title: Knee cartilage T2 characteristics and evolution in relation to morphologic abnormalities detected at 3-T MR imaging: a longitudinal study of the normal control cohort from the Osteoarthritis Initiative.
abstract: OBJECTIVE
  To determine the frequency of degenerative knee morphologic abnormalities in asymptomatic individuals by using 3-T magnetic resonance (MR) imaging and to investigate the characteristics and evolution of cartilage T2 values in relation to morphologic abnormalities with a longitudinal study.
  
  
  METHODS
  The study was approved by the institutional review board and was compliant with HIPAA. Ninety-five asymptomatic subjects aged 45-78 years who were free of risk factors for osteoarthritis (OA) were selected from the Osteoarthritis Initiative normal control cohort and examined with radiography and 3-T MR imaging. Data obtained at both baseline and 2-year follow-up were analyzed. OA-related knee abnormalities were analyzed by using the whole-organ MR imaging score (WORMS). Cartilage T2 maps were generated by using sagittal two-dimensional multiecho spin-echo images of the right knee. Statistical significance was determined with the Student t test, the paired t test, a mixed random effects model, one-way analysis of variance, and a multiple linear regression model.
  
  
  RESULTS
  Knee abnormalities were identified with a high frequency (90% at baseline and 92% at 2-year follow-up). The prevalence of hyaline cartilage lesions was particularly high (86% at baseline and 84% at follow-up). A significant longitudinal increase in T2 was detected in the tibiofemoral cartilage but not the patellofemoral cartilage (P = .0072). The longitudinal change in T2 was significantly associated with worsening of the cartilage WORMS (P = .038).
  
  
  CONCLUSIONS
  Asymptomatic subjects have a high frequency of OA-related morphologic abnormalities. A significant increase in tibiofemoral cartilage T2 was detected over the 2-year period. A greater increase in T2 was associated with increased progression of cartilage morphologic abnormalities.
authors: Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, Calif, USA. jpan4@partners.org
authors: Judong
authors: J
authors: Pan
authors: Jean-Baptiste
authors: JB
authors: Pialat
authors: Tom
authors: T
authors: Joseph
authors: Daniel
authors: D
authors: Kuo
authors: Gabby B
authors: GB
authors: Joseph
authors: Michael C
authors: MC
authors: Nevitt
authors: Thomas M
authors: TM
authors: Link
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D002358:Cartilage, Articular / Q000473:pathology* / Q000503:physiopathology; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007719:Knee Joint / Q000473:pathology* / Q000503:physiopathology; D016014:Linear Models; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000473:pathology* / Q000503:physiopathology; D010147:Pain Measurement; D015203:Reproducibility of Results; D012307:Risk Factors; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires