Fig. 1
(a) Sagittal T1-weighted MRI showing a low-signal subchondral lesion of serpiginous morphology. (b, c, d) T2-weighted sequences demonstrated a serpiginous lesion of a relatively disorganized area of edema with hyperintense signal, and focal epiphyseal contour depressions. (e) Axial T1-weighted MRI showing a bilateral large subchondral lesion of isointense. (f) Coronal T-weighted MRI showing necrotic fragments in bilateral femoral head, with mixed increased and reduced signal intensity