADC) measurements of bilateral kidneys at 3 T MRI, and compare the ADC values of left and right kidneys.
  
  
  METHODS
  In all, 137 healthy participants (mean age 42.8 ± 14.7 years; age range 16-75 years) comprising 68 male and 69 female participants were enrolled. Three Tesla echo-planar diffusion-weighted imaging (DWI) of bilateral kidneys was performed and ADC values were measured in the cortex, medulla, and whole parenchyma. Pearson correlation analysis and linear regression were performed to determine the associations between the ADC values in each region and age. Effects of age and gender on ADC values were analysed using two-factor analysis of variance (ANOVA). The paired-samples t-test was established to compare the ADC values between left and right kidneys.
  
  
  RESULTS
  ADC values were significantly higher in the young group (≤50 years) than in the old group (>50 years), and correlated inversely with the age in all regions. Male participants had higher ADC values than female participants in all regions except left medulla. Two-factor ANOVA of age × gender showed no significant interactions between the variables age and gender were found. No significant differences in ADC values between left and right kidneys were observed.
  
  
  CONCLUSIONS
  Renal ADC values are age- and gender-dependent, and show no significant difference between left and right kidneys. Age- and gender-related effects should be taken into consideration in future renal DWI studies when using normal ADC values from health controls.
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, No. 160, Pujian Rd, Shanghai 200127, China.
authors.forename: S-T
authors.initials: ST
authors.lastname: Suo
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, No. 160, Pujian Rd, Shanghai 200127, China.
authors.forename: M-Q
authors.initials: MQ
authors.lastname: Cao
authors.affiliation: Department of Urinary Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, No. 160, Pujian Rd, Shanghai 200127, China.
authors.forename: Y-Z
authors.initials: YZ
authors.lastname: Ding
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, No. 160, Pujian Rd, Shanghai 200127, China.
authors.forename: Q-Y
authors.initials: QY
authors.lastname: Yao
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, No. 160, Pujian Rd, Shanghai 200127, China.
authors.forename: G-Y
authors.initials: GY
authors.lastname: Wu
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, No. 160, Pujian Rd, Shanghai 200127, China. Electronic address: xujianrong_renji@163.com.
authors.forename: J-R
authors.initials: JR
authors.lastname: Xu
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000473:pathology* / Q000502:physiology*; D000704:Analysis of Variance; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007668:Kidney / Q000033:anatomy & histology* / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012189:Retrospective Studies; D012737:Sex Factors; D055815:Young Adult