title: Assessment of renal dysfunction with diffusion-weighted imaging: comparing intra-voxel incoherent motion (IVIM) with a mono-exponential model.
abstract: BACKGROUND
  Because renal dysfunction is a worldwide problem, accurate assessment is required for planning treatment and follow-up. Intra-voxel incoherent motion (IVIM) can isolate fast from slow water motion in well-perfused organs and may be helpful in assessing renal dysfunction.
  
  
  OBJECTIVE
  To determine the clinical value of IVIM in the assessment of renal dysfunction compared with a mono-exponential model.
  
  
  METHODS
  Fifty-four consecutive participants (mean age, 53.13 ± 13.96 years) were recruited into this study. The estimated glomerular filtration rate (eGFR) was calculated to classify the participants as having severe renal injury (sRI, eGFR ≤ 30 mL/min/1.73 m(2)) or not (non-sRI). DWI with seven b-factors was performed. Image analysis was performed by a radiologist to generate an apparent diffusion coefficient map (ADCmon) by mono-exponential model, diffusion coefficient (Dslow and Dfast), and fraction of fast diffusion (Ffast) maps by IVIM. The circular regions of interest were placed at the interface between the cortex and medulla for parameter measurements.
  
  
  RESULTS
  The ADCmon, Dslow, Dfast, and Ffast were less in sRI than non-sRI (P < 0.05). ADCmon and Dslow were positively related with eGFR (P < 0.05). For differentiating sRI from non-sRI, receiver operating characteristic curve indicated no significant difference between the two methods (P > 0.05). Furthermore, the correlation was 0.93 between ADCmon and Dslow, followed by 0.57 between Dfast and Ffast, 0.48 between ADCmon and Dfast, and 0.34 between ADCmon and Ffast (P < 0.05).
  
  
  CONCLUSIONS
  The IVIM model contributed little to improving the assessment of renal dysfunction compared with a mono-exponential model.
authors.affiliation: Department of Radiology, Third Affiliated Hospital of Suzhou University, Changzhou, Jiangsu, PR China.
authors.forename: Jiule
authors.initials: J
authors.lastname: Ding
authors.affiliation: Department of Radiology, Third Affiliated Hospital of Suzhou University, Changzhou, Jiangsu, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Radiology, Third Affiliated Hospital of Suzhou University, Changzhou, Jiangsu, PR China.
authors.forename: Zhenxing
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: Department of Nephrology, Third Affiliated Hospital of Suzhou University, Changzhou, Jiangsu, PR China.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Department of Nephrology, Third Affiliated Hospital of Suzhou University, Changzhou, Jiangsu, PR China.
authors.forename: Jia
authors.initials: J
authors.lastname: Di
authors.affiliation: Department of Radiology, Third Affiliated Hospital of Suzhou University, Changzhou, Jiangsu, PR China suzhxingwei@126.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Xing
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D007674:Kidney Diseases / Q000175:diagnosis* / Q000503:physiopathology*; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D009038:Motion; D012372:ROC Curve; D015203:Reproducibility of Results; D055815:Young Adult
keywords: Magnetic resonance imaging (MRI); diffusion-weighted imaging; renal function