title: MR diffusion tensor imaging of normal kidneys.
abstract: OBJECTIVE
  To assess the feasibility of diffusion tensor imaging (DTI) of normal kidneys and the influence of hydration state.
  
  
  METHODS
  Ten healthy volunteers underwent renal DTI after fasting for 12 hours and 4 hours, without fasting, and following water diuresis. Medullary and cortical apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values were measured and compared in the four different states of hydration. DTI was performed with a 3T magnetic resonance imaging (MRI) system using fat-saturated single-shot spin-echo echo planar imaging sequence.
  
  
  RESULTS
  ADC of normal cortex (2.387 ± 0.081 × 10(-3) mm(2) /s) was significantly higher (t = 20.126, P = 0) than that of medulla (1.990 ± 0.063 × 10(-3) mm(2) /s). The FA value of normal cortex (0.282 ± 0.017) was significantly lower (t = -42.713, P = 0) than that of medulla (0.447 ± 0.022). The ADC and FA values of the left renal cortex (2.404 ± 0.082 × 10(-3) mm(2) /s, 0.282 ± 0.017) and medulla (2.002 ± 0.081 × 10(-3) mm(2) /s, 0.452 ± 0.024) were not significantly different (P > 0.05) from those of right renal cortex (2.369 ± 0.080 × 10(-3) mm(2) /s, 0.283 ± 0.018) and medulla (1.978 ± 0.039 × 10(-3) mm(2) /s, 0.443 ± 0.019). Values for ADC (×10(-3) mm(2) /s) and FA in the 12-hour fasting, 4-hour fasting, nonfasting, and water diuresis states were 2.372 ± 0.095 and 0.278 ± 0.018, 2.387 ± 0.081 and 0.282 ± 0.017, 2.416 ± 0.051 and 0.279 ± 0.023, 2.421 ± 0.068, and 0.270 ± 0.021, respectively, in cortex, 1.972 ± 0.084 and 0.438 ± 0.014, 1.990 ± 0.063 and 0.447 ± 0.022, 2.021 ± 0.081 and 0.450 ± 0.031, 2.016 ± 0.076 and 0.449 ± 0.028, respectively, in medulla. The ADC and FA values in different hydration states were not significantly different (P > 0.05).
  
  
  CONCLUSIONS
  DTI of normal kidneys is feasible with reproducible ADC and FA values independent of hydration states.
authors.affiliation: Department of Radiology, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China; Department of Radiology, Weifang People's Hospital, Weifang, Shandong, China.
authors.forename: Wen-juan
authors.initials: WJ
authors.lastname: Wang
authors.forename: Margaret H
authors.initials: MH
authors.lastname: Pui
authors.forename: Yan
authors.initials: Y
authors.lastname: Guo
authors.forename: Xiao-shu
authors.initials: XS
authors.lastname: Hu
authors.forename: Huan-jun
authors.initials: HJ
authors.lastname: Wang
authors.forename: Dong
authors.initials: D
authors.lastname: Yang
mesh_terms: D000328:Adult; D016880:Anisotropy; D001834:Body Water / Q000502:physiology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004231:Diuresis / Q000502:physiology; D017352:Echo-Planar Imaging / Q000379:methods*; D005215:Fasting; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007672:Kidney Cortex / Q000033:anatomy & histology* / Q000502:physiology*; D007679:Kidney Medulla / Q000033:anatomy & histology* / Q000502:physiology*; D008297:Male; D012016:Reference Values
keywords: diffusion tensor imaging; diffusion-weighted imaging; kidney; magnetic resonance