"Articular cartilage is hyaline cartilage and is composed of a low density of chondrocytes surrounded by an abundant extracellular matrix. The extracellular matrix consists of water, collagen, an amorphous ground substance of proteoglycan aggregates, rich in glycosaminoglycans and a small amount of non-collagenous proteins and glycoproteins 1,2. Like other types of hyaline cartilage, it is characterised by a simple anatomical structure and a firm consistency. It does not contain any blood vessels, lymphatics or nerves 1,2, and it has a translucent, glassy pearl-white to bluish appearance 2."
"intermediate or transitional zone (~ 40-60% of articular cartilage volume):"
"T1: intermediate signal intensity"
"T2: low signal intensity"
"PD: intermediate to mildly hyperintense signal intensity"
"PDFS/STIR: mildly hyperintense signal intensity"
"Articular cartilage is surrounded by joint fluid produced by the adjacent synovial membrane, or it is bordering the subchondral bone plate. It is in close contact with other cartilaginous structures in some joints as menisci or articular disks, which consist of fibrocartilage."
"T1: intermediate signal intensity"
"T2: low signal intensity"
"PD: intermediate to mildly hyperintense signal intensity"
"PDFS/STIR: mildly hyperintense signal intensity"
"collagen: T2 mapping, DWI/DTI"
"However, those techniques are still more subject to research than to clinical application. This is due to demanding technical requirements (e.g. specific RF pulse, 7T magnet), contrast media-related issues and low reproducibility between different vendors 4,5."
Expected headings
"Relations and/or boundaries"
"Signal characteristics"
"Articular cartilage is hyaline cartilage and is composed of a low density of chondrocytes surrounded by an abundant extracellular matrix. The extracellular matrix consists of water, collagen, an amorphous ground substance of proteoglycan aggregates, rich in glycosaminoglycans and a small amount of non-collagenous proteins and glycoproteins 1,2. Like other types of hyaline cartilage, it is characterised by a simple anatomical structure and a firm consistency. It does not contain any blood vessels, lymphatics or nerves 1,2, and it has a translucent, glassy pearl-white to bluish appearance 2."
"The main function of hyaline cartilage is the absorption and distribution of loading forces and, to a lesser degree, tensile forces while providing low friction on its surface to facilitate smooth movements 2,3. The water that is bound within the extracellular matrix has an important role in buffering compressive loading forces. When applied, these cause an immediate rise in interstitial fluid pressure and squeeze the water slowly out of the extracellular matrix creating a large frictional resistance due to its low permeability; once the compressive loading forces subside, the interstitial fluid flows back in 1."
"There are several functional approaches for the evaluation of articular cartilage available which target the following extracellular matrix components 4:"