title: Intravoxel incoherent motion imaging of the kidney: alterations in diffusion and perfusion in patients with renal dysfunction.
abstract: OBJECTIVE
  To investigate the relationship between estimated glomerular filtration rate (eGFR) and parameters calculated using intravoxel incoherent motion (IVIM) imaging of the kidneys.
  
  
  METHODS
  We studied 365 patients, divided into 4 groups based on eGFR levels (mL/min/1.73m(2)): group 1, eGFR≥80(n=80); group 2, eGFR 60-80 (n=156); group 3, eGFR 30-60 (n=114); and group 4 ,eGFR<30 (n=15). IVIM imaging was used to acquire diffusion-weighted images at 12 b values. The diffusion coefficient of pure molecular diffusion (D), the diffusion coefficient of microcirculation or perfusion (D*), and perfusion fraction (f) were compared among the groups using group 1 as control.
  
  
  RESULTS
  In the renal cortex, D* values were significantly lower in groups 2, 3, and 4 than in group 1. The D value of renal cortex was significantly low in only group 3. In the renal medulla, the D* and D values were significantly lower only in groups 2 and 3, respectively.
  
  
  CONCLUSIONS
  As renal dysfunction progresses, renal perfusion might be reduced earlier and affected more than molecular diffusion in the renal cortex. These changes are effectively detected by IVIM MR imaging.
authors.affiliation: Department of Radiology, University of Yamanashi, Yamanashi, Japan. ichikawa@yamanashi.ac.jp
authors.forename: Shintaro
authors.initials: S
authors.lastname: Ichikawa
authors.forename: Utaroh
authors.initials: U
authors.lastname: Motosugi
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Ichikawa
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Sano
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Morisaka
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Araki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001783:Blood Flow Velocity; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007674:Kidney Diseases / Q000473:pathology* / Q000503:physiopathology*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012079:Renal Circulation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult