title: Diffusion tensor imaging of articular cartilage at 3T correlates with histology and biomechanics in a mechanical injury model.
abstract: We establish a mechanical injury model for articular cartilage to assess the sensitivity of diffusion tensor imaging (DTI) in detecting cartilage damage early in time. Mechanical injury provides a more realistic model of cartilage degradation compared with commonly used enzymatic degradation.
  
  
  
  Nine cartilage-on-bone samples were obtained from patients undergoing knee replacement. The 3 Tesla DTI (0.18 × 0.18 × 1 mm3) was performed before, 1 week, and 2 weeks after (zero, mild, and severe) injury, with a clinical radial spin-echo DTI (RAISED) sequence used in our hospital. We performed stress-relaxation tests and used a quasilinear-viscoelastic (QLV) model to characterize cartilage mechanical properties. Serial histology sections were dyed with Safranin-O and given an OARSI grade. We then correlated the changes in DTI parameters with the changes in QLV-parameters and OARSI grades.
  
  
  
  After severe injury the mean diffusivity increased after 1 and 2 weeks, whereas the fractional anisotropy decreased after 2 weeks (P < 0.05). The QLV-parameters and OARSI grades of the severe injury group differed from the baseline with statistical significance. The changes in mean diffusivity across all the samples correlated with the changes in the OARSI grade (r = 0.72) and QLV-parameters (r = -0.75).
  
  
  
  DTI is sensitive in tracking early changes after mechanical injury, and its changes correlate with changes in biomechanics and histology. Magn Reson Med 78:69-78, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
authors.affiliation: Department of Radiology, New York University School of Medicine, New York, New York, USA.
authors.forename: Uran
authors.initials: U
authors.lastname: Ferizi
authors.affiliation: Department of Radiology, New York University School of Medicine, New York, New York, USA.|Centro de Diagnostico Dr. Enrique Rossi, Buenos Aires, Argentina.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Rossi
authors.affiliation: Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, New York, USA.
authors.forename: Youjin
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, New York, USA.
authors.forename: Matin
authors.initials: M
authors.lastname: Lendhey
authors.affiliation: Department of Radiology, New York University School of Medicine, New York, New York, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Teplensky
authors.affiliation: Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, New York, USA.
authors.forename: Oran D
authors.initials: OD
authors.lastname: Kennedy
authors.affiliation: Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, New York, USA.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Kirsch
authors.affiliation: Department of Radiology, New York University School of Medicine, New York, New York, USA.|Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, New York, USA.
authors.forename: Jenny
authors.initials: J
authors.lastname: Bencardino
authors.affiliation: Department of Radiology, New York University School of Medicine, New York, New York, USA.
authors.forename: José G
authors.initials: JG
authors.lastname: Raya
mesh_terms: D000328:Adult; D002358:Cartilage, Articular / Q000000981:diagnostic imaging* / Q000293:injuries* / Q000503:physiopathology; D056324:Diffusion Tensor Imaging / Q000379:methods*; D055119:Elastic Modulus; D005260:Female; D050724:Fractures, Cartilage / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007718:Knee Injuries / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D014783:Viscosity
keywords: articular cartilage; biomechanics; cartilage mechanical injury; diffusion tensor imaging; histology analysis