Baseline mean and heterogeneity of MR cartilage T ₂ are associated with morphologic degeneration of cartilage, meniscus, and bone marrow over 3years - data from the Osteoarthritis Initiative

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 3years in subjects with risk factors for osteoarthritis (OA). Design: Subjects with risk factors for OA (n=289) with an age range of 45-55years 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 3years. 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 3years 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 3years. Conclusions: The prevalence of knee abnormalities significantly increased over 3years; increased cartilage T ₂ at baseline predicted longitudinal morphologic degeneration in the cartilage, meniscus, and bone marrow over 3years in subjects with risk factors for OA.