New frontiers in cartilage imaging of the hip.

High-resolution MRI for cartilage mapping is a rapidly evolving field that is contributing to a better understanding of osteoarthritis. The basic science of cartilage imaging uses different modalities (such as T1rho, T2 mapping, delayed gadolinium-enhanced MRI of cartilage) and has clinical applicability for treating hip disorders in the young adult. These imaging techniques rely on biomarkers to quantify early cartilage degeneration. The common biomarkers are proteoglycan concentration and collagen integrity. Imaging the hip presents unique challenges because of its sphericity, the close apposition of the two cartilage layers, and the limitations in using surface coils.