Due to the complex, zonally anisotropic internal structure of cartilage resulting in a short T2 relaxation time and because of its thin layer, MRI of articular cartilage is still challenging. Therefore, the highest morphological resolutions at an acceptable signal-to-noise ratio (SNR) are required. Imaging of the articular cartilage is possible at most clinically available MR systems, but it has been shown that a voxel size lower than 300µm is required to reveal fraying of the cartilage. High-field MR scanner, like 3 Tesla and recently ultrahigh field systems operating at 7 Tesla, are able to provide such resolutions in reasonable scan times. Another important part of the hardware is the coil technology with dedicated multi-element coils offering high spatial resolution. These systems provide also the opportunity of 3-D acquisition with high resolution, high SNR and high contrast-to-noise ratio. The use of cartilage-specific sequences combined with a high resolution allows the demonstration of damaged cartilage in a very early stage. The most widespread cartilage-specific MRI techniques are:Intermediate-weighted fast spin-echo (FSE) and 3-D fat-suppressed gradient-echo (GRE) acquisition Each technique has particular properties that complement each other.
With sufficient SNR provided by high field MR advanced compositional or biochemical MR imaging of the main components of cartilage such as proteoglycans and collagen fiber network are feasible.
Disclosure of Interest None Declared