55-year-old woman with ACL ganglion cyst. A, Sagittal T2-weighted image shows the ganglion cysts as a bright, well-circumscribed oval region paralleling the fibers of the ACL. Incidentally there is a high riding patella. B, Sagittal T2-weighted image, which shows intact ACL fibers and the periphery of the ganglion cyst. C, Sagittal proton density-weighted images shows the cyst to be of intermediate signal intensity. D, Coronal fat saturated proton density-weighted image which shows a portion of the bright cyst (arrow) in the region of the ACL.