Figure 3a. Cartilage defect. Sagittal 3D spoiled GRE (a) and T2-weighted fast SE (b) images show a partial-thickness cartilage defect in the medial femoral condyle (solid arrow). Note that fluid (dashed arrow) is dark on the 3D spoiled GRE image (a), whereas it provides an outline of the defect on the T2-weighted fast SE image (b).