Diagnosis of early stages of osteoarthritis in MRI

Plain radiographs are not suitable for detection of early stages of osteoarthritis. Up to now MRI is the only non-invasive method for imaging of the cartilage layer. According to the current literature deep fis fissures and full thickness cartilage defects of the cartilage can be detected with the help of MRI before changes in plain radiographs occure. The grading of cartilage fibrillations and superficial fissures is not possible with high reliability. Depending on the grade of osteoarthrosis changes of T-1- and T-2-relaxation times and differences of the signal intensity can be seen. However, up to now no reliable grading system of degenerative cartilage changes exists by the means of signal intensity measurements or by determining T-1- and T-2-relaxation times. Correlations of signal intensities of the cartilage layer with biochemical analysis of the cartilage have been found, but only little information exists about the influence of the composition of cartilage on the MRI signal.