Observer agreement analysis of MRI grading of knee osteoarthritis.

The aim of the study was to use Kappa statistical analysis to assess the inter and intraobserver agreement of the interpretation of the osteoarthritis changes observed on a FISP sequence, 1.0 Tesla, MRI analysis of the articular cartilage in 30 knees. The images were read on two separate occasions by three observers. The best agreement was seen in the patello-femoral compartment. The most experienced of the assessors produced the more consistent results. The results of the interobserver agreement had mainly "slight" or "fair" agreement. Our results are disappointing and accordingly, we have reservations about the use of MRI in the assessment of osteoarthritis of the knee.