title: Functional evaluation of transplanted kidneys using arterial spin labeling MRI.
abstract: OBJECTIVE
  To investigate non-contrast-enhanced arterial spin labeling (ASL) MRI for functional assessment of transplanted kidneys at 1.5 Tesla (T) and 3T.
  
  
  METHODS
  This study was approved by the local ethics committee, and written informed consent was obtained from all participants. Ninety eight renal allograft recipients (mean age, 51.5 ± 14.6 years) were prospectively included in this study. ASL MRI was performed at 1.5T (n = 65) and 3T (n = 33) using a single-slice flow-sensitive alternating inversion recovery true-fast imaging with steady-state precession (FAIR True-FISP) sequence in the paracoronal plane. ASL perfusion was regional analyzed for the renal cortex on parameter maps. ASL was compared between patients with good or moderate allograft function (Group a; estimated glomerular filtration rate [eGFR] > 30 mL/min/1.73 m(2)) and patients with heavily impaired allograft function (Group b; eGFR ≤ 30 mL/min/1.73 m(2)) and correlated to renal function as determined by eGFR.
  
  
  RESULTS
  ASL perfusion and eGFR were comparable at 1.5T (246.9 ± 66.8 mL/100 g/min and 41.9 ± 22.7 mL/min/1.73 m(2)) and 3T (236.5 ± 102.3 mL/100 g/min and 35.9 ± 22.9 mL/min/1.73 m(2)). ASL perfusion was significantly higher in group a (282.7 ± 60.8 mL/100 g/min) as compared to group b (178.2 ± 63.3 mL/100 g/min) (P < 0.0001). ASL perfusion values exhibited a significant correlation with renal function as determined by eGFR (r = 0.59; P < 0.0001).
  
  
  CONCLUSIONS
  Cortical ASL perfusion values differ between patients with good or moderate allograft function and poor allograft function and correlate significantly with allograft function. Our results highlight the potential of ASL MRI for functional evaluation of renal allografts.
authors.affiliation: University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Dusseldorf, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Heusch
authors.forename: Hans-Jörg
authors.initials: HJ
authors.lastname: Wittsack
authors.forename: Dirk
authors.initials: D
authors.lastname: Blondin
authors.forename: Alexandra
authors.initials: A
authors.lastname: Ljimani
authors.forename: Michael
authors.initials: M
authors.lastname: Nguyen-Quang
authors.forename: Petros
authors.initials: P
authors.lastname: Martirosian
authors.forename: Hakan
authors.initials: H
authors.lastname: Zenginli
authors.forename: Philip
authors.initials: P
authors.lastname: Bilk
authors.forename: Patric
authors.initials: P
authors.lastname: Kröpil
authors.forename: Till A
authors.initials: TA
authors.lastname: Heusner
authors.forename: Gerald
authors.initials: G
authors.lastname: Antoch
authors.forename: Rotem S
authors.initials: RS
authors.lastname: Lanzman
mesh_terms: D001783:Blood Flow Velocity; D005260:Female; D006084:Graft Rejection / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D016030:Kidney Transplantation / Q000009:adverse effects; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008875:Middle Aged; D011446:Prospective Studies; D012077:Renal Artery / Q000473:pathology / Q000503:physiopathology*; D012079:Renal Circulation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: ASL perfusion; MRI; renal function; transplanted kidney