Visualization by magnetic resonance imaging of focal cartilage lesions in the excised mini-pig knee.

This study showed that magnetic resonance imaging can be used to visualize partial thickness cartilage lesions, 0.7 x 10 mm in area and 0.5 mm in depth, surgically induced in the femur (femoropatellar compartment) of a mini-pig knee joint. Formalin-fixed joints, intact as well as disarticulated, were studied by high resolution imaging using a 2.35 T, 31 cm horizontal-bore superconducting magnet. The two-dimensional and three-dimensional spatial resolutions achievable were as follows: 0.12 x 0.23 mm (two-dimensional) and 0.35 x 0.35 x 0.35 mm (three-dimensional) for the intact joint, and 0.08 x 0.08 mm (two-dimensional) and 0.14 x 0.14 x 0.27 mm (three-dimensional) for the disarticulated joint. These results demonstrate that magnetic resonance imaging, together with edge detection and volume rendering, can be used to visualize focal cartilage lesions.