Magnetic Resonance Imaging of Articular Cartilage within the Knee.

Magnetic resonance imaging (MRI) provides an effective and noninvasive means by which to evaluate articular cartilage within the knee. Existing techniques can be utilized to detect and monitor longitudinal changes in cartilage status due to injury or progression of degenerative disease. Quantitative MRI (qMRI) techniques can provide a metric by which to evaluate the efficacy of cartilage repair techniques and offer insight into the composition of cartilage and cartilage repair tissue. In this review, we provide background on MR signal generation and decay, the utility of morphologic MRI assessment, and qMRI techniques for the biochemical assessment of cartilage (dGEMRIC, T2, T2*, T1ρ, sodium, gagCEST). Finally, the description and utility of these qMRI techniques for the evaluation of cartilage repair are discussed.