[Biochemical cartilage imaging-update 2019]

Cartilage imaging using magnetic resonance imaging (MRI) is increasingly used for early detection of cartilage damage. Biochemical MR methods to assess cartilage damage are essential for optimal treatment planning.

The aim of this review is to provide an update on advanced cartilage imaging based on biochemical MR techniques. The clinical applications and additional benefits compared to conventional MRI are presented.

A literature search of PubMed regarding the clinical applications of various biochemical MR methods and morphological MR imaging was performed.

While T2 mapping can be easily implemented on clinical routine MR scanners, the T1rho method is technically more demanding and is not available on all MR scanners. dGEMRIC, which can be performed with all field strengths, is now severely restricted due to the recent decision of the European Medical Agency (EMA) to withdraw linear gadolinium contrast agents from the market because of proven gadolinium deposition in the brain. Sodium imaging is the most sensitive MRI method for glycosaminoglycan (GAG), but is limited to 7 T. In addition to early diagnosis of cartilage degeneration before morphological changes are visible, biochemical MRI offers predictive markers, e.g., effect of lifestyle changes or assessing results of cartilage repair surgery.

Cartilage imaging based on biochemical MRI allows a shift from qualitative to quantitative MRI. Biochemical MRI plays an increasingly important role in the early diagnosis of cartilage degeneration for monitoring of disease-modifying drugs and as predictive imaging biomarker in clinical diagnostics. In cartilage repair, monitoring of the efficacy of different cartilage repair surgery techniques to develop hyaline-like cartilage can be performed with biochemical MRI.