Magnetic resonance imaging (MRI) remains the imaging method of choice for depicting the morphological changes associated with osteoarthritis (OA) and other diseases of cartilage, but the early stages of OA are characterized by tissue level changes which are not evident with standard MRI protocols. Several emerging MR-based techniques show promise for detecting changes in water, collagen, and proteoglycans that are the hallmarks of cartilage degeneration. In this review, the principles and application of several of these techniques, including T2 mapping, T1ρ imaging, delayed gadolinium MRI of cartilage (dGEMRIC), and sodium MRI are outlined and compared.