Figure 17.
Mucoid degeneration of the anterior cruciate ligament (ACL).
On sagittal T1-WI (A), the ACL is of intermediate signal intensity and the ligamentous structure has disappeared. On sagittal FS T2-WI (B), the ACL has a striated pattern with interspersed intact ligamentous fibers, resembling a celery stalk (white arrow). There is also an intraosseous ganglion cyst at the tibial insertion of the ACL (black arrowhead). Axial FS T2-WI (C) demonstrates the intermediate signal of the ACL with interspersed intact ligamentous fibers (black arrow).