Measurement of cartilage thickness in the human knee-joint by magnetic resonance imaging using a three-dimensional gradient-echo sequence

We studied human specimens and compared data on cartilage thickness measure ments with magnetic resonance imaging by using an image analysing system wi th corresponding histological sections in the middle of each sector. The fi ndings are based on 768 measurements in 26 knee joints. Overall, there was very good magnetic resonance/anatomic correlation (r=0.88). The poorest cor relation was in the sectors of the femur (r=0.69). The correlation seemed n ot to be dependent on the grade of osteoarthritic cartilage lesions. Despit e good correlation rates, the mean magnetic resonance/anatomic difference ( absolute values) was 0.41 mm (standard deviation (SD) 0.34 mm) or 18.08% (S D 18.9%). Imaging techniques need to be improved if the assessment of carti lage thickness by this means is to be of clinical relevance.