title: MR elastography in renal transplant patients and correlation with renal allograft biopsy: a feasibility study.
abstract: OBJECTIVE
  Magnetic resonance elastography (MRE) images the propagation of mechanical shear waves in tissue and uses that information to generate quantitative measures of tissue stiffness. Hepatic MRE has been successfully performed in thousands of patients, with good correlation between histologic grade of fibrosis and tissue stiffness. There has been no prior investigation of the utility of MRE for the assessment of kidney transplants. The aims of this study were to prospectively evaluate the feasibility of MRE in a small group of kidney transplant recipients and to correlate the measured magnetic resonance elastographic stiffness values with biopsy-proven histopathologic fibrosis.
  
  
  METHODS
  MRE of renal transplants was performed in 11 patients returning for protocol allograft biopsies. Calculated tissue stiffness values were compared to histologic degree of fibrosis in nine of the 11 patients.
  
  
  RESULTS
  The mean stiffness of two patients with moderate interstitial fibrosis was higher than the mean of six patients with mild interstitial fibrosis, but not significantly so (90 Hz, P = .12; 120 Hz, P = .17; 150 Hz, P = .26). The mean stiffness of the two patients with moderate interstitial fibrosis was slightly greater than the mean of one patient with no significant interstitial fibrosis at 90 Hz (P = .78) and slightly less at 120 and 150 Hz (P = .88 and P = .76). The mean stiffness of the six patients with mild interstitial fibrosis did not differ significantly from that of the one patient with no interstitial fibrosis (90 Hz, P = .35; 120 Hz, P = .22; 150 Hz, P = .16).
  
  
  CONCLUSIONS
  Preliminary results demonstrate feasibility and support known multifactorial influences on renal stiffness.
authors.affiliation: Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA. lee.christine@mayo.edu
authors.forename: Christine U
authors.initials: CU
authors.lastname: Lee
authors.forename: James F
authors.initials: JF
authors.lastname: Glockner
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Glaser
authors.forename: Meng
authors.initials: M
authors.lastname: Yin
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Akira
authors.initials: A
authors.lastname: Kawashima
authors.forename: Bohyun
authors.initials: B
authors.lastname: Kim
authors.forename: Walter K
authors.initials: WK
authors.lastname: Kremers
authors.forename: Richard L
authors.initials: RL
authors.lastname: Ehman
authors.forename: James M
authors.initials: JM
authors.lastname: Gloor
mesh_terms: D000328:Adult; D000368:Aged; D001707:Biopsy, Needle; D054459:Elasticity Imaging Techniques; D005240:Feasibility Studies; D005260:Female; D005355:Fibrosis / Q000473:pathology; D006801:Humans; D007668:Kidney / Q000473:pathology* / Q000503:physiopathology; D016030:Kidney Transplantation; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D014184:Transplantation, Homologous