MRI of the cartilage

With the introduction of fat-suppressed gradient-echo and fast spin-echo (FSE) sequences in clinical routine MR visualization of the hyaline articular cartilage is routinely possible in the larger joints. While 3D gradient-echo with fat suppression allows exact depiction of the thickness and surface of cartilage, FSE outlines the normal and abnormal internal structures of the hyaline cartilage; therefore, both sequences seem to be necessary in a standard MRI protocol for cartilage visualization. In diagnostically ambiguous cases, in which important therapeutic decisions are required, direct MR arthrography is the established imaging standard as an add-on procedure. Despite the social impact and prevalence, until recent years there was a paucity of knowledge about the pathogenesis of cartilage damage. With the introduction of high-resolution MRI with powerful surface coils and fat-suppression techniques, visualization of the articular cartilage is now routinely possible in many joints. After a short summary of the anatomy and physiology of the hyaline cartilage, the different MR imaging methods are discussed and recommended standards are suggested.