Figure 4c:

Sagittal intermediate-weighted fat-saturated two-dimensional fast spin-echo MR images of the right knee in two subjects with signal abnormalities at baseline and with focal defects after 48 months. (a) Inhomogeneous signal abnormality in the lateral tibia at baseline. Hypointense (white arrows) and hyperintense (black arrows) areas can be seen. (b) Development of a full-thickness defect in the same location as in a (arrow) (WORMS grade, 2.5) at 48 months with adjacent BMEP (arrowhead). (c) Hyperintense signal abnormality with swelling in the trochlea at baseline (arrows). (d) Development of a full-thickness defect (arrow) (WORMS grade 5) at 48 months with adjacent BMEP (arrowheads) in the same patient as in c.