Delayed gadolinium-enhanced magnetic resonance imaging of the meniscus: an index of meniscal tissue degeneration?

OBJECTIVE: Much attention has been focused recently on the need for a better understanding of the mechanisms and natural progression of knee osteoarthritis (OA), particularly in its early stages. One technique that has been used to investigate early OA is delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), where T1(Gd) (T1 value after penetration of the MRI contrast agent gadopentate dimeglumine [Gd-DTPA(2-)]) is used as an index of the molecular status of articular cartilage. The goal of this study was to explore T1(Gd) in the meniscus and its relationship with articular cartilage T1(Gd) in knee dGEMRIC image data sets.
METHODS: T1(Gd) maps of the meniscus and articular cartilage were made from knee dGEMRIC images obtained from prior studies of dGEMRIC of the knee in 21 asymptomatic subjects and 9 patients with self-reported OA.
RESULTS: T1(Gd) of the meniscus covered a range of values (247-515 msec) and patterns (homogeneous and focal variations). In addition, T1(Gd) of the meniscus correlated with that of articular cartilage (R = 0.38, P = 0.037; R = 0.57, P = 0.001 for correlations of the medial posterior meniscus with the medial femoral and tibial cartilage, respectively; T1[Gd] of the anterior meniscus and lateral compartments also correlated, with R > 0.38 and P < 0.037), potentially demonstrating parallel degradative processes in the knee.
CONCLUSION: While the biophysical basis for the T1(Gd) results relative to meniscus molecular structure needs investigation, these findings introduce a potential means of examining the time course of meniscal tissue change in the development and progression of arthritis.