title: Reliability of magnetic resonance elastography using multislice two-dimensional spin-echo echo-planar imaging (SE-EPI) and three-dimensional inversion reconstruction for assessing renal stiffness.
abstract: BACKGROUND
  To evaluate the reliability of MRE using a spin-echo echo-planar imaging (SE-EPI) renal MRE technique in healthy volunteers.
  
  
  METHODS
  Institutional review board approved prospective study in which all participants provided written informed consent. Sixteen healthy volunteers comprising seven males and nine females with a median age of 35 years (age range: 23 to 59 years) were included. Coronal 90 Hz and 60 Hz MRE acquisitions were performed twice within a 30-min interval between examinations. Renal MRE reliability was assessed by (i) test-retest repeatability, and (ii) inter-rater agreement between two independent readers. The MRE-measured averaged renal stiffness values were evaluated using: intraclass correlation coefficient (ICC), Bland-Altman and the within-subject coefficient of variation (COV).
  
  
  RESULTS
  For test-retest repeatability, Bland-Altman showed a mean stiffness difference between examinations of 0.07 kPa (95% limits of agreement: -1.41, 1.54) at 90 Hz and 0.01 kPa (95% limits of agreement: -0.51, 0.53) at 60 Hz. Coefficient of repeatability was 1.47 kPa and 0.52 kPa at 90 Hz and 60 Hz, respectively. The within-subject COV was 13.6% and 7.7% at 90 Hz and 60 Hz, respectively. ICC values were 0.922 and 0.907 for test-retest repeatability and 0.998 and 0.989 for inter-rater agreement, respectively (P < 0.001).
  
  
  CONCLUSIONS
  SE-EPI renal MRE is a reliable technique.
authors.affiliation: Department of Radiology, Addenbrooke's Hospital, University of Cambridge, England, United Kingdom.|University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Gavin
authors.initials: G
authors.lastname: Low
authors.affiliation: Division of Gastroenterology & Hepatology, Cambridge University Hospitals NHS Foundation Trust Hospital, England, United Kingdom.
authors.forename: Nicola E
authors.initials: NE
authors.lastname: Owen
authors.affiliation: Department of Radiology, Addenbrooke's Hospital, University of Cambridge, England, United Kingdom.
authors.forename: Ilse
authors.initials: I
authors.lastname: Joubert
authors.affiliation: Department of Radiology, Addenbrooke's Hospital, University of Cambridge, England, United Kingdom.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Patterson
authors.affiliation: Department of Radiology, Addenbrooke's Hospital, University of Cambridge, England, United Kingdom.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Graves
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Glaser
authors.affiliation: Division of Gastroenterology & Hepatology, Cambridge University Hospitals NHS Foundation Trust Hospital, England, United Kingdom.
authors.forename: Graeme J M
authors.initials: GJ
authors.lastname: Alexander
authors.affiliation: Department of Radiology, Addenbrooke's Hospital, University of Cambridge, England, United Kingdom.
authors.forename: David J
authors.initials: DJ
authors.lastname: Lomas
mesh_terms: D000328:Adult; D017352:Echo-Planar Imaging; D054459:Elasticity Imaging Techniques; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007668:Kidney / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D015203:Reproducibility of Results; D055815:Young Adult
keywords: diagnostic reliability; kidneys; magnetic resonance elastography