title: Baseline mean and heterogeneity of MR cartilage T2 are associated with morphologic degeneration of cartilage, meniscus, and bone marrow over 3 years--data from the Osteoarthritis Initiative.
abstract: OBJECTIVE
  The purpose of this study is to determine whether the mean and heterogeneity of magnetic resonance (MR) knee cartilage T(2) relaxation time measurements at baseline are associated with morphologic degeneration of cartilage, meniscus, and bone marrow tissues over 3 years in subjects with risk factors for osteoarthritis (OA).
  
  
  METHODS
  Subjects with risk factors for OA (n=289) with an age range of 45-55 years were selected from the Osteoarthritis Initiative (OAI) database. 3.0 Tesla MR images were analyzed using morphological gradings of cartilage, bone marrow and menisci whole-organ magnetic resonance imaging scores (WORMS scoring). A T(2) mapping sequence was used to assess the mean and heterogeneity of cartilage T(2) (gray level co-occurrence matrix texture analysis). Regression models were used to assess the relationship between baseline T(2) parameters and changes in morphologic knee WORMS scores over 3 years.
  
  
  RESULTS
  The prevalence of knee abnormalities in the cartilage (P<0.0005), meniscus (P<0.00001), and bone marrow significantly (P<0.00001) increased from baseline to 3 years in all compartments combined. The baseline mean and heterogeneity of cartilage T(2) were significantly (P<0.05) associated with morphologic joint degeneration in the cartilage, meniscus and bone marrow over 3 years.
  
  
  CONCLUSIONS
  The prevalence of knee abnormalities significantly increased over 3 years; increased cartilage T(2) at baseline predicted longitudinal morphologic degeneration in the cartilage, meniscus, and bone marrow over 3 years in subjects with risk factors for OA.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94158, USA. gabby.joseph@ucsf.edu
authors.forename: G B
authors.initials: GB
authors.lastname: Joseph
authors.forename: T
authors.initials: T
authors.lastname: Baum
authors.forename: H
authors.initials: H
authors.lastname: Alizai
authors.forename: J
authors.initials: J
authors.lastname: Carballido-Gamio
authors.forename: L
authors.initials: L
authors.lastname: Nardo
authors.forename: W
authors.initials: W
authors.lastname: Virayavanich
authors.forename: J A
authors.initials: JA
authors.lastname: Lynch
authors.forename: M C
authors.initials: MC
authors.lastname: Nevitt
authors.forename: C E
authors.initials: CE
authors.lastname: McCulloch
authors.forename: S
authors.initials: S
authors.lastname: Majumdar
authors.forename: T M
authors.initials: TM
authors.lastname: Link
mesh_terms: D000368:Aged; D001853:Bone Marrow / Q000473:pathology*; D002358:Cartilage, Articular / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008592:Menisci, Tibial / Q000473:pathology*; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000175:diagnosis* / Q000473:pathology; D011379:Prognosis; D015203:Reproducibility of Results; D012307:Risk Factors; D012720:Severity of Illness Index