title: Relationship between the renal apparent diffusion coefficient and glomerular filtration rate: preliminary experience.
abstract: OBJECTIVE
  To investigate the relationship between ADC values measured by diffusion-weighted MRI (DWI) and the split glomerular filtration rate (GFR).
  
  
  METHODS
  DWI (b = 0 and 500 seconds/mm(2)) was performed with a 1.5 T MR unit in 55 patients. The ADCs were calculated with ROIs positioned in the renal parenchyma, and the split GFRs were measured by (99)Tc(m)-DTPA scintigraphy using Gates' method. The 110 kidneys were divided into four groups: normal renal function (GFR 40 mL x minute(-1)), mild renal impairment (40 > GFR > or = 20 mL x minute(-1)), moderate renal impairment (20 > GFR > or = 10 mL x minute(-1)), and severe renal impairment (GFR < 10 mL x minute(-1)). The renal ADCs between four groups were statistically compared by analysis of variance (ANOVA), and the relationship between ADCs and GFR was examined using Pearson's correlation test.
  
  
  RESULTS
  The mean renal ADCs of the four groups were 2.87 +/- 0.11, 2.55 +/- 0.17, 2.29 +/- 0.10, and 2.20 +/- 0.11 x 10(-3)mm(2)/second, respectively. There was a statistically significant difference in renal ADCs among the four groups (P < 0.001). There was a positive correlation between the ADCs and split GFR (r = 0.709).
  
  
  CONCLUSIONS
  The ADCs were significantly lower in impaired kidneys than in normal kidneys, and there was a positive correlation between the ADCs and GFR.
authors.affiliation: Department of Radiology, Peking University First Hospital, Beijing, China.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Xu
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Wang
authors.forename: Xuexiang
authors.initials: X
authors.lastname: Jiang
mesh_terms: D000328:Adult; D000368:Aged; D004058:Diffusion; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging / Q000379:methods; D019275:Radiopharmaceuticals; D012107:Research Design; D016284:Technetium Tc 99m Pentetate
chemical_list: D019275:Radiopharmaceuticals; D016284:Technetium Tc 99m Pentetate